Battle for the Cartographer (Installation 00)

The Battle for the Cartographer was an engagement during the initial stages of the Battle of Installation 00 in which UNSC ground forces led by Spartan John-117 neutralized Covenant anti-aircraft defenses on the surface of the Ark, allowing the to deploy armor in order to assault a Covenant-held Cartographer facility to locate the whereabouts of the High Prophet of Truth.

Background
Following his discovery of the location of the portal that led to Installation 00 in October, 2552, the Covenant High Prophet of Regret hastily assembled a fleet of fifteen warships and, without consulting his fellow Hierarchs, took the task force to the planet on which the portal was located. This was, unbeknownst to the Prophet, the homeworld of humanity. During the battle that followed, the heavily-outnumbered Fleet of Sacred Consecration was decimated by Earth's defensive fleet and Regret was forced to flee, his performing a slipspace jump in atmosphere over the city of New Mombasa. Immediately afterwards, a larger Jiralhanae-controlled fleet sent by the Prophet of Truth arrived to take control of the battle, driving out remaining UNSC forces while beginning to excavate the long-buried portal beneath Mombasa. Over the course of the next month, the fleet would successfully uncover the artifact, and the Prophet of Truth himself would arrive on November 17, 2552 on board the Forerunner keyship Anodyne Spirit. Spartan John-117, who had stowed away on board the vessel during it's departure from High Charity amidst the chaos of the Great Schism and the city's fall to the Flood, bailed out as the keyship entered Earth's atmosphere, landing in the jungles of Tanzania. The Spartan was successfully recovered by UNSC forces. During the ensuing battle, the UNSC would destroy their local command center, Crow's Nest, to prevent its fall to the Covenant, before mobilizing for an assault on Covenant anti-aircraft defences in the city of Voi. After clearing the Covenant-held Tsavo Highway, a UNSC assault force spearheaded by John-117 pushed into Voi. While they managed to successfully destroy a number of Anti-Aircraft Wraiths as well as a Mantis Anti-Aircraft Cannon, the subsequent strike by Battle Group Victory failed to destroy the keyship and Truth successfully activated the portal. The Prophet fled through the portal along with his fleet while the UNSC were forced to deal with the arrival of the Flood-controlled Indulgence of Conviction. With the assistance of the newly-arrived Sangheili Fleet of Retribution, the Flood outbreak was contained before it could spread across the planet. After a short meeting on board the Shadow of Intent, Admiral Terrence Hood allowed the to accompany the Sangheili through the portal in pursuit of the Prophet of Truth while he remained behind to coordinate the remaining UNSC defences at Earth.

Upon their arrival at the Ark, the Prophet of Truth's fleet remained in orbit above the installation to face the human and Sangheili forces they knew would follow, while the Hierarch fortified himself within one of the Ark's superluminal communication arrays. The Prophet activated a defensive barrier around the citadel and the Ark's Foundry, while deploying large numbers of ground forces around the barrier towers maintaining the shield as well as sending a contingent of Covenant troops led by the ambitious Jiralhanae Chieftain Cethegus to a nearby Cartographer facility, in order to keep his location hidden while he prepared to activate the Halo Array and commence the Covenant's "Great Journey". On December 11, 2552, the Fleet of Retribution exited slipspace near Installation 00. Upon discovering the Prophet of Truth's numerically-superior fleet waiting for them, Fleetmaster Rtas 'Vadum confidently stated that it would be an even fight. As the opposing fleets clashed over the Ark, the deployed a force of six D77H-TCI Pelicans, one of them co-piloted by Sergeant Avery Johnson and carrying Spartan John-117 and a strike force of ODSTs from the 7th Shock Troops Battalion. Realising that Truth's ship wasn't taking part in the orbital battle, Commander Miranda Keyes surmised that he had brought the vessel down to the surface of the installation, to which Johnson replied that they would find the Prophet. As the flight of Pelicans navigated through the battling warships over the Ark, one of them was lost to strafing Seraph fighters but the other dropships succeeded in entering the installation's atmosphere.

Landing
"Priority one: secure a landing zone for the Commander's frigate. Keep your eyes and ears open. We need all the intel we can get... on wherever the hell we are."

- Sergeant Avery Johnson reminding the strike team of their objective.

As Kilo 023, containing John-117 and his strike team flew in low over Installation 00's vast desert, Sergeant Johnson told the strike team that their immediate priority was to secure a landing zone suitable for the Forward Unto Dawn to deploy UNSC armor onto the Ark's surface. Johnson also told them to be on the lookout for any sources of information that could help them learn more about the installation as they went. The Pelicans arrived at a cliff edge, and John-117, armed with a sniper rifle and the ODSTs deployed to the surface while another Pelican dropped off several more ODSTs. As the team moved forward, one of the ODSTs spotted the Milky Way galaxy in the sky and expressed his amazement before their squad leader told him to focus on their current task. The team came upon a Covenant encampment, where a group of Unggoy, Kig-Yar and Jiralhanae were listening to a holographic projection of the Prophet of Truth, who was explaining that his ship was unable to participate in the orbital battle, while urging his loyal troops to destroy the Sangheili fleet. As the team took up positions on a ledge overlooking the encampment, the squad leader told John to take the first shot with his sniper. John quickly set his sights on one of the gathered Covenant soldiers and fired, with the ODSTs following suit. Catching the Covenant off guard, the strike team were able to effectively whittle down their numbers. Additional infantry arrived from a nearby cave while several Unggoy Heavies attempted to use plasma cannons mounted on a deployable lookout tower to suppress the UNSC forces but eventually all of the Covenant soldiers fell. With the area secure, the ODST squad leader reported that there was more enemy contacts on the other side of the cave. The team arrived at the next encampment where the Covenant were in the process of constructing a Mantis Anti-Aircraft Cannon. Recognising the grave threat that the emplacement would pose to the Forward Unto Dawn were it to be completed, the strike team opted to prevent this. The squad leader again told John to take the first shot. As the battle began, the Phantom that was assembling the emplacement dropped it's component pieces and fled. As the battle turned against the Covenant's favor, a second Phantom arrived, deploying a Mgalekgolo pair, who charged forward while the surviving Covenant forces retreated from the encampment. After a struggle, the strike team were able to eliminate the Covenant gestalts, before finishing off the remaining infantry in the nearby rocks. The team ascended up a nearby ridge, where a final group of Unggoy led by a Jiralhanae Captain attempted to stop them but failed. Commander Keyes reported that the Forward Unto Dawn was heavily outmatched by the Covenant vessels over the Ark and told John that finding a landing zone for the frigate was their priority. As the team moved through a small corridor in the cliff wall, John took a small detour, where he accessed the Forerunner terminal network for the first time. On the other side of the cliff, the team discovered several Marine survivors from a nearby downed Pelican. A flaming Longsword roared through the ravine, crashing ahead of the team's position. One of the Marines from the Pelican reported that Covenant anti-aircraft fire had brought down their dropship, but they had managed to spot an area suitable for the Forward Unto Dawn to land before they had crashed. The group moved forward to a small ledge overlooking the Marine's downed Pelican which was currently being searched by a Covenant lance. While the Marine's Warthog had been destroyed, a pair of nearby Mongooses were still intact and able to be used. The team ambushed the Covenant forces at the Pelican and quickly took them out. Their reprieve was short-lived, as two Jiralhanae Prowlers arrived, one of them disgorging its occupants while the other circled the area, using its plasma cannon to pin the humans down. Despite this, the UNSC forces were able to neutralize the Prowlers and moved down to the Pelican wreckage, where they were able to scavenge ammunition while overhearing snippets from the ongoing space battle above them. The team mounted up on the available vehicles and rolled into the next valley where the Longsword had gone down. The crash site was patrolled by Covenant infantry and vehicles including several Choppers and Ghosts. The now mobilized UNSC forces were able to crush the Covenant opposition and move past the crash site as well as an overturned Warthog and several vacant SOEIVs whose occupants had been killed shortly after landing. The team wiped out a small group of Unggoy near a crashed Phantom in the next area and overheard more reports from the orbital battle, this time from a Jiralhanae fleet commander. In the larger area beyond the downed Phantom the team discovered a large Forerunner wall where the Covenant were under attack by the Ark's Sentinel defenders. John-117 and his strike force fought past several Choppers and a Covenant position reinforced by defense barriers and onto the upper level of the wall where they assisted the Sentinels in finishing off the remaining Covenant forces. While the strike team were anxious about the Sentinel's presence, the Forerunner constructs didn't fire on the humans. Kilo 023 arrived, with Sergeant Johnson reporting that they had spotted a structure beyond the wall that matched Cortana's reports of the Cartographer facility on Installation 04. Commander Keyes told them that they would push through the wall once they had secured a landing zone for the Forward Unto Dawn, and Johnson opted to lead the strike team to the landing zone, telling them to follow Kilo 023. As the team made their way towards the landing zone, they were attacked by several Unggoy-piloted Ghosts under a large overhang before arriving at the cave entrance leading to the LZ, where several Marines were pinned down near their destroyed vehicles by encroaching Covenant forces. After the area was secure, the Marines reported that the landing zone was heavily occupied by Covenant armor. With this, the strike team moved through the cave, emerging into the open area which was occupied by a Type-26 Wraith, a brace of Ghosts, numerous plasma cannons and a pair of deployable lookout towers. Further back was a pair of Anti-Aircraft Wraiths that would need to be destroyed to allow the Forward Unto Dawn to land safely. Despite the heavy Covenant presence, John-117 and the ODSTs successfully destroyed the Covenant armor protecting the Anti-Aircraft Wraiths, before wiping out a final Jiralhanae pack and the Wraiths. With the area now secure, Commander Keyes brought the Forward Unto Dawn into the landing zone. The team were forced to take cover as the frigate's arrival sent debris from the battle scattering across the area. Having arrived safely, The Dawn lowered it's hangar, deploying a trio of Scorpion tanks and a Warthog along with 343 Guilty Spark while Marine reinforcements arrived on Kilo 023. The surviving ODSTs from the Master Chief's strike team proceeded to board the Pelican.

UNSC armor is deployed
"Commander Miranda Keyes"

- Sergeant Avery Johnson

As the UNSC armor fanned out from the Forward Unto Dawn's hangar bay and a unit of Marines led by Gunnery Sergeant Marcus Stacker assembled to mount the vehicles, Sergeant Johnson reported that the Sangheili had located the Cartographer. The facility lay on the other side of the wall that John and his strike team had cleared, but the building was protected by a battalion-sized unit of Covenant heavy armor. Commander Keyes replied that they would use their own armor to push through the wall and confront the Covenant head on. 343 Guilty Spark told them that he would do his best to unlock any doors that obstructed the convoy, despite his unfamiliarity with Installation 00 and its security systems. John commandeered one of the vehicles just as a unit of Ghosts and a Prowler entered from the nearby cave, killing the Marines guarding it. The Covenant had re-deployed forces on the path leading to the wall, hoping to stop the UNSC from reaching the Cartographer. The convoy moved forward, destroying the Covenant vehicles that had arrived in the area. A Mgalekgolo pair then emerged from the cave, but were easily taken down by the Scorpion tanks. As the Marines expressed glee at their heavy firepower, the convoy rolled through the cave. On the other side, they managed to destroy a Phantom that was in the process of deploying infantry and Shade turrets. Under the next overhang, a larger unit of Ghosts and a single Wraith blocked the UNSC's path while another deployable lookout tower carrying infantry was stationed at the top of the rise. Ultimately, the humans were successful in defeating the Covenant forces and made it into the area where the wall was located. The Covenant had deployed large numbers of forces to protect the wall, including several Wraiths, Choppers and numerous Shades. A Phantom delivered another Wraith in front of the locked door on the upper level of the wall when the Covenant presence began to wane. Stacker had the convoy form up at the lower level while John proceeded along the upper floor with 343 Guilty Spark. After the area was clear, 343 Guilty Spark opened up the door on the upper level, imploring the humans to avoid collateral damage to the installation. With the way now open, John proceeded inside while the rest of the convoy entered the wall through the lower door. After opening up another door inside the wall, Spark led John to a panel overlooking a deep chasm. Spark informed John that the panel would activate a light bridge that would allow the convoy to cross the chasm below. After activating the bridge, John discovered another terminal console. As the Spartan made his way through the wall, passing by several destroyed Sentinels, he felt the building shake as a Covenant Type-47B Scarab made its way over the wall. As John emerged from the wall, the assault platform made its way past him out into the desert. He observed several Warthogs leaving the wall's lower level only to get destroyed by the numerous Wraiths in the immediate vicinity. A Gauss Warthog made its way up to his location, strafed by several Ghosts which killed the gunner. The driver dismounted next to John, offering the Spartan the controls. The Spartan made his way down towards the lower level while the gunner destroyed a number of Ghosts as well as a position consisting of Unggoy and Kig-Yar infantry. As they arrived at the wall, the Scorpion tanks emerged and began to trade fire with the Wraiths and Choppers in the area. Gunnery Sergeant Stacker, operating one of the tanks, led the UNSC forces as they clashed with several lines of Wraiths and Ghosts. At the second line, a Phantom deployed a team of fuel rod gun-wielding Jiralhanae troops in an effort to destroy the Scorpions but the Brutes were soon taken out. The Scarab eventually returned, clambering down from the Cartographer building into the battlefield. With the help of Stacker and his armoured column, John-117 was able to destroy the Scarab, igniting an explosion that was noticed by Rtas 'Vadum in orbit. 'Vadum reported that his fleet had triumphed over the Jiralhanae, leaving the Covenant ground forces on the Ark stranded and without reinforcements. As the Shadow of Intent entered the atmosphere, 'Vadum expressed his desire for revenge on the Prophet once his location was discovered. A number of Marines dismounted from their vehicles, assisting John as he pushed his way up the ramps of the Cartographer building, engaging several groups of Covenant infantry as they went. On the top of the spire, Kilo 023 arrived, carrying Arbiter Thel 'Vadam and a pair of Marines. Spark arrived, unsealing the entrance to the facility, allowing John, Thel and the Marines to enter.

The Cartographer
"John-117"

- 343 Guilty Spark

In the foyer of the facility, Spark attempted to open a sealed door ran into trouble unlocking it. One of the Marines with the group offered to assist, but when he moved up to the door, Spark shocked him with his small energy beam, causing the Marine to yelp in pain. While the rest of the team reacted with shock and readied their weaponry, Spark explained that he didn't want the Marine to come to harm. Eventually the monitor succeeded in opening the door, revealing a room full of sleeping Unggoy and a Jiralhanae urinating in the corner. Thel expressed disdain at the slumbering Covenant troops and told John to take them out silently. The Spartan made quick work of the Covenant in the room, killing them all before they could raise an alarm. Following Spark's lead, the group made their way through the facility, making their way down to the level where the Carotgrapher terminal was located. The group managed to take out another group of unwary Covenant in the next large room while John accessed another Forerunner terminal console in the small room nearby. The team's cover was blown as they reached the level where the console was located, as a Jiralhanae soldier opened the door as the group approached. John, Thel and the Marines managed to eliminate the Jiralhanae pack and their Kig-Yar support guarding the Cartographer. The two Marines remained in the room to guard it while the Spartan and Sangheili moved on to the Cartographer. John accessed the console, expressing surprise regarding the installation's location beyond the rim of the Milky Way galaxy. 343 Guilty Spark confirmed to the Master Chief that the installation was indeed the Ark. Spark was surprised to learn that the Ark was not a shield world as he had expected, explaining that his creators had compartmentalized his knowledge of other installations besides his own Halo ring, in case he was captured by the Flood. The monitor pinpointed the Prophet of Truth's location: a facility near the Ark's Foundry, before informing them of the energy barrier he had erected around the core. Spark then realized that a replacement Halo for the destroyed Installation 04 was being created inside the Foundry but before the monitor could say anything, a Covenant Phantom arrived near the console. As Thel engaged the dropship's gunner from the ground, John managed to get Spark to move out of the line of fire. With newfound urgency, Spark told John that they needed to get past the barrier around the Ark's core, before Truth wiped everything out, including the newly-created replacement for his lost Halo ring. Sergeant Johnson radioed John, warning him of a large group of Covenant aircraft approaching his position, telling him to get back into the facility while the UNSC air forces took them out. At this time, the ambitious Jiralhanae Chieftain Cethegus became aware of the Spartan's intrusion and was charged with halting his progress by the Prophet of Truth. Seeking to claim the title of Chieftain of the Jiralhanae after it's previous holder was slain in battle by the Arbiter, Cethegus knew that he would surely be granted this honor should he kill the "Demon". Meanwhile, John made his way back into the facility while Thel boarded a nearby Banshee, killing it's Jiralhanae pilot and taking the aircraft to help Johnson deal with the Covenant reinforcements. As one of the Marines told John that Kilo 023 would land to extract them on the level below their current position, the other Marine was killed by plasma grenades thrown by Unggoy soldiers. John and the remaining Marine made their way into the room, quickly avenging the fallen UNSC soldier before engaging more Jiralhanae forces led by a War Chieftain while 343 Guilty Spark pondered the creation of a possible replacement for Installation 04 but refusing to jump to conclusions. John reached the lower level, where the room was empty save for Cethegus on the lower level. The Chieftain taunted the Spartan before retreating out of the room. John was then attacked by a number of Stalkers left to deal with him while Cethegus regrouped with his flight-fighters on an exterior platform. John managed to defeat the camouflaged Jiralhanae and their Kig-Yar backup before making his way outside to where Cethegus and his pack waited. A holographic projection of the Prophet of Truth instructed Cethegus to best John in combat by himself, or he would be left behind on the Covenant's "Great Journey". With the Prophet's words ringing in his ear and inspired by his pack's frenzied roars, Cethegus activated his gravity hammer and challenged the Spartan. The two then begun battle while the Jiralhanae Jumpers waited on the edge of the platform. John successfully managed to kill the Chieftain, resulting in his pack-mates and a pair of Kig-Yar marksmen attempting to avenge their fallen commander but they too were defeated by John. With the platform now secure and the Covenant presence in the air neutralized, Kilo 023 arrived to pick up the Spartan. Before the Chief could board the dropship, they were caught by surprise by a massive flock of Sentinels rising up from below. As Sergeant Johnson spun the Pelican's bay-mounted heavy machine gun in anticipation of a fight, Spark cautioned him not to fire, explaining that the constructs were instead leaving to fulfill a separate task elsewhere on the installation but he was unable to explain the nature of the task. Although Spark wanted to find a terminal closer to the Ark's core to learn more about Cortana's purported "solution" to the Flood threat, Commander Keyes and Thel 'Vadam told him that their priority was stopping the Prophet of Truth from activating the Halo Array, and that until this was completed, they could not concern themselves with anything else. With his objective completed, John boarded Kilo 023 and the Pelican left the Cartographer.

Aftermath
After successfully discerning the Prophet of Truth's location and aware of the heavy array of defenses the Hierarch had placed around the Citadel, the UNSC and Sangheili launched a joint assault on a trio of barrier towers; having learned from 343 Guilty Spark that this would be enough to drop a section of the shield and allow the Shadow of Intent to destroy the Citadel. While they were successful in deactivating the towers, Sergeant Johnson was captured by the Covenant and brought to the Citadel to be used by Truth to activate the Array due to his status as a "Reclaimer" and the Shadow of Intent was damaged by debris from the Flood-infested High Charity, which arrived during the battle, forcing the UNSC/Sangheili alliance to begin a ground assault on the Citadel. Ultimately, they would destroy all Covenant opposition in front of the Citadel and a team consisting of John-117, Thel 'Vadam and several Sangheili would storm the Citadel's interior, forming a brief alliance of the Flood to destroy the last vestiges of Covenant resistance and make their way to Truth, but were too late to stop Commander Keyes' death at the Prophet's hand and the beginning of the activation process. Eventually, the Prophet of Truth would meet his death at the hand of Thel 'Vadam and John-117 would halt the activation of the Array, resulting in the fragmentation of the Covenant.

After learning of the existence of Installation 08 and recognizing it as the "solution" to the Flood Cortana had mentioned in the message he had retrieved from the Indulgence of Conviction on Earth, John ventured alone into the remains of High Charity to retrieve his missing AI companion while the UNSC and Sangheili command coordinated the departure of their forces from the Ark. John eventually retrieved Cortana from deep within the Flood hive and escaped on a Pelican with the help of Thel 'Vadam. While the Shadow of Intent left Installation 00 with surviving UNSC and Sangheili personnel on board, John, Thel, Cortana and Sergeant Johnson made their way to the control room of Installation 08 with the objective of firing the incomplete Halo ring to destroy the Flood presence on the Ark using the Activation Index that she had kept from Installation 04. While 343 Guilty Spark ultimately succumbed to Rampancy and mortally wounded Sergeant Johnson, John successfully started the Halo's activation sequence and he and Thel fled for the nearby Forward Unto Dawn on Johnson's Warthog. They would successfully escape into slipspace while the installation fired, wiping out the majority of the remaining Flood on both the Halo ring and the nearby Ark. Unfortunately, the Forward Unto Dawn was sheared in half during it's escape, as the slipspace portal collapsed as the ring fired. The forward half, containing Thel 'Vadam successfully arrived at Earth while the rear section containing John-117 and Cortana fell out of slipspace in an unknown part of space, eventually arriving at the Forerunner shield world Requiem four years later.

List of appearances

 * Halo 3