Raid on High Charity

"Child of my enemy, why have you come? I offer no forgiveness; a father's sins passed to his son."

- Gravemind to John-117

The Raid on High Charity was a small, but significant engagement, between a small party of the joint UNSC-Sangheili alliance against the Flood in late 2552 on the crashed planetoid ship High Charity upon the surface of Installation 00.

Introduction
Prior to the raid, the Flood had seized the Covenant mobile home planetoid of High Charity from the divided Covenant during the Battle of Installation 05 and the onset of the Great Schism. A small UNSC force was present during the Fall of High Charity, and although many UNSC personnel fell to the Flood, SPARTAN-II supersoldier John-117 managed to escape, although the UNSC artificial intelligence Cortana was left behind during the operation.

The Flood significantly Flood-formed High Charity, initially spreading metastasizing tendrils and biological growths throughout the planetoid and cutting power while spreading spores into the air, but later, after a short period, completely remodeled the planetoid. The doors were largely replaced with biological portas and the walls were covered with infested biomass with Flood growth pods and fleshy growths. It was no longer recognizable as a Covenant installation, but rather a Flood hive. All remaining Covenant on the planetoid were killed and/or infected. Cortana surrendered to the Flood for her own safety and was tortured for information, almost succumbing.

The Gravemind, with its newly found space station and billions of Flood forms, planned to attack Earth, the UNSC/Covenant separatist stronghold, and infest it with Flood. However, upon arrival at the Sol system it found a Forerunner Portal which led from Earth to Installation 00: the Ark, a center from which all the Halo installations could be simultaneously and remotely fired. Sensing that the Ark was the greater threat, the Gravemind slipped High Charity straight to the Ark via a desperate ad hoc transit measure, sparing Earth by committing all its forces to the Ark. High Charity emerged in the fray of the Battle of Installation 00, with parts of it crashing into the Sangheili assault carrier Shadow of Intent, crippling it. High Charity then crashed onto Installation 00's surface due to damage from the Slipspace transition. While Flood exited and spread across the Ark, infesting the Citadel, large amounts of Flood still took residence within the crashed hulk.

On the Ark, however, its Foundry was manufacturing a new Halo installation to replace the lost Installation 04 which was destroyed earlier on in the year. The Covenant separatist/UNSC alliance realized that in order to contain the Flood outbreak on Installation 00 spread by the crashed High Charity, they needed to flee and then activate the Halo, sterilizing the Flood on the Ark. However, Cortana, the lost UNSC artificial intelligence still within High Charity, was the sole owner of the Index from the first Installation 04 which was necessary to fire the Halo installation. While Sergeant Major Avery J. Johnson and the Arbiter organized a systematic Separatist/UNSC withdrawal from Installation 00, John-117 ventured into the crashed High Charity via Banshee fighter to rescue Cortana, and also secure the Index to fire the incomplete Installation 04 replacement being built on the Ark.

Beginning
"Cortana's in there somewhere..."

- Sergeant Major Johnson

John-117 entered the crashed High Charity through a hole in the planetoid's surface in the western part of the station, and then proceeded inwards to the center to find Cortana. At first, he met only light resistance, with only the infection forms attacking. However, the Flood began to take notice of his intrusion, sending waves of stalker pure forms to search for him and then deploying combat forms and tank pure forms to assail him, with carrier forms lumbering behind and ranged pure forms on the walls opening fire on the SPARTAN while closer-ranged Flood attacked him directly. The strife began to intensify because of the numbers of Sangheili and Jiralhanae corpses scattered on the ground, which were easy targets for reanimation from the massive numbers of infection forms, and also because of the closely-packed claustrophobic tight quarters, whose walls were pulsing with Flood biomass.

Not long after the Flood took note of John-117's intrusion, the Gravemind began to take notice of him, contacting him in enigmatic and disorienting transmissions. At first, the Gravemind was demanding an answer as to why the Spartan had come to High Charity, wondering if John-117 "sought forgiveness" for his father's sins. After a minute, he realized that John-117 was seeking Cortana. He then began boasting that he had somehow merged with Cortana, and that together they were "two corpses in one grave." As the Master Chief forced his way deeper into High Charity and closer to Cortana, the Gravemind began getting irritated by his progress, shouting at him and making fierce threats such as "Submit! End her torment and my own!" and "You will tell me what she hides! Or I will feast upon your bones!" This was accompanied by loud growls, perhaps in an attempt to "scare" the Spartan away. Cortana began to make intense transmissions to John-117 where it appeared that she was rampant; her voice began to fracture into voices of different pitch and she adopted a chilling high-pitched giggle as she rambled in incoherent words.

However, moving his way inwards, John-117 managed to navigate a tall infested chamber, reaching the top and making it to one of High Charity's secondary reactor rooms.

Rescue
"You found me. But so much of me is wrong, out of place. You might be too late."

- Cortana

Upon reaching the next room the Master Chief encountered Cortana, who was trapped in a Stasis Field. He broke the field, finally keeping his promise to her to come back for her after he finished with the Prophet of Truth. She also still had the Index that they needed. Cortana then re-entered the Data Chip that she existed in when she was with the Master Chief, finally escaping High Charity's systems. The two then made their way back to the Reactor Room, where Cortana told the Master Chief to destroy High Charity to buy them more time to activate the replacement Halo. The Master Chief then destroyed the Reactor Pylons causing High Charity's reactor to overload. The Chief made his way through the exploding city and encountered the Arbiter, who had come to help. The Chief, Cortana, and the Arbiter escaped in a crashed but intact Pelican as High Charity's reactors detonated, destroying the city and all the Flood on it. Unfortunately, the Gravemind survived by escaping to the replacement Halo and began rebuilding itself.

List of appearances

 * Halo 3
 * Halo: Evolutions - Essential Tales of the Halo Universe
 * Human Weakness
 * Halo Mythos: A Guide to the Story of Halo