Crow's Nest

Crow's Nest is the second campaign mission of Halo 3.

Plot
The level begins with the Chief, the Arbiter, and Johnson landing in an underground UNSC base. As they disembark, several marines are amazed to see a Spartan. Commander Keyes then informs the Chief and Johnson of the current situation (that Truth has almost destroyed the UNSC Home Fleet, and only a few ships are left), all the while walking through hallways littered with wounded UNSC soldiers. They soon reach the command center and speak with Lord Hood, discussing a plan for an all out attack on Truth's army. However, the Covenant then jam the humans communications network along with the rest of the base, shutting off the power. Truth then appears on the main view screen, threatening the humans and telling them their world will burn. The Covenant then attack and the base comes under heavy fire from the Covenant Loyalists. Unable to sufficiently fight off the invaders, Miranda Keyes orders a bomb placed in the operations center. Despite an attempt by the Covenant to disable the bomb, it goes off successfully, and all remaining troops, including the Master Chief, escape into the base's underground garage where they survive the explosion.

Transcript
{Cutscene}


 * Crow's Nest Flight Controller: "Sorry for the tight squeeze. (To the other Flight Controller) Tell the Commander her ace is in the hole."

''Kilo 23 touches down. Medics load an injured marine on a stretcher and move. The Master Chief, the Arbiter and Johnson get off. Marines sitting by the landing pad see the Chief get out of the Pelican.''


 * Landing Pad Marine: "Hey, check it out.


 * Landing Pad Marine: "No way! A Spartan!"


 * Blind-by-injury Landing Pad Marine: "For real? You better not be....


 * Landing Pad Marine: "No man. He's here! We're gonna be alright!"

Commander Miranda Keyes comes out onto the Landing Pad to meet Johnson, the Arbiter and the Master Chief.


 * Commander Keyes: "Where'd you find him?"


 * Johnson: "Napping. Out back."


 * Commander Keyes: "Hmm. I'll bet. It's good to see you Chief."

Keyes shakes the Chief's hand.


 * Master Chief: "Likewise, ma'am."


 * Commander Keyes: "Let's get you up to speed."

''Down the hallways of the base, wounded Marines lay against the walls. Two Marines chatting to each other notice Commander Keyes and the Master Chief. They make way and salute.'''


 * Commander Keyes: "The Prophet of Truth's ships breached the Lunar Perimeter. Smashed what was left of the Home Fleet."

As the Arbiter walks by, the Marines lower their hands and stare in astonishment.


 * Commander Keyes: "Terrestrial casualties from the subsequent bombardment were..."

Medics race pass by with an injured Marine on a stretcher.


 * Commander Keyes: "...extreme. Truth could've landed anywhere, but he committed all his forces here. East Africa, The ruins of New Mombasa. Then, they started digging."


 * Master Chief: "What about Halo?"


 * Commander Keyes: "We stopped it, but only temporarily. Now, the Prophet of Truth is looking for something called 'The Ark', where he'll be able to fire all the Halo Rings. If he succeeds, Humanity, The Covenant, every sentient being in the Galaxy..."


 * Master Chief: "The Rings will kill us all."


 * Technician: "Ma'am, I have Lord Hood."


 * Commander Keyes: "Patch him through."


 * Lord Hood (Main View Screen): "Good news, Commander Keyes?"


 * Commander Keyes: "As good as it gets, sir."


 * Lord Hood (Main View Screen): "So I see. What's your status, son?"


 * Master Chief: "Green. Sir."


 * Lord Hood (Main View Screen): "Glad to hear it. The Commander's come up with a good plan. But without you, I wasn't sure we could pull it off."


 * Commander Keyes: "Truth's ships are clustered above the excavation site. And his infantry has deployed Anti-Aircraft Batteries around the perimeter. But, if we neutralize one of the batteries, punch a hole in Truth's defenses..."


 * Lord Hood (Main View Screen): "I'll initiate a low-level strike. Hit 'em right where it hurts. I only have a handful of ships, Master Chief. It's a big risk. But I'm confident-"

The power cuts completely.


 * Technician: "Ah Hell! Not again!"


 * Commander Keyes: "Emergency generators! Now!"


 * Marine Technician: "Shielding failed. They're down and charging."


 * Commander Keyes: "As soon as they're up, reestablish contact with Lord Hood. Let him know that-"


 * Truth (All screens): "You are, all of you, vermin. Cowering in the dirt, thinking...what, I wonder? That you might escape the coming fire? No! Your world will burn until its surface is but glass! And not even your Demon will live to creep, blackened, from its hole to mar the reflection of our passage; the culmination of our Journey. For your destruction is the will of the gods! And I? I AM their instrument!"

The power returns.


 * Johnson: "Cocky bastard. Just loves to run his mouth."


 * Master Chief: "Does he usually mention me?"

Commander Keyes thinks, and realizes Truth's meaning.


 * Commander Keyes: "Give the order. We're closing shop."


 * Marine Technician: "Ma'am?"


 * Commander Keyes: "We're about to get hit."


 * Marine Technician: "All personnel. Defense code Alpha."


 * Commander Keyes: "The wounded. We're getting them all out."


 * Marine Technician: "Prepare for immediate evacuation."


 * Johnson: "If I have to carry 'em myself."


 * Marine Technician: "Ma'am, squad leaders are requesting a rally point. Where should they go?"

''Miranda walks up the stairs and draws a Pistol. She pulls the slide back.''


 * Commander Keyes: "To war."

She lets go and moves on.

Know Your Role...
Perimeter breach.

{Gameplay}


 * Marine Technician: "We just lost the Perimeter Cameras."


 * Commander Keyes: "Motion Trackers?"


 * Marine Technician: "They're down or we're not receiving. Can't tell."


 * Commander Keyes: "Any of our birds squawking?"


 * Technician: "No ma'am. Wait, Overwatch has contacts. Phantoms! Closing in on our position."


 * Commander Keyes: "Any birds less than 5 minutes out, bring them in. Tell everything else to scatter."


 * Technician: "Aye Aye."


 * Technician : "Who would've thought we'd have this many wounded?"


 * Technician: "Pelicans are gonna take extra time to load."


 * Commander Keyes: "We knew they'd find us eventually. But we have a plan, let's make it happen."


 * All personnel: "Yes Ma'am!"


 * Johnson: "Arbiter and I will guard the Ops Center. Don't worry about the Commander, Chief. I got her. But the Marines downstairs could use your help."

- (Co-op variation) Johnson: "Chief, move out. You too, Arbiter. The Commander will brief you as you go."

The Master Chief meets with two Marines from downstairs.


 * Marine: "Follow me sir."


 * Marine: "Perimeter's this way."

The Chief follows the Marines downstairs.


 * Marine: "Come on sir. I'll show you the way."

The Chief finds many weapons to stock up on.


 * Marine: "This base was built for some 20th Century war. It's full of old tech, like these door controls."

''The Marine opens the door. The Chief walks on through to find Marines in a large cave setting up defenses for the Ops Center.''

or
 * Marine Sergeant (Reynolds): "Get those turrets up. You watch your fields of fire."
 * Marine Sergeant (Stacker): "Get those turrets up! Watch your fields of fire!"


 * Marine: "How'd they find us?"


 * Marine: "Probably just smelled you, man."


 * Marine: "Hey, bite me. I'm sick of hiding anyways."


 * Marine Sergeant (Reynolds or Stacker): "Quiet. Cut the chatter."
 * Marine: "What is it, Sergeant?"


 * Marine Sergeant (Reynolds or Stacker): "Calm before the Storm, Marines. Enjoy it."

The cave shakes.


 * Marine Sergeant (Reynolds or Stacker): "Point of entry, best assessment?"


 * Marine: "The Hangar, Sergeant."


 * Marine Sergeant (Reynolds or Stacker): "Agreed. Master Chief, get there."

- (Co-op variation) Marine Sergeant (Reynolds or Stacker): "Agreed. Chief, Arbiter. Get there."

The Master Chief proceeds on, meeting up with two Marines.


 * Marine: "We're with you, Chief."


 * Marine: "Yeah. Get some."

The Chief grabs some Fragmentation Grenades from a weapons case near the door, then opens it, and lets the Marines lead the way.


 * Commander Keyes (COM): "Chief? Good, this channel is secure. My fire-teams are spread thin. We can't hold out forever. I need that hangar cleared for evac, ASAP."


 * Marine: "Those Brutes secure the hangar; we won't be able to get our birds out."

''The Marines find the vehicle access. A Warthog is in battle with many Covenant soldiers. Grunts lob Plasma Grenades and destroy it. The Chief and accompanying Marines engage and win, pushing onward. They reach an open door heavily guarded and defeat the resistance, continuing through into the narrows corridors.''

''If the Master Chief continues to the end of the vehicle access, there is a Marine knocking on the door asking for the doorman to let him in. This is a Red vs Blue easter egg, the voices and the lines depend on the difficulty level. (See the Password-Lacking Marine)''

Soon the Chief and Marines reach the hangar.


 * Marine: "Wipe those bastards off the deck!!"

''The Chief and Marines on the offense secure the deck. Multiple Phantoms drop troops into the hangar, attempting to defend it. From a distance, Hornets and Banshees are seen to be engaged in an aerial fight near a Cruiser who keeps supplying Covenant reinforcements to the base. The Chief and Marines take turrets and defend the hangar. The UNSC forces prevail. The Phantoms retreat and the troops fall.''

''The Pelican hanging on a crane in one of the docks slides out and is released. The Dropship lands to evac the Marines in the hangar, while the Master Chief restocks on weapons and ammo.''


 * Pelican pilot (If the Chief is in the way where it lands): "Need you to step aside sir; can't land till you do."


 * Johnson (COM): "Chief, Ops Center. Double time! The Brutes are pressing hard."

''The Chief heads back to the Ops Center. Marines pass by for Evac. Back in the vehicle access, two Marines staying behind until the next Evac hear sounds of Drone's wings beating and metal banging in the ventilation pipes.''


 * Marine: "Hey. You hear that?"


 * Marine: "Yeah. And I don't like it."


 * Commander Keyes (Speaker): "Attention! Hostiles reported outside the barracks."

The Chief heads back into the corridors, with the two Marines following.


 * Commander Keyes (Speaker): "Barracks are under attack! All available combat teams, respond!"

''The COM systems remain silent. The banging and fluttering noises continue on.''


 * Commander Keyes (Speaker): "Anyone in the barracks, I need a SitRep. Now!"

The Master Chief meets with the Marines in the cave, defending the Ops Center.


 * Marine: "Sir. This way."

''A Drone suddenly appears above him. {It can be killed before it picks up the Marine. If it does, he can still be saved if chosen too}.''


 * Female Marine #1: "Look! Coming outta the vents!"

A whole swarm of Drones starts pouring out the ventilation shafts, and engulfs the room.


 * Marine: "Line 'Em Up! Line 'Em Up!!"


 * Female Marine: "What the hell are these things, Sergeant?!"


 * Marine Sergeant (Reynolds or Stacker): "Drones! A whole swarm! Take 'em down!! Short, controlled bursts!!

''The Marines open fire on the swarm. The Chief finds a turret and unloads on them. The mighty swarm eventually falls. Marine in the Ops Center open the doors, letting the Chief in.''

Gift With Purchase
Butchers in the barracks.

''The Master Chief meets with Johnson smoking a cigar and other defending Marines setting up an explosive device, but the Arbiter isn't with them. (Single Player Only)''


 * Stacker or Reynolds: "If I try to hook up a timer, it might just go off by itself."


 * Commander Keyes (Main View Screen): "Johnson."


 * Johnson: "Mmm hmm?"


 * Commander Keyes (Main View Screen): "You might wanna put that out."

Johnson drops his cigar and stamps on it.


 * Commander Keyes (Main View Screen): "Chief, have a look. A little going away gift for the Covenant. We've linked it to smaller charges throughout the base. Johnson, soon as the evacuation is complete, start the timer."


 * Johnson: "Understood."


 * Commander Keyes (Main View Screen): "Good luck everyone. See you on the last Pelican out."

The Main View Screen switches off.


 * Johnson: "Follow me, Chief."

- (Co-op variation) Johnson: "Chief, Arbiter. Follow me."

Johnson leads the Chief to the back of the room, guarded by four Marines, and a Weapons Locker sits by it.


 * Johnson: "Brutes have taken the Barracks. Marines are trapped inside. Those apes ain't much for mercy, Chief. We both know what they do to prisoners."

The Master Chief takes weapons and ammo from the locker.


 * Johnson: "Get to the Barracks, save those men. Then escort them to the Landing Pad for evac."

If you stay near the bomb


 * Johnson: "I'll guard the bomb Chief, get yourself to the Barracks."

''The Chief heads through the corridor to the Motor Pool. While down there, he spots a Brute Pack, lead by a Brute Chieftain with a Gravity Hammer.''


 * Brute Chieftain: "A fresh scent. Must be close. Spread out! Track it down!"

The Brutes disperse; the Chief takes the pack and Chieftain head-on alone.

''After wiping the Brute Pack out, the Master Chief continues on through a corridor, but it's caved in. Finding a hole in the floor, he jumps down into a shaft, and at the bottom, are several pipe entrances, where Drones fly in and out of. ''
 * Cortana (Cortana Moment): "You have been called upon to serve."

Master Chief jumps down through the shafts into a canal, where he finds the Arbiter below, fighting off another swarm of Drones.


 * Arbiter: "Half-wit insects! The Prophets use you like they used me! Reject their lies! Rebel, or all your hives will perish!"

After the Arbiter takes care of the Drones, the Chief and the Arbiter regroup.


 * Arbiter: "Spartan, the Brutes have taken your soldiers, as prisoners or meat for their bellies, I do not know. If some yet live, let us be careful when we shoot."

''The Master Chief and Arbiter head through the door, seeing a Prisoner Marine thrown into a pillar, where multiple marine corpses lie. The Chief and Arbiter rush in. One Marine being held by a Brute begs for mercy as it decides to kill him too.''


 * Marine Prisoner: "No! Please!"


 * Brute: "Look, it has soiled itself! These are whelps, not warriors!"

''The Chief and Arbiter kill the Brutes and release the prisoner {optional}. While the Marine rushes for a weapon, the Chief and Arbiter save every prisoner they can. Taking out the Brutes, the surviving Marines grab weapons from more piles of corpses, taking a second to grieve for their comrades while the Chief and Arbiter too resupply and reload. They continue their rescue throughout the barracks, defeating the Brutes and rescuing (a maximum of) seven Marines, including a Sergeant.''


 * Arbiter: "We did all we could. Let us move the survivors to the landing pad. There is a lift outside."

- (Co-op change) Marine Sergeant (Reynolds or Stacker): "You did the best you could, Sir. Let's get the survivors up to the hangar. There's an elevator just outside the barracks."

''The Chief leads the survivors outside to the lift. He activates it and they wait for it to come down. While they wait, matters get worse.''


 * Johnson (COM): "Commander, we lost the Ops Center. Brutes attacked in force. Couldn't hold them off. We're falling back to the hangar. But don't wait for us."


 * Hocus (COM): "What should I do, ma'am?"


 * Commander Keyes (COM): "Hold position! I'm not leaving without him."


 * 'The Chief, Arbiter and the Marines board the elevator back up to the flight deck. While heading up, Kilo 23 gets into trouble.


 * Hocus: "Ma'am, I've got movement. Above and below. Brutes. They got jump-packs."


 * Commander Keyes (COM): "They're going after the thrusters. Shake them off, Lieutenant!"

''Kilo 23 takes off, getting out of the Brutes' reach. Noticing the Chief and Arbiter, they attack them. After successfully retaking the flight deck, a door at the road below opens. Seeing Johnson and his surviving squad at the doorway under attack from Drones, the Chief and Arbiter assist.''


 * Johnson: "Drones! Go! I'll cover you!"

''The few drones are quickly eliminated. Kilo 23 returns for final evac. The Barracks survivors and Johnson's squad board the Pelican Dropship.''


 * Johnson: "Brutes. In the Ops Center. They disarmed the bomb. Sorry Commander, there were too many. Even for me."


 * Commander Keyes (COM): "Chief, get back to the Ops Center. Kill those Brutes. Rearm the bomb. I've gotta get these men outta here. But I'll radio with another exit. Good luck."

''Johnson and the Arbiter board the Pelican. The Master Chief goes along the road Johnson previously came from, passing by destroyed Warthogs and dead Marines. (In Co-op, the Arbiter will accompany the Chief)''

Last One Out, Get the Lights
'Bomb armed. Time to go.'

The Chief reaches a door at the end of the road.


 * Cortana (Cortana Moment): "You will be the protectors of Earth and all her colonies."

''The Chief walks on through to another roadway, with Covenant Plasma Cannons set up. Using the Plasma Cannons and/or using all available cover, he gets back to the Motor Pool next door to the Ops Center.''

If the Chief is taking a while.

Johnson (COM): "Head through the Motor Pool to get to the Ops Center."

The Chief heads back up the corridor behind the Ops Center, and sneaks in and witnesses a Chieftain communicating with the Prophet of Truth using the Ops Center communications.


 * Brute Chieftain: "Success, Holy One. We have taken their Command Center!"


 * Truth (Main View Screen): "Have you discovered how they plan to stop me?"


 * Brute Chieftain: (Nervously) "Not just yet, Noble Prophet."


 * Truth (Main View Screen): "Find out what I need to know, or your place on the path is forfeit. Tell me you understand!"


 * Brute Chieftain: "Yes, Holy One. It shall be done."

Truth disconnects from the screen..


 * Brute Chieftain: "Have the Drones scour these machines!! Find out what these heathens know about the Ark!!"

As the two Grunts and Brute Captains get busy, the Chief takes them by surprise and takes them down, taking back the Ops Center and the bomb.

If the Chief waits around a bit.


 * Johnson (COM): "Hit the switch, Chief. Arm that bomb!"

The Master Chief reactivates the bomb and the alarm sounds.


 * Commander Keyes (COM): "That did it, Chief! Bomb's armed."


 * Johnson (COM): "We got your exit. A service elevator in the hangar. Head downstairs, cut through the caves!"

The Chief heads back into the cave, where grunts run wildly, then through the corridors.


 * Cortana (Cortana Moment): "There will be a great deal of hardship on the road ahead."

He continues back out to the vehicle access, where Drones, some Jackals and Grunts flee, and back down the corridors to the hangar.


 * Cortana (Cortana Moment): "You will become the best we can make you."

The Chief gets to the hangar, where Phantoms flee, and Grunts run around in panic and some trying to catch the fleing Phantom, holds up and looks miserable.


 * Johnson (COM): "There isn't much time, Chief. Find that elevator."

''The Master Chief makes it to the service elevator, and activates it. The door doesn't fully shut. Something explodes and flames flicker through the gap.''


 * Cortana (Cortana Moment): "This place will become your home."

''The elevator descends. The Master Chief hears a massive boom. He looks up and sees the flames roar through the open door. The violent shaking disconnects the elevator and sends it plummeting down. It crashes below and the Chief starts to black out.''


 * Cortana (Cortana Moment): "This place will become your tomb."

Everything goes black.

Walkthrough
As the level starts off, listen to the dialogue, and then move down to the weapon lockers for some ammo. Grab a Battle Rifle and two SMGs. After a marine opens the door, go all the way to the top, where you'll meet two marines telling you about a hangar. At this point it is a good idea to swap your 2 marines Assault Rifles with Battle Rifles to increase their effectiveness. Go to the panel and open this door. From here, find your way and be sure to open the doors you encounter (only those doors with a green light can be opened). Soon, you'll approach a big area with a warthog, if you want, you can move in as quickly as possible and throw a grenade at the grunts as they blow up the warthog. Draw out your BR and begin sniping out the grunts and jackals, hiding if necessary. When you come to the next door, a brute and several grunts will come out. Kill the brute first, then kill the remaining grunts. Now, do NOT eagerly go through the door yet! Several jackals are at the end of the hallway sniping with their carbines. Using your battle rifle, snipe each one out, then kill the grunts, or throw a Frag grenade down the hallway where they are. Once the area is clear, proceed. Swap your SMGs for a Carbine. You'll arrive at a hangar, where there are grunts and jackals on the deck. Kill every one of them. By this time, a phantom would have arrived. If you bump into the other Marines swap out your BR and Carbine with their weapons to increase their combat effectiveness. Pick up a deployable cover that can be found on the deck, then go to one of the Machine gun Turrets. Place the cover at the side of your turret, so that if any enemy gets on the deck, they can't shoot you. Okay, now use the turret to shoot everyone on the hangar bay. Destroy the drop ship plasma cannons when they fly into the hangar. DON'T detach the turret yet until the pelican comes out (Just come out of the turret and use your weapons to shoot those enemies that managed to get on the deck). That is, after you have cleared several troops deployed by the phantoms. Now, having cleared the hangar, detach the turret (preferably one on the left side as the elevator to exit is on the right) then pick up a new deployable cover and get back to the ops center exactly the same way you got to the hangar. Beware, on your way there, you'll encounter lots of drones in the cave. Remain in the bunker and use your turret to kill the drones, and hide whenever your shield is down, (preferably stay behind the wire mesh as there is a lot more cover and the drones can't swamp you), or you can find a battle rifle cache next to the left exit of the wire mesh part of the cave. If necessary use your deployable cover. After clearing the area, proceed on to the ops center. There is a Machine gun turret to the left of the room with the wire mesh. Grab it; it will come in handy when you have to kill the Chieftain.

From the ops center, go to the other door where you can find a green light and a marine standing next to the door. Pick up a shotgun. Open the door, and proceed to the barracks. Be sure to have a power drain. Here, use the shield as cover and shoot through the hole. Drop the Turret, it's more helpful against the chieftain. If you have a power drain, throw it strip the armor of the brutes to make things a bit easier. Kill the brutes one by one, in co-op, as long as it is not an iron game, one of the co-op players can arm them self with as many stick/plasma grenades as possible, then walk right up to brutes and melee one in the back, and then (if it is possible) stick them, being armed with plasma pistols will help your friend at the back sniping, because one fully charged shot will completely strip a brutes power armor. If you find yourself in a situation with a berserk brute (and even, possibly the chieftain, wait for them to try and melee you, dodge it, go round them to the back, and melee them. An easy way to do this in single player is to take one of the gravity lifts in the center of the walkway and use them to get on the catwalk on the right. There should be a room nearby with a ton of shotgun ammo. Use the room as cover and blow the Brutes away as they come at you, in the small room they will often try to melee you so make sure you don't accidentally back into a corner with no way out or around a meleeing/berserk brute. Soon, the chieftain will go in to kill you, you should get out in the open so he can not pin you against a wall. Dodge his attacks and don't shoot if he activates his Invincibility. Now use the Turret, or you can try to lure him to a corner, then throw a spike grenade, and that should finish him. If any brutes are still there kill them, but don't become complacent, one brute is more than enough to finish you. Take the chieftains hammer with you and proceed to the next area. In the tunnel, the drones won't usually harm you much, and you can either ignore them, or fight them.

Here, you'll encounter the Arbiter, and he will help you through the cave and the next area (the second barracks). You have the opportunity to save marines in the barracks, you can immediately walk up and melee the brute that is choking the marine, and if you are quick with grenades with just about manage to get about three brutes before being forced to retreat, but that works best in co-op. The marines tend to pick up weak weapons so swap out their weapons with Battle Rifles, Carbines, Shotguns and Assault Rifles. The Gravity Hammer works very well here. Just be careful, there are jackals on the walk-way, and they can deplete your shields at the most inopportune times. Snipe out some of the brutes first, then use your gravity hammer to kill the rest, remember that the bubble shields they throw up are excellent cover for staging one on one's with brutes, and that your gravity hammer will most likely destroy them when you attack with it, so regular melee will probably suffice (that is, if the bubble shield is the only thing stopping a small hoard of brutes coming down on you). Kill the others before facing the gold chieftain. Rush toward him, and blast him directly with your hammer. That should kill him, or, just before your confrontation with him there is a door with a green light, when you go into it after opening it leads you roughly to the back of the brutes, it is excellent for co-op, allowing the marines and other player to distract, while the player that went through the door can put in a handy power drain, or go invincible (if the equipment dropped from one of the previous chieftain's), or can skulk around until an opportune moment such as an excellent opportunity to melee the chieftain in the back, (bubble shields are excellent too), though for single player, it would probably be better if you left that door alone, as it provides an avenue for the brutes to come from behind you. After clearing this area, you will go to a cave with an elevator. Get into it and activate the controls. You'll soon come to a landing pad, with lots of Jump-pack Brutes, you should immediately move down the stairs while the brutes are focusing on the pelican, and melee one of them in the back, in order to kill him immediately, then immediately retreat.

After killing all of them, go up to control room over the landing pad to pick up an active-camouflage equipment. Then proceed down the stairs to an area where you will encounter drones. You can ignore them or fight them if you want.

At the next area, you will encounter lots of gunner grunts with their plasma cannons. Be sure to hide frequently here, as your shield will go down frequently too. Feel free to use your own tactic here, but I suggest detaching the turrets. If one turret runs out of ammo, you can always detach another. After you've cleared this area, you'll come to another area with loads of grunts and two jackal snipers up on the upper level, carrying beam rifles. Take them out first, as they are the most dangerous, in co-op, where two of you have an active camo, one of you can choose to maneuver behind all the grunts and take the jackals out, while the other player focuses on the Grunts, be careful when trying this tactic, because if you are hit or accidentally hit by a Plasma Grenade, it won't work. Behind a crate is a BR. Temporarily swap it with one of your weapons to take out the jackals if you don't already have one. It takes practice, but after you've killed them, kill the remaining grunts. From here, open the last door, and you're back again at the ops center. Use your active camouflage to clear out this room of Grunts and Brutes, in co-op, the one with the remaining active camouflage should (without the other player doing anything to attract there attention, though he/she might like to wait just behind the brutes so as to stick one as soon as you assassinate the Chieftain) maneuver around all the other brutes and melee the chieftain there, be careful when doing this, the every-one in the area will stumble after an explosion, and they can stumble into you, which can be fatal. Arm the bomb, and proceed to the hangar the same way as when you first went to the hangar. Most covenant are now disoriented, and you can feel free to ignore them; just watch out for the Jackals, and try to not attract there attention, they can be immediately stop be disorientated if you kill one of them, and it just makes it harder, though it doesn't matter much on the lower difficulties, it can make legendary/iron games much harder to do. After arriving to the hangar, you'll notice that on the right side of the hangar, a hangar door has opened. Get through it, dash to the elevator, and activate it. The bomb explodes. Congratulations you just beat The Crow's Nest.

Note: Just before the barracks, you can push the Marines to help you against the Brutes.

Achievements
Holdout - "Holdout" is an achievement earned by completing the level on the Normal, Heroic, or Legendary difficulty. It is worth 20 Gamerpoints.

Black Eye - "Black Eye" is an achievement earned for finding and claiming the Black Eye Skull. It is worth 10 Gamerpoints.

Demon - "Demon" is an achievement earned by accumulating 15,000 points in free-for-all meta-game scoring on this level. It is worth 10 Gamerpoints.

Trivia

 * In this level,there is a door that opens automaticlly.It is found in the hall where you first see Jackal Marksmen and where two Marines come out of the door.This is the door that opens automaticlly.
 * It is possible to flip a Phantom on this level.
 * In the beginning of this level on single player, a glitch occurs where you can see through the Arbiter's eyes.
 * Marines on this level have occasionally been observed to be aimlessly wander past Brutes, weaponless. The Brutes however, appear not to notice these Marines.
 * There is an argument between two marines voiced by various Red vs Blue voice actors, which changes depending on difficulty level. See Password-Lacking Marine. The third part of this level (Last One Out, Get The Lights) could be a reference to the Season Two finale of Red vs Blue (Last One Out, Hit The Lights).
 * Behind the arguing Marine there's a lone pistol on the floor, if you go there in the theater mode it's standing up but when you get there on foot it's lying down.
 * It is seen in the Halo 3 ViDoc Et Tu Brute around the 5 minute mark.
 * There is a way to get a weapon before your supposed to. To do this get the skull at the beginning of the level and then follow Miranda up the stairs. Then once up there kill the Marine and voila, you got a gun.
 * The words spoken by the Prophet of Truth in the E3 2007 trailer of Halo 3 are heard in the cut-scene when the Covenant hack into the Human communications network.
 * Also, when Truth says: "...your destruction is the will of the gods. And I? I AM their instrument!" is the same line a Major Elite says in The Fall of Reach and Halo E3 2000 Trailer.
 * On the boxes in the part of the room farthest from the monitors is the number 2401, the number of Installation 05's Monitor.
 * In the first hanger, there is a generator under the floor that has the number 2401, like Installation 05's Monitor.
 * The "Seventh Column" icon appears in the opening cinematic. Immediately after Commander Keyes says "Give the order, we're closing shop," the screen cuts to a bearded marine who says "Ma'am?" The screen behind him reveals a map of the base, with the Seven Pillars icon appearing in the middle of the lower-right quadrant. [[Image:Seven_Pillars.png|right|thumb|250px|The "Seventh Column" icons that appear on the computer readout.]]
 * The computers in the Operations Center occasionally beep the Halo theme.
 * The computers show the same information as the computers in The Pit's sword room.
 * Occasionally, you will see rats scurrying across the floor in some parts of the level. They appear on your motion tracker as small yellow dots. You can kill them and melee their dead bodies around.
 * It is possible to find two pieces of Cloaking equipment before you are supposed to find them on The Ark. After rescuing any marines from the barracks, get in the service elevator, fight off all of the jump pack Brutes, then, as Sergeant Johnson is fighting off the Drones, run up the staircase to the right of the Pelican. (The next wave of Brutes emerge from this door at the top of the stairs. if you go in there before the Brutes come out, by waiting by the door, they will just be standing around. They won't attack, even if you attack them, but will fire on you once they leave the corridor) Follow the path and you'll reach a control room overlooking the landing pad. Go inside and on the floor there are the two pieces of cloaking equipment. These are extremely useful when you return to the Ops Center, if you want to make an unnoticed entrance. In the same room there are two battle rifles, a regenerator, two frag grenades and a gravity lift.
 * If you go to theater mode and play a film on this level, view a part that takes place in the hangar. Take the camera out the hanger door, and down the left side of the cliff, this will take you outside the barrier. When you reach the bottom there will be a Pelican hovering just above the ground. Unlike the others in this level, you can't see inside its cockpit and the door in the back is closed. It's also possible to guide the camera into the fight between the Hornets (which have no pilots) and Banshees and to the Covenant cruiser. The Master Chief may need to be at the hanger door in order for this to work. If you get close enough to the cruiser and if seen from the right angle, you will see it is only the starboard half.
 * In the above glitch the Hornets and Banshees will disappear after a certain period has passed since they spawned, these are replaced by new ones.
 * This is the only level in Halo 3 where Commander Keyes is in view during your first person game play. In all the other levels, she will only be seen inside a drop ship, carrier or a base in some cut scenes or contact from afar through transmitting signals.
 * The Banshees and Hornets are active backgrounds items - they're not real. They lack a physical presence, you can move through them in theater mode, they have scripted deaths and the Banshees and Hornets have very low resolution textures applied to them (the front has no green shine for instance, and the Hornet's Glass is opaque). Also, a player can't destroy them due to them being background images.
 * The multiplayer map Rat's Nest is based on this level.
 * The Pelican in the hangar can be jumped through before it starts to move to where it lands. If you time it right, you can get into its bay (or even its cockpit) and stay there when it takes off. Although you will die as soon as you touch the barrier.
 * If you are playing co-op on this level, the Arbiter has a meleeing animation even if he has no weapon. If you press the melee button, (B), he will melee like an Elite. It, however, cannot hurt anyone.
 * This is the only level that features dead female marines by default; all other levels need them to die first.
 * All of the crewmen at the beginning of the level have the same voices.
 * If you have the Catch skull activated at the beginning of the level and make your allies turn against you, all the crewmen will stop working and start throwing grenades at you, even though they don't have any weapons.
 * During the cinematic, Keyes, Master Chief, Arbiter, and Johnson enter the Ops Center going through the door on the right that is locked in the beginning of the level. However, when it opens, it is a dead end.
 * If you get the Black Eye Skull before getting any weapons, if you hold down the right trigger while holding it, you will drop it, but then pick it up again, creating a dribbling illusion.
 * There are actually some ladders that lead up to bunkers and metallic "foxholes", you are able to explore them.
 * If you open the door to the Motor Pool and don't go through, the door to Ops Center will remain open. If you hold position and snipe Brutes with a Battle Rifle, you can eventually lure the Chieftain up the ramp and into the Ops Center. However, he will not attack the Marines, and vice-versa. You can even lure him down stairs, however, he will not chase you into the large cave area.
 * There is a glitch that allows you to get infinite weapons for the Motor Pool battle.
 * This is the first level where the player can use mounted turrets on all difficulty levels.
 * This is the only level that you don't start off with a weapon in the first level, unlike Halo: Combat Evolved and Halo 2. In Halo: CE and Halo 2, you are weaponless in the first levels, but in Halo 3, you are weaponless on the second level.
 * If you kill any of the marines in the Warthog when you get to the Motor Pool, the warthog will explode even before the grenade explodes.
 * In the Ops Center the small computers show displays and a diagram of the Pelican Dropship.
 * If Chief attacks at any point during the dialog between the Chieftain and Truth, Truth will disconnect and the dialog will end.
 * Cortana speaks to you throughout this level. But notice how she is saying some lines that Dr. Halsey said in the book The Fall of Reach.
 * If you kill all the drones and you reach the blast doors before the marines open it, one of them will say "Yeah, lets kick Drone ass! Oh wait, its over." or "Look, there's a big one! Oh wait, it's the Chief."
 * By dropping a Deployable Cover in the small stairway that Johnson and his Marines use to get to the landing pad, it will completely blocked off the stairway and Johnson and his Marines will cease to move, and therefore, Miranda Keyes's Pelican, along with the Arbiter will cease to takeoff.
 * The Barracks have the greatest amount of pre-spawned Marine corpses in the game.
 * There are a total of 7 Marines you can save in the Barracks.
 * Not all of the base is blown up because the level Tsavo Highway starts in the motor pool below the base.
 * If you start heading back towards the control center after you clear the hanger fast enough, the hallway with all the doors will open up a door and 3 marines will come out. If you run inside before the door closes, you'll be inside a very dark room with just more doors.
 * If you get the marines mad at the beginning of the level, you will see the non-combat personnel running around screaming at the top of their lungs. They will also aim at you as if they had a pistol but there will be nothing in their hand, yet they still have the ability to shoot you. They will also lob grenades at you, especially with the Catch skull.
 * This is the first mission with Brute Jump packs.
 * At the end of this level, where you have to get in the elevator, there will be some grunts by the elevator door who don't shoot you. If you push them into the elevator, they will run back out after a while. If you activate the elevator before the grunt can run out, he will run into the door.