Two Betrayals (Level)

Two Betrayals is the eighth level in Halo: Combat Evolved (Halo 1). It is set in the same location as Assault on the Control Room, but this time Master Chief travels in the opposite direction. The objective is to destroy three Phase Pulse Generators while fighting three other factions of enemies striving towards everyone else's destruction. Many gamers find this level confusing because Assault on the Control Room passages can be followed, only to be blocked at the end and make the player go all the way back to the starting point. However, it is popular because many see it as a challenge.

Master Chief, after teleporting back to the Control Room, proceeds to activate Installation 04. However, Cortana, who, after spending twelve hours in the control room, has discovered Halo’s true purpose, stops him just in time. After stealing the Activation Index, she tells the Chief that Halo will wipe out all life in the galaxy, and turns the Chief against the monitor. Spark sends Sentinels to take the Spartan's head, and the AI inside his helmet. After destroying the Sentinels in the Control Room, Cortana tells the Chief to destroy three Phase Pulse Generators to buy some time, in case the Monitor found a way to activate Halo without the index. While Cortana tries to locate the Pillar of Autumn's crash site, you must hijack a Covenant Banshee and set out to destroy the generators. You have no allies on this level.

After you destroy the third pulse generator, Cortana teleports you to a Covenant cruiser: the Truth and Reconciliation. There the level Keyes begins.

Enemies

 * Covenant
 * Grunts
 * Major
 * Elites
 * Minor
 * Major
 * Zealot
 * Stealth
 * Jackals
 * Minor
 * Major
 * Hunters
 * Flood
 * Combat Forms
 * Carrier Forms
 * Infection Forms
 * Forerunner
 * Sentinels

Weapons

 * Pistol
 * Assault Rifle
 * Sniper Rifle
 * Shotgun
 * Rocket Launcher
 * Fragmentation Grenade
 * Plasma Pistol
 * Plasma Rifle
 * Needler
 * Plasma Grenade
 * Shade
 * Fuel Rod Gun (Fail-safe enabled)
 * Energy Sword (non-useable)

Vehicles

 * Warthog
 * Ghost
 * Banshee
 * Wraith (non-drivable)

Equipment

 * Health Pack

Part 01: Two Betrayals
{Cutscene}

''{Opening cinematic---Long shot of the Control Room. Master Chief and 343 Guilty Spark teleport in, obviously in the middle of a conversation}''

343 Guilty Spark: "...which means that any organism of sufficient mass and cognitive capability is a potential vector."

(Master Chief pauses)

343 Guilty Spark: "Is something wrong?"

Master Chief: "No, nothing."

343 Guilty Spark: "Splendid. Shall we?"

{Master Chief and 343 Guilty Spark move up to the main control panel.}

343 Guilty Spark:  " Unfortunately, my usefulness to this particular endeavor has come to an end. Protocol does not allow units with my classification to...perform a task as important as the reunification of the Index with the Core. That final step is reserved for you, Reclaimer."

''{Master Chief takes the Index, and puts it into a slot on the console. Lights and holograms appear, but then fade.}''

343 Guilty Spark: "Odd, that wasn't supposed to happen."

{Cortana suddenly appears over the console.}

Cortana: "Oh, really?!"

{There is a flash of light, and 343 Guilty Spark is thrown back, and down to the ground.}

Master Chief: "Cortana!"

Cortana: "I've spent the last 12 hours cooped up in here, watching you toady about, helping that thing get set to slit our throats!"

Master Chief: "Hold on now, he's a friend."

Cortana: (Mockingly) "Oh! I didn't realize. He's your pal, is he? Your chum? (Angrily) Do you have any idea what that bastard almost made you do?!"

Master Chief: "Yes... Activate Halo's defences, and destroy the Flood, which is why we brought the Index to the Control Center."

Cortana: "You mean this?"

{Index hologram appears in Cortana's hand.}

343 Guilty Spark: "A construct?! In the Core?! That is absolutely unacceptable!"

Cortana: "Sod off!" (or "piss off!" if reading the book Halo: The Flood)

343 Guilty Spark: "What impertinence! I shall purge you at once!"

Cortana: (smiles nastily) "You sure that's a good idea?"

{Cortana's avatar absorbs the Index.}

343 Guilty Spark: "How... How dare you! I'll-"

Cortana: "Do what? I have the Index! You can just float and sputter!"

Master Chief: "Enough! {The Chief brings both hands up in the middle of them as if to stop a fight then turns back round to Cortana} The Flood is spreading. If we activate Halo's defences, we can wipe them out."

Cortana: "You have no idea how this ring works, do you? Why the Forerunners built it? Halo doesn't kill Flood, it kills their food. Humans, Covenant, whatever. We're all equally edible. The only way to stop the Flood is to starve them to death. And that's exactly what Halo is designed to do; wipe the galaxy clean of all sentient life. You don't believe me? Ask him! (Points at Spark)"

{Master Chief hesitates, and then turns to 343 Guilty Spark}

Master Chief: "Is it true?"

343 Guilty Spark: (pauses) "More or less. Technically, this installation's pulse has a maximum effective radius of twenty-five thousand light years. But, once the others follow suit, this galaxy will be quite devoid of life, or at least any life with sufficient biomass to sustain the Flood." (Pause) "But you already knew that... I mean, how couldn't you?"

Cortana: "Left out that little detail, did he?"

343 Guilty Spark: "We have followed outbreak containment procedure to the letter. You were with me each step of the way, as we managed this crisis."

Cortana: (Alarmed) "Chief, I'm picking up movement!"

343 Guilty Spark: "Why would you hesitate to do what you have already done?"

Cortana: (Urgently) "We need to go, right now."

{Sentinels float up behind 343 Guilty Spark, their beams trained menacingly on the Chief}

343 Guilty Spark: "Last time, you asked me, if it was my choice, would I do it? Having had considerable time to ponder your query, my answer has not changed."

''{Master Chief looks around at the Sentinels, and backs towards the panel. He takes Cortana's disk out of the console, and inserts it into his head.}''

343 Guilty Spark: "There is no choice. We must activate the ring."

Cortana: (whispers in Master Chief's head) "Get. Us. Out. Of. Here."

343 Guilty Spark: "If you are unwilling to help, I will simply find another. Still, I must have the Index. Give your construct to me, or I will be forced to take her from you."

Master Chief: "That's not going to happen."

343 Guilty Spark: "So be it. Save his head. Dispose of the rest."

{343 Guilty Spark teleports away, and his Sentinels attack}

{Cutscene ends}

Cortana: "Look out!"

{After the Sentinels are destroyed}

Part 02: The Gun Pointed at the Head of the Universe
Cortana: "We can't let the Monitor activate Halo. We have to stop him. We have to destroy Halo. According to my analysis of the available data, I believe the best course of action is somewhat... risky. An explosion of sufficient size will help destabilize the ring, and will cut through a number of primary systems. We need to trigger a detonation on a large scale, however. A star ship's fusion reactors going critical would do the job. I'm going to search what's left of the Covenant battlenet, and see if I can locate the Pillar of Autumn 's crash site. If the ship's fusion reactors are still relatively intact, we can use them to destroy Halo."

{Once outside, into the canyon}

Cortana: "I haven't located the crash site yet but we need to buy some time, in case the Monitor or his Sentinels find a way to activate Halo's final weapon, without the Index. The machinery in these canyons are Halo's primary firing mechanisms. They consist of three phase pulse generators that amplify Halo's signal, and allow it to fire deep into space. The power levels are enormous. I can't even begin to calculate the pulse's range. So, if we damage or destroy these generators, the Monitor will need to repair them before Halo can be used. That should buy us some time. I'm marking the location of the nearest pulse generator with a nav point. We need to move in and neutralize the device."

{Once down to ground level}

Cortana: "Wait. We should commandeer one of those Banshees; we'll need it to reach the pulse generator in time."

{Once in the Banshee}

Cortana: "Good, let's get moving. The nav point marks our target."

{Once you reach the room the generator is in}

Cortana: "That's the pulse generator. The centre core is the signal amplifier. That's what we need to shut down. We need to interrupt the pulse generator's energy stream. I've adjusted your shield system so that it will deliver an EMP (Electro Magnetic Pulse) burst to disrupt the generator. You will need to walk into the beam, to trigger it. The EMP blast should neutralize the generator. But it will also drain your shields, and you will be vulnerable until they recharge."

{After the generator is neutralized}

Cortana: "Objective accomplished! The pulse generator has overloaded. Outstanding. The generator's central core is offline. Well done."

{After going back outside, to the canyon}

Part 03: Breaking Stuff to Look Tough
Cortana: "The second pulse generator is located in the adjacent canyon. Move out, and I'll mark the target with a nav point when we get closer."

{Once onto the bridge in the middle of this canyon}

Cortana: "Head through that door. That's the way to the next canyon."

(Once to the canyon with the 2nd pulse generator in it)

Cortana: "OK. Lets take care of the next pulse generator."

{If you continue on to toward the 3rd canyon, before destroying the 2nd pulse generator}

Cortana: "Wait! We haven't destroyed the pulse generator yet. Find a Banshee, and fly it up to the location marked by the nav point."

{After you destroy the 2nd generator}

Cortana: "That did it! The pulse generator overloaded. One more to go."

{Once outside again}

Part 04: The Tunnels Below
Cortana: "I've located the Pillar of Autumn. She put down twelve-hundred kilometres up spin. Energy readings show her fusion reactors are still powered up. The systems on the Pillar of Autumn have fail safes that even I can't override, without authorization from the Captain. We'll need to find him or his neural implants, to start the fusion core detonation. One target remaining. Let's take care of the final pulse generator."

{Once you reach the tunnel leading to the 3rd canyon}

Cortana: "That tunnel leads to the next section of the canyon. The final pulse generator we need to destroy is through there."

{Once you enter the 3rd canyon}

Part 05: Final Run
{Cutscene}

{After you destroy the final generator}

Cortana: "Final target neutralized. Let's get out of here."

Master Chief: "Let's find a ride, and get to the Captain."

Cortana: "No, that'll take too long."

Master Chief: "You have a better idea?"

Cortana: "There's a teleportation grid that runs throughout Halo. That's how the Monitor moves about so quickly. I learned how to tap into the grid when I was in the Control Center. Unfortunately, each jump requires a rather consequential expenditure of energy."

Master Chief: "Something tells me I'm not gonna like this."

Cortana: "But I'm pretty sure I can take the needed energy from your suit without permanently damaging your shields. Needless to say, I think we should only try this once."

Master Chief: "Do it."

{Master Chief is teleported away.}

Easy Walkthrough (Part 1)
Welcome back to Halo central. This level in appearance will be like Assault on the Control Room backwards, with a few differences, give or take. The downsides are that you won’t have any Marines to assist you this time, the Sentinels have betrayed you, and you don’t get a Scorpion to blow the crap out of your enemies. But fortunately, the Covenant won’t just be concentrating on you. The Flood and Sentinels will try their best to give them a very hard time, and you can flank them. Also, you once again have access to the Banshee, this time you can use it a lot more. You also won’t have so much trouble to get ammo if you’re short, since the Flood carry every kind there is.

Okay, enough talking. Let’s begin. As soon as the level starts, move forwards so you’re behind a glass panel where the Sentinels can’t hit you. When you’re ready, step out of cover, and aim your plasma pistol at one of them. Firing three to five shots (providing they’re direct hits) should drop them. Do the same with the other three. If you can’t hit them, overcharge the shot and fire. If you aim squarely at them, it should lock on, and destroy them immediately. It’s easier this way, but it also depletes unnecessary ammo. Take a breather and prepare for the real action.

Walk over to the door switch and open it. It will open. A group of Grunts and an Elite will charge you. Hello boys, long time no see. Sentinels will pop out of the walls and interrupt them. For some reason, the Covenant insist on having their weapons have superior range rather than power, but they are good for pot shots, and this time it will work to your advantage. Use your plasma pistol to take down the Elite’s shields, and keep firing until he’s dead. Another one will show up with a Jackal. Kill them, and the fight will be even. When it’s almost over, move up, using the cover on the walls. Kill the stragglers, and switch your plasma pistol for a new one, or maybe a Needler if you’re peckish. Collect two Plasma Grenades, walk down the hall, and open the first door. Move to the second switch, and open it. Take cover behind a plasma shield, and crouch. When the doors open, your enemies strangely will not see you. Jump out and headshot the Grunts (you can do that in Halo: Combat Evolved) and Jackals. When the Elite shows up, switch to your shotgun and fire at his upper body at close or point-blank range. It should be fatal.

Walk to the edge of the platform. Again, pick off the Grunts and Jackals first, and if an Elite gets too close, stick him, or put an 8 gauge in his head. When it’s clear, walk down the ramps. Some Grunts, and Elite and a Jackal will be waiting for you. Throw a frag into the group and wait for the screams to subside. If there are any survivors, kill them. The next group will be Jackals and Elites. Use your plasma pistol punch to kill the Jackals, and kill the Elites with the Shotgun. Walk across, and a few terrified Grunts will be there. Headshot them, and move down. More Grunts, plus an Elite. Stick the Elite, and most of the Grunts will die. Kill whoever’s left.

Now, Cortana tells you to steal a Banshee from the Covenant. It won’t be easy. There are heavy forces, including a Zealot with strong energy shields and Plasma Rifle he fires rapidly enough to kill you if you’re not careful. And there’s the Wraith. You’ll need rapid fire and heavy weapons. Switch your Shotgun for the rocket launcher you’ll find at the group of Flood. Make sure to take ammo. For small groups, use the energy weapon; occasionally “throw in” a grenade. For larger groups, use the rockets. Save two, and use them on the Wraith. Pick up the remaining rocket ammo, and take your shotgun back. Go over to a Banshee. If this is your first time flying it, follow the instructions, and try a bit of flying. The move up to the nav point. You will see a platform, and a door will open with enemies coming out. Fire the Banshee’s plasma cannons and fuel rod to kill them, it shouldn’t be too hard. Touch down, and go in.

Ouch, that looks bright, white-hot, and powerful. And you have to walk into it. Go on, it won’t bite. When you’ve done that, take cover, because Sentinels will show up. When your shields recharged, run for it.

There’s a new Banshee waiting for you. Get in, and fly to that icy bridge. Covenant will come out, and target the Grunts armed with the Fuel Rods first, because they will most likely pulverize you if you don’t. Watch out, the guns will explode after you killed the owner. When everyone’s dead, go through that door Cortana indicated. I bet you’re jumpy, expecting to run into the Flood any minute. You will, but not yet. Deal with the Grunt marching outside the door, and take his pistol. Drop your launcher; you won’t need it right now. There’s a group of Elites, Grunts, and Jackals. The energy weapon should take care of them. You can even use the noob combo if you wish. Take your launcher back when you’re finished.

Go down the ramp with the glow (throughout the game you have to go through doors and passages with arrows pointing in the opposite direction of your destination, which were there since Assault on the Control Room), where there are two Jackals. Some simple mêlées will do, and proceed down the strangely empty hall. Halfway down the hall, you will encounter enemies, still Covenant. Stick the Elite, and the explosion will cause many casualties. Beat down whoever’s left. Move on.

At this point, the Flood will begin to show up. Take out your rocket launcher, and when you see a couple of them running across the hall, fire. You should be just about out of ammo, so take its Assault Rifle. Ah, this looks familiar. Grab some ammo for both weapons off to your right. Kill the Flood first, and then deal with the Covenant. It should be a lot easier now that you have an MA5B. When you get to the door you have to go through, more Flood will appear. Use your Shotgun for these guys.

Oh shit, the bridge. I hate this part. Not only are there enormous groups of enemies, but there are Flood lurking on the opposite bridge, where you can’t reach them. They leap over when they want to, which I find really annoying. Kill the Jackals close to you, and toss some grenades across the span to buy some time. Move up; take down any enemies you see. Use your Assault Rifle to shoot the Elites, but keep your distance. There’s a energy sword-wielding Zealot fighting with - or rather, destroying - the Flood, and you don’t want to mess with him. Stick him when he’s not looking, and run like hell. Don’t wait for more Flood to arrive.

Normal Walkthrough
Done by Asmodeus

This level does take you back through the same terrain as Assault on the Control Room, but wait a second before sticking that grenade to your head. You get to fly over it! Well, ok, a little of it. This is still a really long level. Get comfortable.

Part 01: Two Betrayals
You are immediately be set upon by four Sentinels. Run and take cover behind the transparent shielding. Get out your Plasma Pistol and take out each Sentinel with a charged shot. Plasma weapons work great on these guys. Run up and hit the switch on the right to open the door.

Part 02: The Gun Pointed at the Head of the Universe
This next battle is a nasty one. The Covenant will easily take out these Sentinels if you don't intercede, and you don't want that. You want them to kill each other off down to the last man, so toss a Fragmentation Grenade or two into the middle of the Covenant group as soon as you see them. This will be a very long throw, but you just got a checkpoint, so you can restart if your aim is way off. Hopefully this will not only kill off most of the Grunts, but also blow their weapons your way. After the initial Elite and Grunts, a second group consisting of an Elite and two Jackals will come out to fight. Try to work it so the Elites get killed before the Sentinels. You can fire off a few charged plasma bolts, but don't get too close. If you do, some of the Sentinels will turn their attention towards you. Once they do, you'll have to take them out quickly. Try not to let that happen.

Once the Sentinels are scrap, pick up a Needler if one got blasted your way and use it on any remaining Elites. Use charged shots from your Plasma Pistol if you don't have a Needler. Run right up to the Elites as you're sending them charged shots then switch to your Shotgun and blast them. Finish off the Jackals with more charged plasma shots. That's a lot of plasma to go through, so pick up another Plasma Pistol whenever you can. Pressing yourself up against either wall and crouching will provide cover, but not very much. So you'll have to do most of this battle without recharging. Once everything is dead, put your Shotgun in a very safe place and grab a Needler, Plasma Pistol, and all the grenades you can carry.

Next comes another tough battle. Open the first door and move through. Immediately after opening the next big door that leads outside, retreat. A bunch of Grunts will come wandering in after you and you want to keep your distance. Take these guys out with charged plasma shots. Back up to the site of the previous battle to recharge. Keep blasting until the Grunts are dead. Now you have two Jackals and two Elites to deal with. Get as close as you dare then look for an open enemy. If it's an Elite, fire off a magazine of needles towards him. If it's a Jackal, fire off a charged plasma shot. Use the stationary shields if you're feeling courageous, but be careful of Jackals dropping them with charged shots. They do that sometimes. Remember; enemies cannot see you crouching behind a stationary shield even though you can see them so stealth is an option here. Go back and grab more needles and a fresh Plasma Pistol when you're running low. Repeat until you've taken out nearly the entire Covenant. That last bad guy or two can be annoying to finish off, so don't worry about it. Find a decent Plasma Pistol and grab your Shotgun. Run up one last time and send off a few charged plasma shots and a grenade or two. Whoever is left will probably run for cover so follow up with your Shotgun at close range, blasting Elites and bonking Jackals.

Now you can relax. No more tough battles for a while. Don't scavenge around here yet. I've got a plan. Toss your Shotgun in a memorable spot and grab a Plasma Rifle. Keep your old Plasma Pistol as well. Walk up the ramp and into the tower. At the end of the path are a health pack, a Pistol, and a Sniper Rifle. Toss both your weapons and grab these goodies. Remember where this ammo stash is. You'll be flying back up here later. Head down to the site of the last battle. You should have a nice array of weapons by now. The Sniper Rifle doesn't have much ammo, so you'll want to save that for later. The Pistol and Shotgun are your two staples. Always keep these around. And you have a pile of Plasma Pistols and Needlers that are good to use up on enemies at a distance.

Since that's what you're facing next, grab a Needler but keep your Pistol. Move off to the right (assuming you're facing out towards the canyon) and peek over the edge. You'll see several Covenant patrolling down below. Burn through all the nearby needles to soften them up then pick up a Plasma Pistol and toss the Needler. Peek over the edge just far enough to fire off a charged plasma shot at an enemy then quickly switch to your Pistol and zoom in. If the shot hits, follow up with the Pistol. Keep doing this until either all the guys below you are dead or you run out of needles and Plasma Pistols. Grab your Pistol and Shotgun and locate your Sniper Rifle. Continually switch it out with one of your weapons to toss it down to the level below. Follow it down and put your Shotgun in the face of anybody who was giving you trouble before.

Now you have a large amount of space to work with and can look down on the enemies below you. Needlers are once again very useful since you can rain needles on enemies who can't find any cover. And if the Covenant aren't paying attention you can often drop Plasma Grenades on them as well. Look off the left side first. There will be a couple of Elites and a Jackal here. You definitely want to take these guys out with needles and grenades if you can. Head back to the right when you're done and take a look at the Covenant down below. A couple of Elites, a Jackal, and a Grunt. Snipe the Grunt and Jackal with your Pistol or charged Plasma Pistol shots. Head down the path and get the attention of the Elites then run back up top and move around behind them. Peer over the edge and toss a grenade onto them or let loose with a magazine of needles.

Go back up and retrieve your Shotgun and Sniper Rifle. If you want to plan ahead, you can toss your Sniper Rifle down to the walkway below so you don't have to go as far to retrieve it later. Or you can even take it with you, constantly switching it out with another one of your weapons.

You should have already taken out these next guys from above, but if there's anyone left just use the chunks of debris as cover. Sneak up then run out and pump a few Shotgun shells into them.

Moving along you'll see two Grunts at the other end of the upcoming tunnel. Zoom in and blow their heads off. Move up to where they were standing and take out the Jackal nearby with a few shots to his vulnerable spots with your Pistol. Toss your Shotgun (remember where it is of course) and pick up the Needlers dropped by the two Grunts. Stay out of the range of the two Elites ahead and unload your Needler on them. A few magazines later they should be toast. Now you should go retrieve your Sniper Rifle. Pick it up; toss your Needler and head back down to the bottom floor of the pyramid. Part way down the last ramp you will get a checkpoint, so take a moment before you trigger it to make sure you're set. Run back to the ammo stash if you're running low on rounds for your Pistol or Shotgun. And if you want you can move your Shotgun to the top of the ramp to make it more accessible later. Once you're ready, move ahead.

After the checkpoint, get your Sniper Rifle out and zoom in on the Banshee ahead of you. As you move past the piece of debris the next group of Covenant will appear. An Elite will come running out from behind the Banshee, so put a couple of sniper rounds through him when you see him. It is possible to kill the Elite with your Pistol on Legendary but it requires all rounds to hit him. Switch back to your Pistol and look for Grunts and Jackals to snipe at. The Wraith will start lobbing mortars soon, so move into the shelter of the tunnel once things get too hot. From the tunnel you can peek out both sides and snipe most of the Covenant in the area. Use your Pistol to clear out the Grunts and Jackals, and then switch to your Sniper Rifle for the Elites. Be patient here as sniping the Gold Zealot Elite will save you a lot of grief. Kill the Zealot and waste as many Elites as possible. Once you've emptied your Sniper Rifle and gone through a few Pistol magazines, there should only be a few Elites left. Now it's time to put the smack down on that Wraith. You've probably noticed that Rocket Launcher by now. Go toss your rifle and pick it up along with an extra magazine of rockets to top it off. Be careful not to grab the health pack unless you really need it. Put those rockets to good use. Move through the tunnel and target the Wraith. Wait until it stops moving then fire. Keep watching for a moment to confirm you actually hit it then duck back into the tunnel away from the mortar shells. Three rockets will finish it off, but I recommend only hitting it twice. Instead of that last rocket, empty a couple of magazines of Pistol ammo into the tank. You will be filling up on Pistol ammo soon, so this saves you a rocket. Once the Wraith is scrap you can go back and grab the extra magazine of rockets. If you didn't miss, you should now have a full rocket launcher. Retrieve your Shotgun and switch it out for your Rocket Launcher.

Now we have to deal with the last few Elites. Make sure there are only Elites left. Snipe any remaining Jackals or Grunts. The Elites have all probably migrated to the side of the pyramid where the Wraith was and where you probably are now. If not, harass them until they're all on that side. Now quickly run into the tunnel and drop down on the far side. Run up to the left wall and turn right so you're facing the back of the canyon. Run along the wall and hope the Elites don't see you. Once you've run all the way to the ice flow, turn around and head to the other side of the pyramid. Run up behind the Banshee, hop in, and fly away from those Elites as fast as your anti-grav pods will carry you. Hover over them at a safe height and pound them into the dirt with your Fuel Rod Gun.

Once you've bombed them all into submission, head back up to the top of the pyramid to grab more Pistol and Shotgun ammo. You should be carrying both of these weapons. Fly up to the top and fill up on goodies.

Now you can head towards the nav point. Fly in from above. As you approach you'll see the door open for an Elite and two Grunts. Aim for the Elite and nail him with the Fuel Rod Gun. Finish him off with the plasma guns, but be careful. You want his Plasma Rifle, so notice where it lands. If the Grunts haven't retreated, take them out with the plasma guns as well. Land and switch out your Pistol for that Plasma Rifle. If you can't find it, grab one or both of the Needlers. Follow the corridor along until you come to the pulse generator. Hop into the middle of the beam to destroy it then run immediately to the back of the room. That's right, the side away from the door. A whole mess of Sentinels will move into the room. Peek in and use your Plasma Rifle or Needler on them. Half a magazine of needles per Sentinel is plenty. Duck back to recharge often. These guys can wear down your shields fast. Your Covenant weapon should take them out pretty easily. If you run out of ammo, just move around the outside of the room and leave.

Part 03: Breaking Stuff to Look Tough
Head back out to your Banshee. As you step out onto the platform look to your right. Hey, it's another Banshee. How did that one get up here? Take it since it is undamaged and fly down to the land bridge. You have two groups of Covenant to worry about here, one from each side of the bridge. And they have a new toy. Most of these Grunts are carrying Fuel Rod Guns. Take these guys out with some Fuel Rods of your own. Hover and bomb as usual until there are just a couple of guys left. You want to have at least one of their plasma weapons land on the bridge when they die, so don't blow them away with Fuel Rods. Try running into them or hosing them down with plasma. If you take a lot of damage, fly back up and grab your old Banshee. It probably hasn't taken much of a beating. Once you've cleared off the bridge, land on it and switch out one of your weapons for any old Covenant weapon lying around. This is why you needed to make sure one landed here. Now fly back down to where you left your Rocket Launcher and pick it up, tossing your Covenant weapon by the wayside. Fly back up to the land bridge and get out. Now you have a full Pistol, full Shotgun, and possibly a full Rocket Launcher all here on the bridge with you. Sweet. If you're feeling confident, don't bother moving the Rocket Launcher along with you. If you can't stand the thought of leaving a Rocket Launcher behind, move it into the tunnels with you. You know the routine. Keep switching it out with another weapon as you walk forward.

The previously mentioned tactic doesn't work very well on Legendary. The Grunt with a Fuel Rod Gun is much more accurate, and the Elites can hose down your Banshee very quickly. What you need to do is, if you didn't take the Sniper Rifle from the tower earlier, go back and get it, then get the Banshee up onto one of those semicircular beams above the blast door, and snipe all the enemies. It's an extreme distance, but that's what the sniper is for. Target the Elites first (remember to aim for the head), then the Grunt with the Fuel Rod Gun, and if you have any ammo left, kill the Jackal. Once they are all dead, go back to where you got the sniper and get your other weapon back. [Added by Azure-nightmare]

Move ahead through the corridor and you'll get a checkpoint. Keep going into the room ahead and try to bonk the lone Grunt before he gets into the interior of the room. There are a lot of Covenant in here with you, and this battle can be a real pain. Fortunately you have a Rocket Launcher! Unload on these guys. After launching a rocket, switch to your other weapon (doesn't matter whether it's the Shotgun or Pistol) to finish off anyone damaged by the explosion. By the time you're out of rockets there should be far fewer Covenant in the area. The remaining enemies can be handled as usual. Bust out all the windows and use them to sneak around. Snipe Grunts and Jackals with your Pistol. Use charged shots on annoying Jackals or Elites. Stick grenades to any Elites who can't see you. Once there are only Elites left, fill them full of needles or move in close and blast them with your Shotgun.

Once the room is clear, find a good Plasma Pistol, keep your human Pistol, and drop your Shotgun in a safe spot. The ramp ahead leads down to an area with three Jackals. Use charged shots to take them out. One will probably retreat to the next room. Let him go for now.

Head back to the site of the previous battle and fill up a Needler, dropping your Plasma Pistol. You can move your Shotgun along with you as well since we'll need it eventually. Move down the ramp and past the area where you just axed a couple of Jackals. The next group of Covenant will appear at the end of this corridor, but they won't show up until you've moved part of the way down. If one of those Jackals retreated here, take him out now with your Pistol. Now move forward until the Covenant shows up. Back up and fill the hall with needles. Fire off a magazine on one side of the columns, move over, reload, and then fire off a magazine on the other side. This should take care of most of the Grunts and possibly the Elites. Once you've emptied the Needler, go back and switch it out for your Shotgun. Head back to the battle and snipe any leftover Grunts with your Pistol. The Elites can be taken out a number of ways. You can rush them with your Shotgun or you can peer around the columns and stick grenades to them. Either way works. Once they're dead, you can move into the next room where you will get a checkpoint.

Stay up against the right wall and move to the base of the ramp into the next room. Stay out of sight while the battle rages on ahead. Once it dies down, move up to the top of the ramp, but not all the way into the room yet. Walk in just a step and look to your left. Over the little wall, you should see a couple of Elites that survived the battle. They will notice you and start shooting. Don't retreat. That little wall that runs around the room will protect you. They aim for your body, not your head. While they're firing, take careful aim and stick a Plasma Grenade to one of them. If that doesn't take them all out, throw another grenade or just rush in with your Shotgun to finish the job.

Several Jackals and an Elite Commander will be coming around the corner soon, so back up. Stay at the top of the ramp until you see them. Toss a couple of Frag Grenades towards the Jackals and retreat down the ramp. From down here, you can take out the rest of these guys. Snipe the Jackals with your Pistol, and if the Elite Commander comes down after you, stand your ground and blast him with your Shotgun a few times at point blank range. Some of the Jackals may come down after you as well, but as long as you're on the right side of the doorway, they'll have to expose their unshielded side to you as they walk, which makes them fodder for your Shotgun. If the Commander hangs back, wait until the Jackals are all toast, then rush him with the Shotgun or stick a grenade to him just like the previous Elites.

Ok, now that those guys are taken care of, look to your right. There's a Shotgun full of ammo, several Frag Grenades and two health packs. Go fill up and look through the slits into the other side of the room. You don't really want to waste Pistol ammo on something this easy, so grab a Plasma Rifle or something. Peek through and hose down anybody you can see. Be careful of the window. You should probably stay crouched. Just keep firing until all the Grunts and Jackals are dead. Go back and grab another plasma weapon if you need to. Be patient and eventually killing one of the last Grunts will trigger a group of Flood to rush in behind the Covenant. Once this happens, grab your Pistol back and get your Shotgun ready. These guys should take out the rest of the Covenant for you and should be easy for you to kill. Just move through the room and take them all down with your Shotgun. There will also be some carriers towards the back, so don't let them sneak up on you. Search carefully and you'll find some valuable Pistol ammo amongst the bodies. Be sure to grab it. And head back to grab a health pack and more Shotgun ammo if you need to.

Moving along you'll come to another battle between Flood and Covenant, this time out on the bridge. Run out the door, take a right around the support, walk up behind a Jackal and blast him with your Shotgun. Blast another if you can. Retreat, get your Pistol out and snipe the rest of the Jackals. After the entire nearby Covenant are either dead or retreating, follow them down the bridge. Snipe any Flood that are lingering around on the other bridge, but not if they're also firing on Covenant. At some point the Elite Commander will come to kill you. Back up and blast him a few times with the Shotgun. He should go down pretty easily. Peek around one of the walls in the middle of the bridge and toss a Plasma Grenade onto an Elite. There should be several running around ahead. Keep sticking grenades to them until they retreat. Move ahead to their previous position and keep an eye out on the other bridge. Several Flood will jump over soon. Back up when you see them and hope they all go after the Covenant. Shotgun any who come after you. If there are any Jackals left, zoom in and snipe them before proceeding. While the Elites are still recovering from the Flood assault, rush in and spread buckshot liberally around the area. If the Covenant are all-dead, so much the better. The rest of the bridge should be cake. Just keep your Shotgun at the ready and look out for Flood jumping over from the other bridge.

The next room contains a huge amount of Flood, but is relatively easy. Run in and head straight into the interior of the room. Fire off a few Shotgun shells into the Flood at the other end of the room then retreat. When you reach the door you just came out of, turn around and toss a grenade at the oncoming wave of bad guys then keep on retreating into the hallway. Back up so the Flood have to come around a corner to get to you. As they come around blast each one with your Shotgun. Toss grenades as necessary and keep backing up if you get overwhelmed. There will inevitably be some stragglers, so move back up and use the same tactics until they've all been taken care of. There are still three groups of Flood to deal with in this room. One on the left, one in the middle, and one on the right. Let's take the one in the middle first, since they sometimes will interfere with your other fights. Move into the interior of the room and look up the ramp. These guys are armed with Shotguns and Pistols, so be careful. Snipe with your Pistol or move up the ramp and use your Shotgun. Grab all the ammo they dropped. Ok, now head back the way you came to the exterior of the room. Assuming you're facing the interior, we're now headed left. This group is at the far end of the room, almost at the door. Toss a Plasma Grenade right into the middle of them. They aren't that bright, so they should just stare at it until it goes off. Any survivors will probably come after you, so Shotgun them. Now it's back around the way you came only this time we're headed right. Walk up and just blow these next Flood away. They aren't that well armed. Standing in the doorway out of this area are two Elites. They will have a hell of a fight on their hands soon. If it hasn't started already, move towards the doorway until it does. It should be a pretty fair fight until a Flood with a rocket launcher shows up at the far end of the corridor. Peek around far enough to watch the battle and snipe this guy as soon as possible. If you see him fire a rocket, retreat. Peek back around and make sure this guy goes down. Take out any survivors as usual. If you're a big fan of the rocket launcher, you can pick this one up for now, but it's not very useful. I usually just leave it.

Cruising along you'll come into another room with a smattering of Flood. Show them the business end of your 8-gauge then move towards the interior of the room. Hiding in the first vent on the right is an infected human, so snipe him before he makes a nuisance of himself. There is also a Flood on the second ledge on the left. He moves between the interior and exterior of the room, so you may have to wait for him. Take him out with your pistol when he shows up. Move towards the centre of the room and keep your shotgun trained on the second vent on the right. You will trigger an explosion. A few Flood will come out of the vent and a ton of infection forms will drop down. Quickly blast the combat forms then retreat before the little guys overcome you. Keep retreating and managing the little guys so they don't get through your shield. Once they're all popped, move back into the centre of the room, blasting anybody on the way. Once you're in the middle, the rest of the infection forms will suicide on you. There are a few Flood left in the exterior of the room near the exit. Most of them have pistols, so you can use up your pistol ammo on them. Once you've sniped all of them, move in to pick up their ammo. You can also grab the health pack lying by the door. There are a great amount infection Flood waiting in the hallway ahead, so take them all out before moving on.

The next battle takes you back out onto the double bridge for the last time. There are two Banshees flying around in the air and a bunch of Flood on the bridge with you. Wait around in the hallway for a bit and the Banshees will take out most of the Flood for you. This is a good time to trim your toenails or make a sandwich. Once you're tired of waiting, run out and get the attention of the nearby Flood. Duck back into the hallway you came from and shotgun each of them as they come after you. That should clear out a bit of space on the bridge. Enough for you to take out the Banshees. Stay near cover and gun them down with your pistol. These guys will often fly in close, so blast them with your shotgun if you get a chance. After several dozen pistol rounds, they should be grounded for good. Move out onto the bridge now and switch to your shotgun. Several Flood will appear, but it's nothing you can't handle. Zoom in with your pistol and look down the length of the bridge. Snipe any Flood that wanders into your crosshairs. A few of these guys have rocket launchers, so you want to take them out from as far away as possible. About three quarters of the way along the bridge, a big group of infection Flood will appear in front of you. Ditch one of your weapons, pick up anything handy and blast these guys. If you can't find another weapon to use on these guys, just run around and keep recharging like you usually do. Grab your old weapon once you're done. The rest of the bridge should be pretty much clear. Whatever the Banshees missed, you probably sniped already. There are probably several rocket launchers lying around, but unfortunately these are just as useless as the last one. Just leave them.

The next room has a pretty pathetic group of Flood for you to battle. No matter what you do the first group of infection forms won't budge, so have some fun with them. Step into the middle of the room to trigger the Flood. Just a few combat forms will come out to play, along with some carriers. Take everybody out and deal with the infection forms. Move through the room and around to the exit. There are a few combat forms blocking the way. Toss a grenade, shotgun, pistol. Take your pick.

Head down the elevator and move through the door as soon as you reach the bottom. You don't want to get caught in the elevator shaft with all those infection forms. This next room has an equally unchallenging group of Flood. I guess it's nice to get a break after those previous battles. At the end of the hall, two infected marines will drop down in front of you. You know what to do. The rest of this room consists of several more infected marines that have found their way into some pretty peculiar places. Be sure to check all around you as you move through the room. Not much else to see here. Move along.

Finally, you get some space to move around. Run out the door and head for the Ghost. On your way try to take out the elite and grunt with repeated shotgun blasts. Don't worry about them too much though. Hop in the Ghost and head to the right. There's another Ghost back here to take care of first. Keep circling him and blasting him with your plasma cannons. As long as you keep moving, neither he nor the Banshee flying overhead will do much damage. Once the other Ghost is toast, head down into the ditch underneath the big pipe thingies. There's another Ghost down here, two health packs, a rocket launcher, a magazine of rockets to top it off, some shotgun ammo, and pistol ammo. Woo ha! Grab a health pack if you're hurting, but don't grab anything else yet. You should still have plenty of pistol ammo. Use it on that Banshee. You may have to leave the safety of the ditch to get a good shot, but be ready to run for cover if the Banshee gets a good angle on you. Gun it down then run back to the tunnel and switch out your shotgun for that rocket launcher. Grab the extra rockets, but not the pistol ammo. Hop in your old Ghost and fly up out of the ditch towards the Covenant. You're probably supposed to stop up here and take these Covenant out from the top of the ramp. I have a different plan. Fly straight through the middle of them. Head through the hail of plasma fire, hope the Wraith doesn't get off a lucky shot, and fly off the cliff into the area below and behind them. You could just leave now and forget these guys, but it's easy as pie to take them out from here. Head up the switchback and peer over the edge at the Wraith. He can't hit you from there. He'll just keep pounding the dirt in front of you. And the other Covenant are far enough away to not be much of a problem. Shoulder your rocket launcher and send four rockets to end this Wraith's miserable existence. Why does this one take four and the last one took three? Who knows? Take out any occupied Shades, the elite (if you didn't get him before), and jackals with more rockets and snipe the remaining jackals and grunts with your pistol. All too easy. Head back to the ammo stash in the ditch and fill up on everything. Toss the rocket launcher and grab your shotgun. You should be full of ammo, health, and probably grenades when you leave here. Grab the Ghost with the least damage and head out.

Cruise down the switchback and into the tunnel. Squeeze your Ghost out the other side and move ahead. Two jackals are wandering around nearby, so stop for a moment to hose them down with your plasma cannons. Ahead, you will come to an overturned warthog and another ammo stash. Unfortunately it's not very useful since you should be full already. Fly up the winding path in your Ghost. When you reach the top move ahead a bit and blast the four grunts up here. Once they've all been sent to an early grave, you have a couple of choices. You can take on the upcoming battle in either your Ghost or that warthog. And you can follow two different strategies. The first is really risky and will get you killed several times, but will probably save you time in the long run. The other is a little slower and more methodical. Read ahead and pick whichever one sounds like the most fun.

Ok, first the balls-out strategy. Take your vehicle of choice and drive/fly in towards the left of the tower and head straight for one of the Banshees. Take a moment to either run over or gun down the three elites, then hop out, get in a Banshee, and fly the hell out of there. Once you're in the air, you'll end up dogfighting up to four other Banshees. Enjoy the Banshee on Banshee action. This is the only dogfighting in the game other than a brief bit on Assault on the Control Room. They're fairly easy to take down. You just have to figure out where they are. Once you have control of the skies, you can hover and bomb anyone down below. Obviously there's the Wraith to deal with along with any elites you didn't kill when you picked up your ride. There is also a gaggle of grunts with a Shade on a hill. And lastly there's a pair of hunters on the other side of the pillar. Once you're done go back down, land near where the grunts were, and skip the next paragraph.

If you want to take the more methodical approach, drive your vehicle of choice into the next area. Head in on the right side of the pillar, towards the hunters. Running them over can be hard in either vehicle for different reasons, so I usually get out and take them out at close range with a few pistol shots. You know the routine. Walk up and when they charge run backwards and shoot them in the gut, or sidestep and shoot them in the back. On the other hand, you could hop in the chaingun, kill one easily, hop out, avoid a fuel rod shot, and then go up close. There are two Banshees flying around overhead and one of them has probably noticed you by now. If you're in the Ghost, you're guns won't aim that high. You'll have to stay pretty far away and angle up while dodging most of their shots. Or you can get out in a safe spot and take them down with your pistol. Pistol ammo is about to get scarce, so if you do gun them down, I highly suggest heading back to the previous ammo stash where the warthog was to fill up. If you're in the warthog, drive back out onto the ice near where you came into this area. Get out and hop in the gunner's seat. For some reason, these guys don't seem very accurate with their fuel rod guns, so you're actually fairly safe in your warthog. Plus you get these great shots of Banshees exploding in midair and sliding on the ice into your hog, which is cool. Take out both Banshees then head back around to the right of the pillar. Keep moving around until you can see the Wraith ahead. If you're in the Ghost, you'll probably need to move a little closer. Keep pouring on the plasma while dodging the mortar shells and eventually you'll bring the Wraith down. If you're in the hog, get as far away from the Wraith as possible while still being able to see it. Get in the gunner's seat and start burning through the rounds. At this range, the Wraith will have a bit of trouble hitting you, but if you see a mortar that looks like it's going to hit, hop out of the warthog and run away. Get back in your warthog after it hits, drive to another spot, then get out and continue with the chaingun until he blows. Once you're done with the Wraith, keep moving around the pillar and look for a group of grunts on the hill ahead. They have a Shade at the top too. Use either your plasma cannons or chaingun to take them all out long range. Concentrate your fire on the Shade and use short bursts to keep your accuracy up. Once all the grunts are dead, move up to their position and get out. They left a bunch of needlers on the ground for you, so toss one of your weapons for a moment and pick one up. There are three elites down below, so peer over the edge and go crazy with the needles. They don't have much cover since you're basically above them, so they don't stand a chance. Once they're taken care of, toss the needler and get your old weapon back.

Ok, regardless of which strategy you used, you're probably in need of a health pack. There's one inside the pillar. There should be an unlocked door near the hill the Shade was on. Go in and get healthy. Head back out and pick up your well-deserved Banshee. If you've already been flying around, be sure to pick the undamaged one.

Fly way high up in the air away from the pillar. Another couple of Banshees will come out to play if you haven't fought them yet. Stay away from the troops on the top of the pillar and hose these guys down with your plasma cannons. Fly back up high over the top of the pillar. There are several grunts and an elite commander down there. Some of the grunts have fuel rod guns and some are in Shades, so be sure to stay near the maximum range of your fuel rod gun. Bomb the grunts into oblivion then drop down a little closer to take out the elite commander. Now you can head back up and bomb the guys at your next nav point. There is a jackal, an elite, and a grunt with a fuel rod gun. Land after you blow them all away and head into the hall.

Run into the room ahead. There is a whole mess of Flood battling only one or two Sentinels in here, so the battle will be over fast. Peek into the interior of the room and toss a grenade or two towards the bulk of them. Be careful. Some of these guys have rocket launchers. Retreat into the hall and shotgun anybody who follows you. Usually you'll get stuck with a checkpoint right about now. This is a bit annoying since you haven't cleared out the room yet, but that's okay. At least you get one. Go back in and finish clearing out the room Grab a rocket launcher and gather up the spare rockets. Also be sure to knock out any windows that are still intact. Continually switch out your rocket launcher for either your pistol or shotgun to move it to one of the vents. Look up at the vent and keep switching out your weapons until you can get one of them to land up inside the vent. Back up and jump up into the vent. Now switch weapons some more to move your rocket launcher towards the back of the tunnel. Thanks to SpudNYC for suggesting tossing a rocket launcher up here. Good idea! Hop back down out of the tunnel. Practice jumping back into it a few times. It's a tough jump. It may help to tap crouch at the height of your jump. It gives you an extra bit of air. Some people call this double jumping or crouch jumping.

Anyway, once you're ready get your shotgun out and jump into the pulse generator. Immediately run up to the vent with the rocket launcher and blast any Flood who have spawned there. Jump up into the tunnel and shotgun anybody who follows you up here. Switch out your pistol for the rocket launcher. Peek out of the tunnel and take a look around. You can take out nearly the entire Flood from here. Look out towards one of the exits to the exterior of the room. Most of the Flood will be out there. Fire off a few shotgun shells towards the exit to get their attention. A big pile of Flood will usually come to investigate. Watch for them on your motion tracker. Fire off a rocket into the group and retreat into the tunnel. Peek out and finish off anybody in the interior of the room then do it all over again. Shotgun to get their attention then blast them with a rocket you can also use this same trick on any nearby windows you can see through, though it's a little more likely to get you blown up. Grenades work well when using the windows since you can toss them and retreat before the Flood show up. Once you've run out of rockets, snipe the rest with your pistol or use grenades. When you're left with just a few blips on your motion tracker, you can hop down and take the rest out with your shotgun as usual. Just pray that none of the one's left have rocket launchers. Once you're through here, head back out and pick up the shiny new Banshee the level designer left for you on the right.

Part 04: The Tunnels Below
Fly down into the tunnel. Stay near the ceiling at the tunnel entrance. This a nice battle to watch, but you don't want to get too close. The Shade might start firing on you, so be ready to drop to the ground if necessary. You could just nuke it with a fuel rod, but the Covenant need the firepower. You want them to win this battle. The Flood have rocket launchers and those are bad. Wait around for a long time until the fighting stops. If the Covenant win, they tend to stay put and let you bomb them into oblivion. If the Flood win, they tend to run up and shoot you with a rocket. So if you see a Flood coming towards you, try to fly back out of the tunnel with some evasive manoeuvres. Turn around and bomb him once you have some breathing room.

Once you've taken out the winner from the previous battle, fly down and look for a rocket launcher. Switch out your shotgun for it. If you can't find one, well, that's ok. Run down towards the bottom of the tunnel and look for a couple of Flood standing on a rock where the floor turns from dirt to metal. Launch a rocket at them or just snipe them with your pistol. One of these guys should definitely have a rocket launcher, so grab it now. Keep moving ahead past the Ghost and hug the left wall. Zoom in with your rocket launcher and look around the corner to the right. Inch forward until you see an arm or leg of a Flood around the corner. Launch a rocket at him then back up. Launch another rocket towards the corner to blow up any survivors. Get your pistol out and snipe anybody that survives the rocket blasts. Head up and get in the Ghost. Skim over to where you left your shotgun and switch it out with your rocket launcher.

Cruise on down the tunnel until you come to the locked door. Hop out, hit the switch, hop back in. Wait around for any Flood to stick their head through the door then blow it off. Once you're pretty sure they're all dead, get out of the Ghost and walk through the broken door. Shotgun anybody hiding behind the door then move off onto the bridge to the right.

Keep moving until a mass of infection forms flow out onto the bridge in front of you. Keep your shotgun pointed at them and retreat. Several unarmed combat forms will be coming in behind them. Melee the little guys until the combat forms get close then waste everybody with your shotgun. Keep backing up all the way to the broken door if necessary. Move back up after you're done with them. Several more combat forms will spawn at the end of the bridge. When they do, fire off a few shotgun shells towards them while you retreat. A couple of these guys have rocket launchers, so sidestep back and forth a bit as you run back. Once you're far enough away, switch to sniping these guys with your pistol. If one starts to charge you, switch to your shotgun and blast him when he gets close. You could just keep on him with your pistol, but switching to your shotgun will save you a few rounds. Take everyone down then move cautiously ahead. Sometimes these guys like to hide around corners, so keep your shotgun up and check all around. There are two health packs here and we're about to leave, so grab one now even if you're just scratched. Move to the big door and hit the switch to open it. Head through and follow the big tunnel.

Part 05: Final Run
Head up the ramp into the open. There is a small group of Flood waiting around on the right. Toss a frag grenade right into the middle of them then rush in and finish off the rest with your shotgun. Look back towards the battle and locate the Banshee. Sometimes he comes straight for you, so duck under the trees ahead for cover. Occasionally I've had an elite commander come gunning for me as well right about now. If you see him, keep a tree between the two of you until the last minute, then run out and blast him repeatedly with your shotgun. Now back to the Banshee. Stay near the trees for cover and shoot him down with your pistol. Be ready to switch weapons and blast him with a shotgun shell if he flies too close. Once he is grounded, move forward and peek over the snow covered hills towards the battle raging ahead. You want the Flood to win this one, so snipe anybody sitting in a Shade. Once those are unmanned, keep sniping at anything that looks like a good target. If there is a lot of Flood left, switch to sniping them. You want them to win, but by as small a margin as possible. Once the battle has been decided and only one group stands against you, you'll have to finish off the survivors. If they are Flood, they'll come after you in a big mob. Snipe with your pistol at long range aiming for any Flood with rocket launchers, then switch to your shotgun when they get close enough. Keep backing up and blasting them until they all go down for good. If they are Covenant, they won't come to you. You'll have to go to them. Snipe any grunts and jackals still wandering around first of all. There should only be a few elites left. If there are any needlers handy, use them up. Same goes for rocket launchers. Once you've run out of options, try to sneak around behind or beside them. Use whatever cover you can. Energy shields work well. When they turn their back or get close, rush out and keep pumping shotgun shells into them until you're the only thing left standing. On the Legendary setting the Flood almost always win this battle against the Covenant forces, once they are finished mopping up they will come for you. A good tactic is to fire a few rockets at the cave entrance where the Flood are coming out of to soften them up to even the battle, this will make it easier for you to pick off the survivors. It can even help to leave the Banshee flying in the air as his fuel rods often decimate large numbers of Flood at a time. Make sure to pick up rocket ammo. Get in one of the Ghosts and cruise along to the next area.

Again you will be on the fringes of a battle between the Covenant and the Flood. Move out into the open for a moment to make sure they start fighting each other then retreat back into the dark canyon you came through. Let them fight it out and gun down anyone foolish enough to come after you. Once the battle is over, swing back out into the open and use your plasma cannons to hose down anyone left alive. There are four Flood with rocket launchers waiting around on the other side of the clearing. Don't worry about them until you've taken everyone else out. Then you can hop out and snipe these guys down with your pistol. Watch for rockets. If they fire one at you, sidestep out of the way. Once they go down, look to your left. There's a big stash here. Ammo of all kinds and a health pack. Be sure to pick that up, even if you don't need it very much. You'll definitely want to grab a rocket launcher and fill it up. A good idea here is to horde as many full rocket launchers as possible to consolidate ammo supplies, if you do not pick up the fallen rocket launchers from the flood they will eventually disappear but if you pick up the weapon and drop it it will stay indefinitely. As your other weapon, I'd keep the pistol. Get back into your Ghost and head to the site of the previous battle. Your Ghost is bound to have taken a couple of hits, so pick up the undamaged one here then cruise ahead to the next battle. You'll notice there is a ledge blocking your progress. Aim yourself towards the left end of the ledge, were it meets the wall. Fly towards it and press A to lift your nose up. With a bit of work, you can get your Ghost up on top. You should get a checkpoint here as well.

Ok, the last real battle of the level. This can be amazingly long and difficult (and fun) if you try to take everyone on the traditional way. As you near the battlefield, Flood will come running from either side, but they're going to be annihilated. Only on very rare occasions will the flood win the fight as there are a few combat forms with wielding rocket launchers (I personally have seen them take out every wraith) but by no means count on them doing so. For the most part they stand no chance of taking out these Covenant for you. Hanging back and sniping will work eventually to take them out, but I have a much quicker way. Fly straight in through the middle of the erupting chaos. In between the two Wraiths are two Banshees parked at the back of the battlefield. Behind them are two boulders sticking out of the ground. We're headed around to the left side of those boulders. Feel free to shoot at anything that you want on the way, but don't dawdle too long, or you'll end up dead. Cruise around behind the rocks and get out of your Ghost. Now if you wanted to you could jump up in between the rocks, run up behind a Banshee and fly the hell out of here. Your Banshee would get shot up pretty bad, but you'd probably make it. These guys are just way too fun to kill though, so turn back towards the battle and head to your right. Look around the edge of the rock. There should be a Wraith there. He's pretty easy prey for your rocket launcher, but can definitely hit you if you stay near the edge too long. Peek out a few times and keep launching rockets until he's been destroyed. Now head back to the left side of the rocks. Peek out this side and you should see another Wraith farther away. If he's still paying attention to the Flood you can get a free shot off. Otherwise he'll just dodge the rockets. Feel free to spend some time back here launching rockets at things and sniping stuff. Watch out for several stealth elites that will appear eventually. You probably want to be gone before they show up. When you're ready, hop up between the rocks and get in a Banshee. Fly up out of firing range then turn around and look over the battlefield. There are a lot of little guys moving around down there, so start bombing. Take out the Wraith first, since it's the only thing that can hit you up here. Once it's gone, you can drop a bit lower. Continue bombing and eventually a new wave of Covenant will spawn behind the rocks where you were hiding before. This wave includes two hunters. You probably want to save them for last since they take so many hits. Keep bombing away with your fuel rod gun until you've finally taken out the last of the Covenant. Whew. Think you're done? Well, you're not. There are still up to five stealth elites wandering around the battlefield. Drop down almost to ground level. Two of them tend to wander around near the other Covenant. Don't worry about them shooting up your Banshee until you're in the red. Just drop down and be a sitting duck. When they fire, concentrate on one at a time and spray the area down with plasma. Once your Banshee is on its last leg, fly back and grab your Ghost. Fly your Ghost back out and track down the other stealth elites. As you're heading away from the battlefield, you should see a hill in the middle of the canyon. They tend to hang out on the left side of this hill, near the frozen pond. Once your Ghost is about to blow, head back and grab the final Banshee. Use it to clean up the remaining stealth elites and you will finally be done with this battle.

Alternatively take the Sniper Rifle and target only Elites, annihilate as many as you can with headshots. You have limited ammo with your Sniper so make your shots count. Then settle your sniper-targeting reticule on a Wraith and then switch to your Rocket Launcher and fire. Use this technique of rocket sniping to take out the Wraiths at extreme range. Be prepared for camo Elites to open fire at you by having your Ghost at your side at all times. Head back to the previous area to pick up rocket ammo and switch to your pistol. Pick off the rest of the Covenant forces and move in. Hunters will appear, dispatch them and take a Banshee.

Fly back to the nav point. When you get close, gain some altitude and get ready to hover over your enemies as usual. There are several Sentinels guarding the entrance to the last pulse generator. They're pretty small targets, but be patient and keep pouring on the plasma until you've taken out at least a few of them. You can even ram them for instant kills but be careful not to take too much fire. Then you can drop down lower and look for survivors. But be careful. On the Heroic and Legendary difficulties, their beams can tear up your Banshee in seconds, so don't try ramming them. Once you've turned them all to scrap, land on the platform. You'll find a health pack up here along with just about every kind of ammo under the sun. This is the end of the level, so grab the health pack. And for your weapons, let's choose a plasma rifle and a rocket launcher. Head on down the tunnel and peek into the next room. There are several Sentinels in here. Fire off a bit of plasma to get their attention. Stay in the doorway and they should come out into the exterior of the room to fight. These guys are tougher than the other Sentinels you've faced. They have shields. They're still pretty easy to take out however. Use your rockets on them when you feel like making explosions and gun them down with the plasma rifle to finish them off. Duck back to recharge as necessary. Once the coast is clear, head into the center of the room and walk into the pulse generator. Now just sit back and enjoy the cut scene. After that level, you have definitely earned it.

Oh yeah, and if you're confident, just go trigger happy and pistol anything in your way. Shotgun for the tough ones.

Weapons Cache
When you get the first Banshee, fly over to where the Control Room door is and fly behind the structure and on a ledge. There is a Sniper Rifle, Shotgun and Pistol and the ammo too as well as a lot of fragmentation grenades and a health pack. This can also be accessed by simply walking up the ramp that twists around the structure until you reach it.

Vacation
There is a vacation on this level, but it is not big. When you destroyed the four Sentinels in the beginning, head for the door but do not open it. Instead, jump on the edge on one of the sides of the bridge. Underneath, you'll have two sections of the plateau. You can easily see the difference because one is steeper than the other. Fall down of the edge of the bridge and try to land on the steeper plateau because when you land on the other section you'll fall in the "dead zone". When you land on the steeper plateau you, can have some damage at your health. This can be helped by first landing on a small edge on the higher plateau next to it. As said before, this is a small vacation. You can only walk on the steep plateau.

Different Way
There is a different way to get in the other sections of the control room itself. Destroy the four Sentinels that you encounter in the beginning. Head outside and kill all the enemies you encounter. Then, get into the Banshee and head back inside the control room. Now, you can fly all the way to the top and the bottom of the control room. You have also a closer look to the ring and the gas giant, Threshold and it's moon, Basis. When you fly to the top of the room, you can see that the darker structure of the room doesn't reach the top... so you can actually wedge yourself between (losing your Banshee; not much to do up there but it's kinda fun to fall off.) But there’s a strange thing if you fly under the bridge leading to the door. When you get near to the wall with the door on it, (but under the bridge) you'll die for no reason.

Trivia

 * About half way through the level, you will come across a room where when you first open the door and you will see a dead Stealth Elite and a dead Minor Grunt with Infection Forms on them. However, they will not attack you.
 * During the last part of the level when you come across a big Covenant emplacement with the two Wraiths, if you blow them up, a pair of Hunters, and other Covenant infantry, will spawn in the back of the two rocks behind the Banshees.
 * You can snipe the Wraith driver at the beginning of the level. When the music starts, aim at the Wraith and you will see an Elite. You still can't drive the Wraith, but this trick can help favourably in Legendary.
 * Just like in the level Assault on the Control Room, if you press start, you can still see the snow fall but nothing else moving.
 * When you emerge out of the tunnel in the chapter "Final Run", there is a tree with no bottom on the ledge on top of the tunnel. You can get in a Banshee and fly up there to see it.
 * Once you get the Banshee at the beginning of the level, you can fly up to one of the locked (red) doors and glitch yourself through the door by getting out of the Banshee while the back of the Banshee is hitting the door. The room is the same as a pulse generator room (w/o the generator) except once you fully enter the room, the detail on the graphics will be greatly reduced to anything in the room (including you and your weapons.)
 * During the "Final Run" chapter, if you get to some areas quick enough, no Flood will be there, then all of a sudden, a huge amount will spawn.
 * Master Chief has an Assault Rifle during the cinematic at the beginning, even though you start the level with a Shotgun and a Plasma Pistol. Although in the novel, Halo: The Flood, the Master Chief had an Assault Rifle with one and a half a clip of ammo and a Shotgun. Bungie probably did not want the player starting with a low amount of ammo in a weapon.
 * When playing co-op, even if one player isn't near the pulse generators, both players’ shields will drop.
 * In the circular rooms, you may hear a roaring sound. Deceptively similar sounds may be heard in Planar Sphere in Baldur's Gate II: The Shadows of Amn. It may be heard in the previous level, Assault on the Control Room, and the multiplayer level, Chiron TL-34, as well.
 * If you look at the Control Room while flying up, you can see the Marathon symbol.
 * This level is similar to the Halo 2 level, Quarantine Zone as they take place at night in a snowy place, has you fight to the Flood and Sentinels, involves the Index being stolen, and involves betrayals at the beginning or end of the level with someone who helps guide the player to the Index.
 * In the first cutscene, the flash that temporarily disables spark is probably a small EMP blast.

Glitch

 * Only works on co-op. There is a load point at the entrance to room of the second pulse generator which teleports either player to that location - depending on which player got there first. Have one player wait right where the load point would be, and have the other player burst into the room, making a B-line for the pulse generator, as the room is crawling with Flood. Once destroyed, have the player stationed at the load point walk back, triggering it, and teleporting the other player. Along with the player comes all of the Flood around the player. Virtually statues, they will stand there, having literally no AI. You can continue on, having completed the objective, or you can shoot them all, chuck grenades, and melee them, assuming you don't trigger the load point again. There will be no visual indication of any damage to the Flood. Once you feel enough grenades and rounds have been expended, re-trigger the load point. The Flood you shot will all drop dead.