The Truth and Reconciliation Walkthrough
From Halopedia, the Halo wiki
|Halo: Combat Evolved|
|The Truth and Reconciliation|
- Assault Rifle
- Sniper Rifle
- Plasma Pistol
- Okarda'phaa-pattern plasma rifle
- Plasma Grenade
- Fragmentation Grenade
- Ghost (non-drivable)
- Wraith (non-drivable)
- Pelican (non-drivable)
- Spirit (non-drivable)
- Ket-pattern battlecruiser Truth and Reconciliation(non-drivable)
Players start with a Sniper Rifle and an Assault Rifle. You only need the Sniper Rifle for the first half which is the key weapon in this level. Remember to spend only the necessary ammo of the weapon; there is almost no ammo for the sniper rifle. So watch out for extra ammo. Health packs will also be aside the ammo. The assault rifle is not so important and can be swapped for other weapons. Plasma pistols and plasma Rifles are good.
When you get off the Pelican, quickly find two paths. It is recommended to take the right. There is many areas where you can snipe from; it's very easy. The left side puts you in direct line of fire.
When you and the other marines reach the path, use your Sniper rifle to kill the enemies. If you can't see any, move to the right and enable your night vision scope. Your first priority is to take down the gunners on the shade turrets before they do any serious damage.
After killing the grunts on them, make you no one else will approach them. After clearing the turrets, concentrate on the Elites and Jackals. Two shots will drop the Elites. Use the plasmas to drain the Jackal's shields then melee them or use your sniper.
As soon as you see your yellow dots moving on your motion tracker, look for an Elite coming out of the path straight ahead. Kill him quickly with a headshot. Then move down where the Covenant set was and go where the Elite was, then kill the following Grunts. Follow the path where they came from. Here, there are four Grunts and two Jackals. Kill them, then move to the next sniping area.
My best sniping area is at the rock, quickly snipe behind that rock. Take out the gunners because they will be more of a threat if you are not careful, especially on Heroic and Legendary. Once you killed the Grunts and the Elites surrounding it, go forward to where their position was and turn right. There is an Needler Elite there. Snipe him, then turn around and go straight and follow the path.
Now at the end of the path, there will be an Elite. Take him out, then switch to your secondary weapon and kill the surrounding Grunts. Then after that, go find the path they came in and enter it. Now you have two choices.
1): Taking the middle: You will really need help on this. The best idea is to stick the Elite that has the Needler. Then pull out your Sniper Rifle and snipe the gunners ahead, then move on to the Left and take out the rest of the enemies.
2): Taking the left: Now take out the two jackals on your way to the left, look for a Shade near you. Then pull out your Sniper Rifle and kill the enemies across. This option might kill your marines, as they will be taking most of the firepower.
Either way works fine.
Now a Covenant Dropship will drop off reinforcements once all the infantry are down. Kill off the reinforcements with some cover. Take out the two Elites that show up and the grunts and the jackals. Now when secure, search for the two Shades turrets. Under them is a path to the Truth and Reconciliation's Gravity Lift. If you have no more marines, Cortana will call for reinforcements.
At the end of this path, several Grunts and two or three elites will jump at you. This is a relatively closed area, so throw a Anskum-pattern plasma grenade in the middle of the pack, then back away. Use your secondary gun to kill the survivors.
Once the place is clear, begin sniping. There is a rock near the end of the path that you can use to snipe from. Take out the shade turret to the right of you, then snipe the remaining enemies. Once you cannot see any more enemies, come from your cover and go up the path where the first shade turret you sniped from this rock was. Snipe the rest of then turrets and infantry.
Immediately after this, a Covenant Dropship will come with reinforcements. This dropship has only Jackals and Grunts. Kill them all. Then look to the gravity lift. Several Grunts, Elites, and Jackals will come to try and kill you. There will be three rounds. Using a shade turret can be useful, yet beware of the Grunts who will try and stick you with a grenade. You could also snipe here. The best way to deal with these forces is to use your Marines as a distraction while you kill the forces.
After dealing with the three or so groups, new music will play and Hunters will come out. Dodge their attacks and use your sniper rifle to hit them in the orange spot on the back or front. Some of your marines may die. Once the Hunters are dead, move up to the gravity lift. If you lost some marines, Echo 419 will come for reinforcements.
Once you're in, you're ready to begin the second half of the area. So be prepared. Now you want to be on a lookout on one of the four doors that will open for a Stealth Elite with a sword, use your Plasma rifle, save your Sniper Rifle for later.
Now, enemies will come out the other four doors. Most of the Elites are going to be cloaked with swords, so try to take them out before they kill your Marines. If you need to find cover, go inside the doors when they are open. Try to keep your allies alive, because if you are surrounded, you're dead. Also, if you are in need of a Plasma weapon, take one of the Plasma pistol, nothing wrong is going to happen.
Once you're 10 groups or dead, a bigger door will open for the Hunters. Dodge their attacks and use your sniper rifle on their orange back, then find an open door on one of the smaller doors.
When you find the small door, go up and turn right. Follow the path until you reach an Elite. Use your plasma pistol to take out his shields and grab his plasma rifle. Now when dead, go to where he came in, and enter the door. NOTE: There is Elites, Jackals and grunts here so I will follow these instructions carefully.
Stick one of them, and use your Plasma weapon the other, then take out the jackals. Now, you can stay on that level and take out the enemies on the higher pit with your Sniper rifle, It will be easier to hold them off. There is a Health Pack in the room if needed and some ammo for your Sniper Rifle.
When the pit is clear, clear your marines and get ready for some enemies. Use your plasma rifle on most of the enemies until you get the nav point, go into the nav point door when you get it, and go to the right and go to the end of the hall and turn right and kill the jackals and turn right again. There is Elites and grunts so I recommend your Sniper Rifle to take them out. Now go to the end to where they were and turn left and go down and right again and pull out your Sniper Rifle if has not already.
Use it on the ELITES ONLY, the one from the top and the one from your current level. Then use your Plasma weapon on the grunts and jackals. Cortana will call in reinforcements if have not already. Now grunts and jackals will drop in from where you came in so I suggest using your plasma weapon to take them out then move on to the next area.
Also, an overshield is available on the crates and ammo if needed. So refresh yourself. Also more enemies will come out from behind and on higher ledges so be aware of your surroundings. Also when the area is clear, two hunters will pop out to your current room, I recommend dodging their attacks and getting their orange spots with your sniper rifle. Then wait for the nav point (swap for your Plasma weapon also) Then enter the open door.
Once you enter, follow the path until you reach through a grunt pack and a pair of Elites Stick them if needed then continue following the hallway killing the grunts and eventually a pair of Stealth Elites. They don't have shielding so take them down on one or two hits from your Plasma Rifle and head up to the second level.
Now once you head to the second level, Cortana will call in reinforcements if you don't have any allies with you. You will face tons of Jackals and Elites and even grunts, so it advised to find some immediate cover. Once you cleared the area, turn right. Find the nav point and open the door for reinforcements, Grunts and jackals will also come through the doors from the right and left doors. Kill them quickly. Also, head toward the other side of the current level. (NOT THE DOOR YOU CAME IN, THE OTHER DOOR)
Now you got your reinforcements now time to move on. Enter the door and follow the path killing the Elite and the few grunts and jackals. Now follow the remaining paths killing enemies until you reach the third floor.
Turn right and pull out your Sniper Rifle, snipe the Elite with a headshot and kill the two grunts. Go straight to the end and turn left. Now if you turn around, Grunts and jackals will come out to where you came in. Snipe them then continue on.
At the end, a few jackals and grunts will come out from the door, your plasma rifle should work. And enter the door and an Elite will be there. Snipe him when he get to close. Then follow the path when you reach the checkpoint.
HEALTHPACK: Before you go into the door, turn right and there will be a Health Pack and ammo rounds for your Sniper Rifle. Then go back and turn left.
You are in the control center. Now pull out your Sniper and snipe the Zealot on the high edge. Then kill the 2 grunts and the Elites with your plasma weapon. Now hopefully, a jackal will come out from one of the doors. Kill him with your Plasma weapon. Then a Nav point will trigger through a door. Enter the door and grenade the 3 grunts. Then follow the path and you will encounter more grunts. Kill them and sometimes there will two jackals. Kill them also and continue to follow the paths. Now, when you reach the two jackals. Grenade them then go straight turn left and find an opening and turn right and turn left to the opening straight and you will be in a brig.
Open the jail cells and search that room for an Active Camouflage and ammo and a health pack. Once you find it, leave the brig and go straight and then left. two jackals will appear. Kill them quick.
Now you should have your Activate Camouflage on. See that Zealot at the end? Kill him in the back quick and then take out the two Stealth Elites and the three grunts that follow.
Now go to where the Zealot was, and there will be a switch, kill it and a Cutscene will activate.
Now after the cutscene, your main goal is to protect the captain. If he dies, you have to restart. So here is what you should do. When the cutscene is over, the door you left in will open for 2 Stealth Elites. Kill them quick with your plasma weapon then the jackals that follow.
Then go straight and make a left and you should see an Elite and 2-3 grunts. Snipe them quick. Then go to where they were and turn right and then turn left again.
There will be an Elite on the corner. Stick him while he's not looking. Then turn left and kill the 3 grunts and then turn right and kill the jackals ahead. Go to where they were and follow to the path back to the shuttle bay.
Now pull out your Sniper, because there are two Stealth Elites here. Snipe them quick, before they kill the captain.
Now, Cortana will call in Echo 419 to pick them up. However, Foehammer is unavailable as she is pinned down by Covenant air patrols. Now we must head back to the shuttle bay and commandeer the Covenant dropship.
Now when you hear the music starts, it's time to do some real protecting. Grunts will come out from the right door and the left. Take them out quick, because they will be focusing on the Captain. Now head into the doors they came in. And follow the path to the shuttle bay to where Spirit is. In there there is an Elite. Stick while hes not looking then kill the grunts. See the nav point activate the panel and you have completed the level on Heroic.
This level can be one of the most frustrating levels, let me give you an overview. You start off with a Sniper Rifle, one of the weapons a Halo Player would love and loathe in equal measures. Foehammer will drop you down somewhere near the Truth and Reconciliation, and you must venture into the ship to retrieve Captain Keyes.
Walk on until you get onto the high grounds behind a rock. Aim the Sniper Rifle in search for walking Grunts and Elites. You can fire as much Sniper rounds as you want as long as they hit their target. Take out the Shades first, they can get really nasty, then the Elites, two headshots can finish them off. Aim for the centre mass if they are runing though.
When you're sure there's no Covenant left in the vicinity, whip out your Assault Rifle and get in a shade, then start shooting the reinforcements. They won't all come within the range of your shade after losing the first squad so you'll have to go occupy the shade at the far end of the area.
The squad led by an Elite are tough, and they'll always aim at you instead of the Marines. Perform a no-scope kill by the Sniper Rifle so as to bring down the Elite's shield and let the Marines finish it off, while you hammer the Grunts.
You'll get a checkpoint as you move up the hill. Take note of this: This will be the only checkpoint you get in the whole area, so try not to screw up along the line.
Continuing, snipe the Grunt in the Shade, and then go for the Jackal next to him. Move your sights down, and blow away these few Grunts that stick their behinds around the sheltering rocks. Eventually, an Elite will show up. Proceed to dispose him off the cliff, then when things stop popping up like gophers move in a little.
There are two Grunts on the far right side of the upper ledge. Aim for one of them, then quickly move your sight down. A Major Elite will be hiding in a little corner there. Time to practice No-Scoping, right through the heart to take care of the shields, a quick melee to finish him.
Switch to your Assault Rifle, and move to the other side of the upper ledge and wipe out the two Grunts there. One of them should have dropped a Needler; quickly ditch your AR for it. There are two more Grunts and an Elite in this area, so concentrate your Needles on the Elite first, then mop up the Grunts if your Marines haven't yet. Two or three more Grunts will come down the path, use the rest of your Needler ammo to take them out. Now go back for your Assault Rifle, and fill up on ammo.
You will finally get another checkpoint at the beginning of the next area. Once again, this will be your only checkpoint for the area, so stay frosty.
There may be a Shade with a Grunt Gunning it on the upper ledge. Take him out before your Marines wake the rest up. Once he's down move your zoom to the other ledge, where there is always an Elite keeping guard. Sometimes he's walking; most of the time he's running, so this is a slightly tricky shot, but you can do it.
Now, move back to the starting point and look along the edge of the rock formation. You should see a rock just below a few feet to the right of the first shade you took out. Jump on that rock, and prepare to have some fun.
You will have to jump to look over the edge and fire at the Covenant, but that's the fun part. So, down to business. Aim for the first Shade you see, then aim for the Jackal that's coming across the natural bridge. A pair of Grunts might come up right in front of you; if so, let them meet the business end of your Assault Rifle.
Move your scope down and scrub those two Jackals on the natural bridge, and any Shade Gunners you can see. After they've bit the dust, jump down from the perch and move forward a little. You should see another large rock at the edge where the ground elevates into the natural bridge. Jump on the rock, then on the ground above, and crouch close to the first shade you decommissioned. Once again, plug any Gunners, Jackals, and other enemies that are visible.
Right about now, a dropship should be coming in to drop off a fresh contingent of enemy Covenant to attack you. The only one you can see on your side of the gulch is a Jackal. Shoot him, then revert to the 2× zoom and get ready for the other ones. Use your Sniper Rifle to blast the Elite, then switch to your Assault Rifle to mop up the Grunts. Once they're crisp, get off your perch, go down the left side, and finish off the two Jackals that were on patrol.
Once you’re back at Sniping spot #2, take a moment to access the situation. You have just sniped a whole Gulch-load of Covenant. Think you're done? WRONG! Move across the natural bridge, and keep you zoom on the patch of rocks and trees where your very first Active Camouflage power-up is. As the music starts, an Elite will step out of his hiding spot; Take him down. Then, turn around, switch to your Assault Rifle, and shoot the Grunts that are down there. After they're gone, keep moving across the bridge to find a hidden squad of Grunts engage your Marines. Flank them, and the Gulch is yours.
Reload both your guns, switch to your Plasma Grenades and your Assault Rifle, then move across the Active Camo.
All right, you have forty-five seconds to quietly kill as many Covenant as you can. Creep to the ledge across from the Active Camo, and drop down. A Minor Elite and a Major, followed by a group of grunts will rush out. Drop a grenade on the Major's helmet and assassinate the Minor. Hey look, the grunts are running. Stick one's face, and watch them get blown sky-high. Pull out your sniper and pop a bullet through the gunner above you and creep forward. There's a Minor patrolling the area in front of you. You don't need to scope for this-just pop his face open. Now a dropship and an onslaught of Covenant are coming in. Shoot the dropship's load (the covenant reinforcements from the gravity lift won't come through until you've killed the jackals from the dropship, so aim for them AFTER the grunts), and grab the Shade near where you came through to the gravity lift area (since the Covenant troops will have to go up the hill to where you are to attack you, thus bottle-necking their attack.) Open fire on the Gravity Lift and kill the Covenant as they come up the hill to attack. Your Marines will take care of the stragglers.
When you hear music start, the Hunters are coming. Jump out of the Shade and charge them. When one uses its shield to melee you, dodge, turn, and No-scope its back. You'll see a satisfying spurt of orange blood and the Hunter will go down. Rinse and repeat for the other Hunter. By now, your marines are probably dead, so Cortana will order reinforcements from Foehammer (the reinforcements will come even if not all your Marines are dead).
Alternate strategy: If you are playing the PC version (1.07), staying in the shade NEAR THE ENTRANCE TO THE GRAVITY LIFT AREA (not some other shade) and gunning the hunters is a very good way, to kill them as they will continuously miss you with their fuel rods.
As soon as they are dead, scour the place for ammo and grenades. Remember to take the frags from the dead marines because you'll need them. You may notice that the graphics in this game aren't exactly top notch (though they are pretty good for a 2001 game), but there are some scenes which just leave you staring at the breathtaking view, like the arc of the Halo extending over the sky, the ending cinematic, the silent cartographer level, the first level, the huge chasms and gorges, large indoor outdoor scenes, ice bridges, flood-covenant battles, Halo's Control Room, the light bridges, Proto-gravemind, the crashed Pillar of Autumn at "The Maw", etc, etc.
Well, here's another... look up... at the Ket-Truth and Reconciliation Battle cruiser. It's a real sight to behold.
Now jump into the Gravity Lift and watch the pretty cut scene as you're lifted into the belly of the beast.
Now you're in the loading bay, jump on the middle of the room, and check your motion sensor. A Covenant Stealth Elite (sometimes 2 on Legendary) with an Energy Sword will open a door and charge. Quickly put a few sniper slugs in him while he's getting angry (headshot works best), and he'll collapse and die. Now more Covenant reinforcements will slam into the room and attack.
There are two ways you can go about doing this, (do note that this walk through is for the Legendary difficulty) the easy yet long way and the obscenely (on Legendary) hard yet quick way.
First the balls-out strategy way: Try to keep as many Marines alive as you can. Thankfully there isn't a lot of Elites in this part, just 4 to 8 Zealots (all wielding energy swords). Your sniper rifle is key versus the Elites and your frags are very effective at killing the hordes of Grunts and Jackals that come through the doors. Use the med kit at the far corner of the room if you need it.
Second is the longer yet easier method, but it involves betraying fictional video game characters and leaving them for dead:
As soon as you've killed the first invisible Energy sword elite (and possibly another major elite if you were lucky), ready your grenades and throw them at the raiding parties that the Covenant send for you through the doors on the Right, on the same side as the med kit (the doors on the left lead to a dead end, that should also separate them). Once they are dead go through (only Covenant can open the door from the outside so try not to lock yourself out) take cover and wait for your shields to recharge while you reload your weapons and collect plasmas grenades from dead Grunts. (You can probably hear your Marines (which you abandoned fighting while you sit here) then jump out and shoot the Covenant one by one by opening and closing the door at your discretion, you may do this while your marines are still alive and get extra support, but without you to stop the energy sword elites, they're helpless. There's a squad of grunts and jackals that will pass through these hallways to get to the Gravity Lift loading bay.
Sometimes, energy sword elites will come inside after you, pull out your sniper rifle and put a few rounds in him. Try not to go for plasma grenades, as they'll run up to you thus killing you both, though it does occasionally work without substantial harm to you.
Notes for both strategies: If the energy sword elites get too close, immediately jump, as one swipe of the energy sword will kill you. Also, either strategy you use, your marines will probably die, if they don't, you're a better player than me. But it's not overly critical to your success if they die or not.
You might want to hide inside one of the rooms where the Covenant just pour out and snipe down the Grunts and Zealots. However, if TWO Zealots corner you in the room... you had better have extraordinary skills or luck. Otherwise you're as good as dead.
Once the fight is over a big door will open and a Hunter pair will jump out. Go and get the Active Camo from behind the crates, go around the hunters and put one sniper bullet each through the orange area on their backs (you're invisible, this will be easy). The area where they came from is sealed off; you'll have to use the other gate.
Go through and you'll come across two Grunts, kill them without making a noise (melee because you're probably still invisible). Go through and on the passage to the left, there should be a Major Elite. Stick him with a plasma grenade and shoot the grunts. The rest of the area is just navigating hallways and killing covenant patrols, not much advice to give you...
You'll come into a storage dump now. Clear out the few enemies standing guard there, more will come after you take these out. There's dead Marines with Grenades, Sniper ammo, Medkits, etc in the corner. Take some supplies and the Assault Rifle, if you don't already have one. Now lots of Grunts and Jackals led by Elites will come in. Grenade the first and second groups and then find cover. Unlike the Flood(explained in later levels), the covenant AI is more defensive then offensive, they won't come after you (except maybe the more aggressive Elites). Focus on the Elites and Jackals first and take them out with your Sniper Rifle (don't worry about using up ammo, there's lots more). Then mop up the Grunts. There will be multiple groups, possibly 4 or 5, though number of covenant per group will be small.
Now there are a few more hallways and then you'll come across a dropship bay with one Spirit dropship docked and one casting off anchor.
Now this may take a few tries, but you have a checkpoint right behind you so don't worry. As soon as you get the checkpoint, go forward, open the door and pull out your Sniper Rifle (you will have to be quick about this because the next patrol that will come through will be a real pain in the a$$ if you don't engage them first) and quickly shoot the MOUTH of the Elite standing next to the hanger doors, it'll take two shots, at least, on Legendary.
As soon as he's dead, ignore the two grunts and run towards the door on the corner of the room to the right of you, an Elite and two jackals will come out (sometimes three Grunts with Needlers). Stick an Elite or Grunt and watch the others blow sky high. Go inside and recharge your shields as you'll be under a barrage of fire from an Elite and 6 or 7 Grunts while you do this. If you succeeded, you've just killed 2 Elites, 2 Jackals and a Grunt or two (best case scenario) without them being able to get a single shot out, good job.
Now, peep out and you'll see several Grunts, kill them with your Assault Rifle (or whatever weapon you have, I recommend the AR though). As soon as they're dead look up at the top of the platform, there will be an Elite, when he shows himself, shoot his mouth with the Sniper Rifle. He'll retreat to a hiding place to recharge his shields. His head will be visible to you if you're still in the doorway, shoot it with your Sniper Rifle and he'll collapse and die. DO NOT USE THE SUPPLIES FROM THE DEAD MARINES YET (unless you REALLY need them), you'll want them later.
On Heroic and below, you'll get two fire teams (Two 5 man teams) as reinforcements (one after another if the first dies). On Legendary, you're all alone over here and since this walkthrough is for Legendary... I'll guide you as if you're alone.
Go into the middle of the room and use your Sniper Rifle to take out any Jackals on the second floor if there are any. Go to the other side of the bay (near the other dropship), and you'll find crates next to the platform. You can crouch and take cover under them (Covenant aim for your torso, not your head). Now more Elites, Jackals, and Grunts will come through. Use your sniper rifle for the Elites and Jackals and your Assault Rifle for the Grunts. Around two-three minutes after this latest group of enemies come, you'll get a checkpoint, so try getting them all as quickly as you can.
You might have noticed a few dead marines with ammo and Grenades by the other side of the room. Don't go near them yet. Come out and kill the remaining Grunts and Jackals on the second floor (if there are any there) with your Sniper Rifle. As soon as they're dead, you probably have very little health and ammo left. Walk over the dead Marine with the Medkit and you'll be replenished in all your needs. Now go back to the other side and pick up the Overshield.
Cortana will now try to hack into the Covenant ship systems and open a door, as soon as you hear her start saying this, make sure you have the Over-shield and run as quickly as you can back to where you started this room. There is a hunter pair that just joined the party. If they didn't see you then that gives you a good chance to take one of them down peacefully.
If they didn't see you, then they won't charge in swinging. Giving you the chance to compose yourself and sneak around the opposite end of the platform, take a good sniper shot and hit one of their necks(if you didn't, don't worry, but be careful because your last checkpoint was a long time ago). The other (or both if you missed) will come after you. Do not expose yourself to their fuel rod cannons, instead let them chase you.
Worst-case scenario: They split up and one comes through around each side of the middle platform, in which case it's going to be tough because they've surrounded you from both sides and there's very little cover that will protect you now. So, try to lure them through ONE SIDE on first contact. As soon as they're just around the curve, run as fast as you can to the other side (a whole lap around the platform), sniper rifle in hand, and you'll be looking at their backs, hit the orange part of their backs from behind with the rifle. He'll drop dead in one shot if you hit the orange spot. Now the other will realize he lost his bond brother and come after you, repeat the same trick and go around the platform and shoot him from behind. In the best-case scenario, it should be a 1-shot 1-kill deal in a row.
If you're still alive, the door will open and you'll go through and get a checkpoint. You're safe. Feel free to take a deep breath and then proceed and kill the grunts in your way. You've just killed 6 or so Elites, 7-9 Jackals, 15+ grunts and 2 Hunters without the help of any marines and on Legendary. Kudos to you.
Go up to the next floor and you'll see two jackals coming out of a door, throw a frag between them and run up behind the crate beside the wall near where the jackals died. Jump up and throw a PLASMA grenade over the crate at the elite in the doorway or near him. Unless he sees you before the plasma grenade explodes, he won't dodge it, he'll just stare at it until it blows.
Now finish off the 2 Grunts and 2 Jackals on the other ledge. Whatever you do, do not walk up to the middle platform yet because that will trigger more covenant reinforcements and you'll be caught between the jackals and grunts that you were engaging before and the Elite and Jackals that just came through now. If that happens, you will probably die unless you jump back to the first floor, enemies are very accurate on Legendary. They hardly ever miss.
Instead, whip out your sniper rifle and shoot them from where you are. When they're dead collect plasma grenades and walk to the middle platform. As soon as you hear the sound of the door opening, throw your entire load of plasma grenades at the enemy and back off to a good distance behind the middle platform (not near the door though on the other side though). Use your sniper rifle to finish off the survivors of the plasma barrage (if there were any). Now more covenant (an Elite and a squad of grunts) will come out and trap you in the middle.
If there are any survivors on the other side (where you threw the plasma grenades), then you have been surrounded and as I said before, Enemies on Legendary rarely miss. In this case, jump down onto one of the crates below (to prevent fall damage) and restock your dwindling ammo (there are two dead marines near the door Cortana opened) and go back all the way up, sniper rifle in hand. You will catch them off-guard, it should be very easy so go trigger happy with your sniper rifle, there's lots of ammo downstairs.
If there weren't any survivors to your original plasma grenade barrage then go back to the other side and use your sniper rifle to kill them from afar.
Now here comes a tricky part, the ship's command center, otherwise known as the Bridge. There's some health and ammo to the hallway on your left, take it if you need it.
Now for the tough part, there are 2 major elites, a zealot and 6 grunts over here. So run and gun isn't an option. Pull out your AR and run into the room and melee the nearest sleeping grunt. Then run like hell. Go back to the previous area, the game should give you a "loading... done" message. It'll unload the previous area from it's memory and load the new one. Now go back, the covenant won't remember you because their AI was unloaded from the memory, so you can do multiple surprise attacks this way by going back and forth between loading areas. It gives a considerable advantage.
You can use this trick with all enemies near load points. Use the sniper rifle on the Elites and the AR with the grunts. Remember to avoid the Energy Sword Zealot.
Now move into the next area to the brig, there should be two brig areas. One has no guards and no live marines either, but lots of much needed supplies.
The other one holds Keyes and 3 other marines. There are multiple Zealots and Jackals guarding them. Mostly invisible. Though they shouldn't be a problem.
Free them and watch the cut scene. As soon as the cut scene ends, two more invisible elites with plasma rifles will come through. They are quite capable of killing Keyes and most of your marines if left to run their course so shoot them with your sniper rifle the moment they open the door.
Open the door and kill the two Jackals. Now fill up on your sniper ammo. You're leaving this area so fill up on everything you can. Now there's a fairly formidable group of Covenant that have an advantage in their position and availability of cover. There is an empty hallway between you and them, with absolutely no cover. Use all your frag grenades on them to scatter and disorganize them and charge in. Remember to take the lead so your marines and Keyes will have less chance of dying. Once you've broken this group's lines, the rest is fairly easy all the way back to the Bridge.
Once you get to the door leading to the Bridge there will be two invisible elites with energy swords. Wait until the walk by each other to take them both out with a single sniper rifle shot.
Now after the dialogue between Keyes and Cortana is finished, there will be a whole posse of Grunts through those doors.
Run to the back of the room (there are no doors on that side) and wait for them to finish talking. When the music starts, the Grunts are coming. They'll focus on throwing grenades and will take all your fire without answer. Remember, losing Keyes is mission failed. These Grunts are the Covenants best bet at taking him down, so stay away from the grunts.
Use all your plasma grenades on them. They must not get the chance to throw anything on Keyes. He's very fragile. On Legendary, 1 or 2 plasma pistol hits will take him down so stay vigilant.
Now the Level will end soon, you'll arrive back at the hanger bay. There's one last covenant group here, an Elite, a few Grunts and Jackals. Stick the Elite and use your AR on the grunts and Jackals. Your marines will be useful. Remember to always stay in front of Keyes. Block their fire with your body.
After you're done with them, it's simple, just activate the Hollow-panel and Mission Accomplished.
You've killed 3 Hunter pairs (4 counting end cut scene), 18-20 Zealots, 30+ Elites(Majors and Minors), at least 4-5 dozen Jackals and 70+ Grunt(including the enemies on the ground as well as in the ship) at a loss of around 15 marines(on Heroic and below, you get more reinforcements then Legendary, so that should be around 25). According to the story, Master Chief just killed half the ship's active fighting force and 1/3 of the crew.
Truth and Reconciliation
The Silent Cartographer