Fall of High Charity

The Battle of High Charity was a large battle for control of the Covenant Capital, High Charity. The battle was significant in that it was the start of the Covenant Civil War, and contained hunts for both the Index by Spartan-117 and the Flood Invasion of High Charity

The fracturing of the Covenant
The Battle of High Charity was one that would have happened eventually, for it was the point of origin for the Covenant Civil War. With the Brutes slowly gaining the favor of the Prophets over the Elites, it was only a matter of time before the actual split would happen.

This was further helped along by the Changing of the Guard, giving the Brutes the position of being the personal protectors of the Prophets, and the failing to protect both Installation 04 (Alpha Halo) and the Prophet of Regret.

Battle of Installation 05
However, while the eventuality of the Battle of High Charity was a foregone conclusion, its scale was not. The Prophet of Regret's wayward mission to Earth brought High Charity, Spartan-117 and In Amber Clad near Installation 05. With the Gravemind already released and plotting its way off of the Halo, this would set the tables for the invasion by both the Flood and the legendary "Demon".

The final piece of the puzzle in the battle was when Tartarus took the Sacred Icon from the Arbiter and subsequently attempted to execute the latter.

Gravemind
The Arbiter, however, would not be slain there. The Gravemind had other plans for him along with Spartan-117. Realizing that the Index, now in the hands of the Covenant who fully intended to fire the Halos, would result in his death, the Gravemind saved both of their lives from being killed so that they could aid him in finding and recovering the Index. With two plausible locations for the Index being High Charity with the Prophets and the Control Room on Halo, he send Spartan-117 to the former and Arbiter to the latter.

Master Chief's Entrance
The battle began in the Council Chamber. The Prophet of Truth (with the Prophet of Mercy) was giving a speech to the Covenant commenting on the release of the flood and announcing Tartarus' successful acquirement of the Sacred Icon. As he drew his speech to a close, Spartan-117 was teleported into the room, standing right beside the grunt who was filming the speech. He acquired the Grunt's weapon and aimed it at the Prophets, but the Brutes covered the Prophets so they could escape.

Once he secured the Council Chamber, Spartan-117 inserted Cortana into High Charity's so she could open the doors. She then opted to remain in High Charity's system as she felt it would provide her the greatest opportunity to aid him. The Spartan then began chasing the Prophet of Truth

Rescue
Shortly after beginning his hunt, Cortana noted that there were Marine transponders near the Master Chief's position. Realizing that they could aid in the hunt, Cortana directed the Spartan to the prison where he rescued over half a dozen marines.

The Covenant Civil War Begins
Soon after rescuing the marines, the Prophet of Truth declared that the Brutes were now in charge of the fleets. The Elites were infuriated by this pronouncement and began fighting their bitter rivals, starting the Covenant Civil War. As Spartan-117 and his marines moved around High Charity, they bore first-hand witness to the fracturing of the Covenant, sometimes opting to watch the two sides fight rather than becoming directly involved.

Enter: The Flood
Sometime later, In Amber Clad entered High Charity via Slipspace and crashed into a tower inside the structure. Cortana tried to contact the ship but registered no life signs on board. It would be a while before the true nature of In Amber Clad's arrival would be known, for she had been captured by the Flood. The various short range craft she contained launched and spread the Flood throughout the city, allowing them to quickly spread and attack the warring parties throughout High Charity.

Mercy Falls
In the race to capture the Index, Spartan-117 lost. The Prophet of Truth made it to Tartarus' location and handed him the Index. Tartarus prepared to take the Index along with [UNSC prisoners Commander Miranda Keyes and Master Sergeant Avery Johnson to Installation 05 to activate it.

Before they could leave, however, Flood Infection Forms attacked them. Tartarus and his brutes tried to defend the Prophets of Truth and Mercy, but one of the Infection Forms got through their screen and landed on Mercy. Tartarus moved to remove the Infection Form, but the Prophet of Truth ordered him to let the Prophet be. Tartarus proceeded down to the surface.

Departure
By the time Spartan-117 had reached the Prophet of Mercy, the Prophet was nearly dead and the marines he had rescued had similarly fallen. In his interrogation of the Prophet, he discovered that the Prophet of Truth was fleeing towards Earth. With the Arbiter still on Installation 05 and Cortana stating that she could detonate In Amber Clad's reactors if it was needed to destroy the Halo installation, the Spartan proceeded to follow the Prophet of Truth and attempt to board his ship before it left. However, Cortana chose that she couldn't trust the failsafe detonation of In Amber Clad to any copy of herself and had to remain behind.

While Cortana tried to stall the launch of the Forerunner ship, the Master Chief moved through the maze of High Charity, fighting Flood and Covenant alike to board the ship. In the end, he got on board with mere seconds to spare.

Covenant Civil War
The Battle became the starting point of the Covenant Civil War. Warships around High Charity continued to fight well after the battle was over. However, whether the battle's outcome would have any lasting impact on the outcome of the Covenant Civil War is currently unknown.

Tartarus and the Index
Tartarus would eventually make it to the Control Room with Miranda Keyes and begin the firing sequence for Installation 05. However, the Chieftain would eventually fall and the firing sequence canceled, putting all Installations into standby mode.

The battle would be the starting point for the alliance between the Covenant Seperatists and the UNSC.

Prophet of Truth and Spartan-117
The Prophet of Truth and Spartan-117 would eventually join the Second Battle of Earth aboard the Forerunner ship. Admiral Hood initially ordered the ship to be destroyed, but Spartan-117 identified that he was aboard the ship and wanted to finish the fight.

High Charity
The Flood eventually gained full control of High Charity and the Gravemind would take up residence in the fortress. However, the city was disabled with the decoupling of the Forerunner ship, without powered and likely unable to move. Cortana, stranded in High Charity's computer, would be questioned by the Gravemind.