The Ark is the seventh campaign level of Halo 3. It takes place in a desert that comprises one of the center-most regions of the Ark, located 218 light-years outside the Milky Way galaxy's center. In this level, the Sangheili and the humans side with 343 Guilty Spark and his Sentinel allies to access the Cartographer and find The Prophet of Truth. Beating this mission on Heroic unlocks the shoulder pauldrons to the Elite Flight Harness armor permutation. Beating this level on Normal unlocks the EVA-class Mjolnir shoulder pads. Beating this level on Legendary gets you the EOD-class Mjolnir shoulder pads. Getting more than 50,000 Meta Game points will unlock the Ranger achievement, worth 10 Gamerscore.
The joint UNSC-Sangheili fleet crosses the Portal and arrives in orbit over a massive Forerunner structure. While Commander Miranda Keyes and Shipmaster Rtas 'Vadum engage Truth's much larger fleet, John-117 and a contingent of Marines and ODSTs are deployed to the surface of the Forerunner structure. Upon landing, John-117 and a team of ODSTs head out on foot and clear out two large Covenant-held positions and stop the Jiralhanae from setting up an anti-aircraft battery. Keyes orders the Master Chief to clear a landing zone for the UNSC Forward Unto Dawn.
The Chief and the ODSTs meet up with a group of Marines whose Pelican was shot down. The Marines inform the Chief that there's a good landing zone for the Forward Unto Dawn nearby. After retaking the Pelican crash site, John-117 and his allies commandeer an assortment of vehicles and drive off to secure the LZ. Along the way, the Chief discovers a large Forerunner wall built between the cliffs. The entrance to the wall is guarded by Sentinels which attack the Covenant but leave the humans alone. Johnson arrives in a Pelican and informs Commander Keyes that Hocus has found a structure located on the other side of the wall. Keyes deduces it's a Cartographer which they can use to locate the Prophet of Truth.
The Chief arrives at the Forward Unto Dawn's intended landing zone and defeats the Covenant forces occupying it including a pair of Anti-Air Wraiths. With the landing zone secure, the Forward Unto Dawn enters the installation's atmosphere and deploys reinforcements, including Scorpion tanks. Keyes orders the Master Chief to take the convoy through the wall and locate the Cartographer. John-117 takes a tank and leads the armored convoy against a large force of Covenant vehicles and infantry. 343 Guilty Spark accompanies the humans and opens the entrance to the wall, allowing John-117 to enter on foot. Inside, he activates a light bridge, allowing the UNSC convoy to pass through the wall.
Upon reaching the other side, the UNSC encounters another large force of Covenant vehicles, including a Scarab, guarding the structure containing the Cartographer. After a prolonged battle, the Chief and his allies prevail. At the same time, Shipmaster 'Vadum reports that Truth's fleet has been defeated. The Chief heads up to the top of the structure, where he teams up with Thel 'Vadam and a pair of Marines. 343 Guilty Spark opens the doors, allowing the Chief and his allies to enter. The group fights their way into the lower depths of the building and finally locate the Cartographer. Upon accessing the Cartographer, John-117 discovers that they are outside the Milky Way galaxy, and that this installation is, in fact, the real Ark. Guilty Spark locates the Prophet of Truth, who has activated a protective barrier around himself. Spark then discovers something else, but before he can reveal what it is, a hostile Phantom arrives. Johnson contacts the Chief and warns him that additional Covenant forces are heading their way. Thel 'Vadam hijacks a Banshee and engages the Phantom, while the Chief and the Marines head to the lower level to meet up with their evac. After defeating more Covenant troops, including a Jiralhanae Chieftain, the Chief is picked up by Johnson's Pelican. As they leave, a massive force of Sentinels are seen departing on an unknown priority mission. Though Guilty Spark wants to focus on finding Cortana's solution to the Flood, Commander Keyes states that they must stop the Prophet of Truth first.
Cut to the bridge of the Shadow of Intent.
Hocus nods, and presses a button on the controls. The Pelican drops out of the UNSC Forward Unto Dawn along with six other Pelicans. The massive underside of the Shadow of Intent can be seen flying on top of the Forward Unto Dawn, which is seen leaving the Shadow of Intent's underside. As the dropships breach through the Covenant fleet, one of the Pelicans takes a hit from a Kai-pattern Seraph fighter-interceptor. Its starboard engine bursts into flame and it spirals out of control and explodes. The other Pelicans make it through unscathed. As they enter the atmosphere, the Chief checks on Johnson and Hocus in the cockpit, then returns to the back, where several Marines and ODSTs sit, readying themselves for battle.
The Master Chief picks up a sniper rifle holstered in the troop bay.
The Master Chief slams a magazine into his rifle. The troop bay hatch opens, revealing a massive desert (In Co-op, the Arbiter, with a Type-50 particle beam rifle, stands up from the right side of the troop bay and moves to sit on the left side). The Chief walks to the right side and sits down.
The Pelicans touch down on a cliff side.
The Master Chief (and the Arbiter, in co-op) and two ODSTs jump out of the Pelican. The Marines remain on-board. Another Pelican lands, dropping off two more troopers (In 3-4 player Co-op, N'tho 'Sraom and Usze 'Taham will come from the second Pelican). As the team moves on, one spots what looks like a galaxy in the sky.
The Marines take up positions on a ledge, overlooking a Covenant encampment.
An ODST with red armor trim (Squad Leader) turns to the Chief.
The ODST leads the team up the hill.
The team sets up firing positions.
The Chief fires, and the rest of the team opens fire. Through tactical advantage and sniper fire, the enemy soldiers are wiped out. The team continues on.
The team engages the enemy. The Phantom abandons a piece of the battery and flees. Having the lower ground, the Covenant soldiers start to retreat. Another Phantom drops off a Mgalekgolo pair. The Master Chief finally takes them down, and the team continues up the hill, engaging a large group of Unggoy and a Jiralhanae Captain.
If the player stalls:
If the player continues to stall:
The Master Chief and the team head through the structure at the top of the hill. Coming out on the other side of the structure, they see a burning Longsword roar through the canyon.
A muffled rumble is heard a few seconds later.
A few Marines reveal themselves.
The Chief and the others look at an area at the bottom of the ledge they are standing on. Several Unggoy and Jiralhanae are guarding a crashed Pelican and Mongooses which presumably fell out when the Pelican was shot down. The Chief and his allies engage the Covenant patrol and annihilate them.
If Chief stays by the downed Pelican he can pick up radio transmissions of the ongoing space battles above the installation.
Two Brute Prowlers show up. One parks near the Mongooses and its Jiralhanae occupants all leap out while the other circles the area, firing at the UNSC forces. Once the Jiralhanae are all killed, the Marines mount up on the Prowlers and working Mongooses.
The team continues on, wiping out a small group of Covenant camped around a crashed Phantom. Transmissions from Jiralhanae warships can be heard from the Phantom.
The assault team heads into another canyon with a large Forerunner wall built in between the cliffs. Fighting their way through a large enemy force, the team makes it to the higher level, where Covenant troops are engaged with Aggressor Sentinels.
The UNSC forces and the Sentinels clear the top floor. The Sentinels don't open fire on the humans. Johnson's Pelican flies over the wall and hovers.
The Sentinels follow Hocus' Pelican. The Marines are nervous about their presence.
The team and the Sentinels continue along the other canyon, towards the LZ. Wiping out a pair of Ghosts under a large Forerunner structure, the force presses on. Near a cave, they find two Marines pinned down by a large assault group of Covenant, including another pair of Ghosts (on higher difficulties, a Jiralhanae wielding a fuel rod gun is also present). The Sentinels and the Marines clear the area. The UNSC forces meet up with the two Marines.
The team heads through the cave. A large Covenant force is encamped in the next area, including a Wraith, a brace of Ghosts, Jiralhanae and Unggoy-operated turrets. After a struggle, the team eventually prevails. Out on a sandy plateau, two Anti-Air Wraiths are filling the sky with fuel rod fire. The team takes out the Anti-Air Wraiths and any remaining Covenant.
The UNSC Forward Unto Dawn swoops in dramatically, kicking up dust and sending the vehicles and debris from the previous battle tumbling and flying across the plateau.
Forward Unto Dawn
If the player is away from the back:
If the player skipped the wall section leading to the Cartographer:
The tanks and Warthog leave the hangar bay, and Johnson's Pelican drops off Gunnery Sergeant Stacker and a few of his Marines to commandeer the vehicles. Any surviving ODSTs from the first part of the level will board the Pelican.
The Monitor hovers near one of the Scorpions.
The player chooses a vehicle while the rest of the Marines mount up.
The convoy starts to move out.
After the convoy scores a kill:
The convoy destroys all hostile vehicles.
A Mgalekgolo pair charge out of the cave. The UNSC forces destroy them with little effort.
The convoy makes its way back to the wall where a locked door prevents any entry into the Forerunner facility. Armor resistance in the form of Wraiths, Choppers, and Ghosts along with various Covenant infantry defend it.
The Chief and the Marines attack the facility's upper level.
If the player waits:
If the player still doesn't follow 343 Guilty Spark:
While the Master Chief storms the upper level, the other two tanks and other vehicles meet up at the lower door, clearing any resistance along the way. The Chief secures the top floor. 343 Guilty Spark arrives on the scene.
Guilty Spark opens the door.
If the player goes back to the bottom of the wall:
The Chief hops out of the Scorpion and follows Guilty Spark into the Security Wall. The Marines take the Scorpion down to the lower doorway.
Inside the structure, the Chief encounters a Sentinel. It stares at him as he passes by. The Monitor opens another door; the escorting Sentinel follows. Spark leads the Chief to a platform overlooking a deep chasm. The UNSC forces have gathered below on the left side of the chasm, and are waiting to cross.
Spark shows the Chief a control panel at the edge of the platform.
If the player stalls:
If the player still waits:
The Master Chief activates the panel. The bridge immediately lights up. The tanks and Warthogs move across; Guilty Spark opens another door. The Terminal behind the Chief is now accessible.
Guilty Spark looks at the Sentinels, studying their differences in behavior and the odd high security levels.
As the Chief continues on, the building shakes violently. Guilty Spark opens a door leading outside.
As the Chief walks out, a massive leg slams down as a Scarab walks right over him.
A Warthog with an M68 Gauss Cannon appears from the rocky area. Pursuing Ghosts kill the Gunner. The Warthog driver finds the Chief and pulls over. In the distance, two other Warthogs have already engaged the Covenant heavy armor (they are usually destroyed before the Chief can help them).
The Master Chief mounts up. The Warthog heads back down through the rocky area, encountering more Ghosts, infantry and gun emplacements. They break through, enabling the Scorpions to begin their assault.
The Scorpions emerge from the wall.
The UNSC forces push down the hill. Hostile Wraiths, Choppers, Ghosts and a Phantom engage the Platoon.
The tanks and the Chief take out the first two Wraiths.
The tanks move on to the next line of Wraiths, which are assisted by Ghosts and other heavy units. The UNSC forces clear them out.
The Scarab crawls down the side of the Cartographer building and onto the battlefield.
If the player stalls:
If the player continues to stall:
If the player still continues to stall:
If the player still doesn't take down the Scarab:
The Chief moves in on the Scarab. The tanks provide long range cover fire. Choppers try to assist the Scarab, but the tanks have superior firepower. The Chief can either jump onto the Scarab using the canyon's natural terrain, or damage a leg forcing the Scarab to lower itself.
The Chief boards the Scarab:
A sermon broadcast by Truth can be heard inside the Scarab:
A group of Kig-Yar, including several marksmen, as well as a Jiralhanae Captain and several Unggoy try to stop the Chief's progress. The Spartan eliminates them and goes to the back of the Scarab and destroys its core, then flees before the Scarab detonates in a deafening explosion. The Shadow of Intent can be seen entering the atmosphere at extreme distance.
Alternatively, the Chief can target the power core on the Scarab from the ground with the main cannon on a Scorpion after taking out its legs. The Chief first has to blast off a massive plate covering the area with the power core, but once it is gone, just a few shots to the power core from the Scorpion's main cannon will overload it and destroy the Scarab.
Once all remaining hostiles in the immediate area have been neutralized:
The Chief heads up the spire.
The Chief and the remaining Marines clear out the Covenant infantry on the spire. The Marines hold position.
If the player stalls:
The Chief makes it to the top, where Pelican Kilo 023 arrives with the Arbiter and two Marines. 343 Guilty Spark is also present.
Spark opens the entrance door. The team enters the facility.
Real Men Don't Read Maps
Bang and clear.
The team enters a small room littered with Unggoy corpses and Sentinel wreckage leftover from a previous battle. 343 Guilty Spark starts to open the next door, but has trouble unlocking it.
When the Marine approaches, Guilty Spark faces the Marine and fires a blue laser at him. He yelps in pain and jumps back.
'Vadam raises his weapon and walks around Guilty Spark cautiously just in case Spark becomes rampant.
Guilty Spark gets back to work. He succeeds.
Unggoy are sleeping while a Jiralhanae Captain is urinating in a corner of the room. The team decides to take a stealthy approach.
They stealthily take out the sleeping Unggoy patrol and the Jiralhanae urinating against the wall. (Alternatively, they can just shoot as normal).
If the player remains inside the room and stalls:
If the player comes close to the room where the terminal is you can hear 343 Guilty Spark say a few lines from it. If anyone enters the room or 343 Guilty Spark is hit, he will stop talking.
The team quietly makes their way down to the second part of the facility; the Chief encounters an Unggoy patrolling next to a stack of plasma batteries. He eliminates it, and proceeds into the next room where a group of Unggoy are sleeping and a Jiralhanae is patrolling a ramp at the top of the room. The team kills the Covenant troops, quietly or not.
On the third level down, a Jiralhanae spots them and the team is forced to engage. After clearing out the Jiralhanae and Kig-Yar inside, the team heads outside to a large platform in front of a waterfall. A terminal to the Cartographer sits at the ledge.
If the player hesitates
The Arbiter and the Marines keep watch, while the Master Chief activates the Cartographer.
Upon activating the Cartographer, a holographic projection of the Milky Way appears. A small dot outside the Milky Way is labelled.
The hologram zooms in to the small dot, which changes to a map of Installation 00.
Spark flies away from the console, to the top of the holographic map.
Guilty Spark turns around and looks at the Master Chief.
A specific area on the hologram is highlighted.
In the distance, two Covenant Banshees can be seen flying by the Cartographer. 'Vadam gives the Chief a concerned glance. The Master Chief walks further around.
Guilty Spark notices the enormous ring, highlighted in purple, surrounding the Ark's core.
Before Spark can answer, a Covenant Phantom approaches.
The Arbiter and the Chief get into position to engage the approaching Covenant ship as 343 Guilty Spark continues to hover over the map, deep in thought.
The Monitor finally notices the Phantom and flies towards the Chief as 'Vadam engages the Covenant ship from the ground. The Phantom's side gunner returns fire.
A Banshee makes a slow attack run on 'Vadam.
The Arbiter boards the Banshee, kills the Jiralhanae pilot and takes control.
'Vadam intercepts the Phantom (if not destroyed by the Chief), which breaks off and retreats. The Arbiter gives chase in his Banshee. The Chief returns to the entrance to the room, and a Marine approaches him.
As the Chief heads back into the room, there is a possibility that the female Marine guarding the door will get killed by a plasma grenade. Covenant reinforcements, led by a Jiralhanae War Chieftain wielding a detached plasma cannon, enter the room. While the Chief and the others fight, 343 Guilty Spark talks to himself about the original Halo.
The Chief and any surviving Marines clear out the Covenant attackers. They exit the room and head downward. Jiralhanae Chieftain Cethegus is waiting for them on the bottom floor of the lower level, wielding a gravity hammer.
The Chieftain runs off outside, leaving a pack of Jiralhanae Stalkers to deal with the Chief. The Stalkers deploy a radar jammer and engage the Chief, but he eliminates them all. A pair of Kig-Yar enter the room, and the Chief quickly kills them too.
The Chief goes outside, where he finds Cethegus conferring with the Prophet of Truth via a holo-pedestal. Jiralhanae Jumpers gather around Cethegus. Truth orders Cethegus alone to take out the Chief.
Truth terminates communications. Cethegus charges the Master Chief, while the other Jiralhanae hold back, observing the fight.
The Chief eliminates Cethegus. The Jiralhanae Jumpers and two Kig-Yar sharpshooters spring into action. The Chief takes them down while the Marines provide long range cover fire.
Once all hostiles are neutralized:
The Chief and the Marines meet up with the Pelicans.
As Johnson's Pelican arrives to pick up the Chief (and the Arbiter in Co-op), a massive flock of Sentinels rise up. Alarmed, the Chief raises his weapon.
A Sentinel comes up to the Chief and inspects him. The Arbiter interrupts Guilty Spark.
The Sentinel closes back up and rejoins the flock.
The Chief boards the Pelican. (In Co-op, 'Vadam will join him.)
The flock of Sentinels speeds off, with the Pelicans in trail. Fade to black.