Assassination of the Prophet of Regret

The Assassination of the Prophet of Regret was an operation carried out by UNSC forces from the  to assassinate the Covenant High Prophet of Regret on November 2, 2552, after following the Prophet's assault carrier Solemn Penance from Earth to Installation 05.

Background
Following his discovery of the location of the portal leading to the Ark, a facility that would allow the Covenant to fulfill their "Great Journey", the High Prophet of Regret took a hastily-assembled fleet of fifteen vessels to the planet, unaware that it was the homeworld of humanity. The fleet arrived on October 20, 2552 and was immediately engaged by the vastly numerically-superior UNSC Home Fleet. As the Fleet of Sacred Consecration fought a losing battle over the planet, Regret took his flagship, the Solemn Penance directly down to the city of New Mombasa in eastern Africa. The Prophet deployed ground troops into the city to search for the location of the Ark's portal. Eventually, as human ground forces closed in on his carrier's landing zone and UNSC vessels prepared to deploy forces onto the carrier from above, Regret initiated a slipspace jump while still over the city, using information he had learned from the Luminary recovered from Meridian to plot a course for Installation 05.

Despite being caught off-guard by the Prophet's sudden departure, the UNSC, captained by Commander Miranda Keyes was close enough to pursue the assault carrier. After being given permission from Fleet Admiral Hood, the In Amber Clad, with Spartan John-117 and Sergeant Major Avery Johnson onboard, followed the departing Covenant carrier as it transitioned into slipspace near the city's space elevator. Several UNSC vessels followed the pair into slipspace using the assault carrier's wake, but became separated from the Solemn Penance and In Amber Clad.

The battle
"Avery Johnson"

- Cortana

The Solemn Penance exited slipspace on November 2, 2552, arriving in close proximity to Installation 05, orbiting the gas giant Substance in the Coelest system. The Prophet of Regret took Solemn Penance down to the surface of the ring, deploying large numbers of ground troops and armor into a network of Forerunner ruins. The Hierarch fortified himself within a temple in the middle of a large lake and began to sermonize to his loyal forces, declaring his intent to activate the installation and begin the Covenant's "Great Journey".

Meanwhile, Commander Miranda Keyes of the, trailing behind the assault carrier, opted to keep a low profile to avoid detection by the far more powerful. She realized the importance of discovering why the Covenant had attacked Earth as well as their arrival at the Halo ring and designated the capture or killing of the Prophet of Regret as their primary objective. She ordered John-117 and a platoon of Orbital Drop Shock Troopers from the 7th Shock Troops Battalion to deploy via M8823 SOEIV to secure a landing zone to Sergeant Major Avery Johnson to deploy more ground forces to support them. As the In Amber Clad made a pass over the ring, the frigate deployed a dozen SOEIV pods. While most survived to enter the atmosphere, Covenant ground forces had deployed a number of Shade turrets in the landing zone that opened fire on the pods as they neared the surface. Several pods were struck and destroyed and many ODSTs were immediately killed by Covenant troops upon leaving their pods. Ultimately only four UNSC personnel would survive to make landfall-John-117 and three ODSTs. Wielding a rocket launcher, the Spartan destroyed the Shade turrets and led the surviving ODSTs into a nearby Forerunner structure. The four secured the ruins and managed to hold off several Phantoms and their complements of infantry, allowing Sergeant Johnson to approach in a Pelican to deploy a Warthog for the team. As the Pelican approached the landing zone, Johnson spotted the structure in the lake that the Prophet of Regret had taken refuge in and notified the team of its location. John-117 and his team commandeered the Warthog and set out toward their objective, wiping out a camp of Kig-Yar snipers before arriving in a large area fortified by the Covenant, who retracted the bridge spanning a nearby gorge. The UNSC forces eventually cleared the area out and extended the bridge. The presence of s across the gorge necessitated the deployment of a Scorpion tank, which Johnson's Pelican deployed for the Spartan. John used the tank to destroy the Wraiths before pushing through a network of Forerunner ruins, destroying various Covenant positions until they finally emerged into an open area with another large structure. A Pelican arrived to drop off several ordnance pods and more Marines to support the offensive. John and the Marines fought through several more structures and caves, battling through more Covenant before reaching the first lake structure, encountering members of the Covenant Honor Guard within. As the Master Chief made to leave the structure, Cortana called for him to stop near a holographic projection of the Prophet of Regret. She confirmed that Regret was planning to activate the installation to John, translating the sermon into English. John radioed Commander Keyes about the situation. Keyes, after studying the information Cortana had acquired from Installation 04, knew that the Prophet would need the ring's Index to activate the installation. Having located the Library where the Index would be housed, and determined to deny it from falling to the Covenant, Keyes ordered Johnson to extract his men and rendezvous with her at the Library. Now armed with all the intel they needed, Keyes ordered John to assassinate the Covenant Hierarch. Before John could leave the structure, he was attacked by a swarm of Yanme'e. Pressing onward, he fought his way around the exterior of the structure, finally arriving in a circular arena. After clearing out the Covenant in the area, a Phantom deployed a Mgalekgolo pair to stop the strike team but John was able to eliminate them, allowing a Pelican to arrive with more ordnance pods and reinforcements. An goldola packed with Covenant troops arrived but the UNSC forces managed to take them out and boarded the gondola, riding it out to another structure on the lake. Upon arrival, they quickly cleared out the Covenant occupiers and boarded an elevator car that took them to the next structure while Cortana intercepted a transmission on the proselytization network from Regret's assault carrier to the Prophets of Truth and Mercy in High Charity. The Prophet of Regret expressed his forgiveness for his rash attack on Earth, arguing that he was unaware of the human presence on the planet, something Cortana considered odd-in reality a fact purposely withheld by the Prophet of Truth from his fellow Hierarchs. Upon arrival at the next structure, the pressed forward through several submerged corridors and a large chamber, eliminating huge numbers of Covenant troops including snipers, Mgalekgolo and more Sangheili Honor Guardsmen. They eventually reached another elevator car as Cortana intercepted the Prophet of Truth's response to Regret, chastising the younger Hierarch for his actions and telling him that he had only avoided public condemnation due to the Prophet of Mercy's counsel. The team continued to fight their way outside, where the Pelican returned to provide a final supply run for the Spartan. Rearmed and reinforced, John pushed into another set of ruins occupied by Covenant forces, fighting his way to the gondola that would take him to the Prophet of Regret's temple. Cortana reported to Commander Keyes that they had almost reached their objective. The gondola arrived at the temple, and John and his team quickly killed the troops guarding the exterior but as they left the gondola, High Charity and it's massive defense fleet exited slipspace high above the installation. Cortana stated that this was the largest Covenant fleet ever seen by humanity, urging the Spartan to finish off Regret before they could intervene.

The Spartan fought his way into the structure as Cortana warned him that the fleet had launched waves of Phantoms towards the temple. With his time running out, John emerged into the temple's main chamber, where the Prophet of Regret himself waited, surrounded by his Honor Guard. Quickly realizing that the Prophet's gravity throne projected an energy shield too powerful to attack with conventional weaponry, the Spartan opted to physically board Regret's throne and beat the frail Prophet to death, while the remaining Marines engaged the Honor Guards. As the lifeless Prophet of Regret tumbled to the floor and his throne exploded, Cortana warned John that the Phantoms had been withdrawn and the fleet was preparing to fire on the temple. John sprinted out of the temple and began to run as Shipmaster Rhul 'Salmutee had the Solemn Penance target the temple with the assault carrier's energy projector in an attempt to kill the Spartan. John barely managed to escape, leaping into the lake as the temple was completely destroyed. As he drifted through the water, a large tentacle belonging to the Flood Gravemind ensnared the unconscious Spartan, and took him captive. The remaining Marines were either killed in combat or by the blast from the carrier's energy projector.

Aftermath
The death of Regret allowed the Prophet of Truth to consolidate his grip on the Covenant. Using the death of the Hierarch as an excuse to discredit the Sangheili, Truth ordered a restructuring of the Covenant Honor Guard, casting the Sangheili out and replacing them with the Jiralhanae. While eavesdropping on a meeting between the Prophet of Truth, the Prophet of Exquisite Devotion and the Chieftain of the Jiralhanae Tartarus, Zo Resken, Truth's Second Administrator, overheard the three as they discussed their plans to elevate the Jiralhanae above the Sangheili, and later received news from G'torik 'Klemmee revealing that Truth had deliberately withdrawn the Phantoms sent down to reinforce the Prophet of Regret to ensure his death at the hands of the Master Chief. This was but one part of a "divisive mandate" that Truth had set in motion years prior. Secretly, he had devised a complex scheme, one which would soon culminate in the Great Schism, with the Sangheili being forced out of the Covenant. This would ultimately result in the deaths of the remaining Hierarchs, and the complete fragmentation of the Covenant during the Battle of Installation 00 a month later.

John-117 would be brought into the Gravemind's lair deep below Installation 05's Library, where he would come face-to-face with Thel 'Vadamee, Arbiter of the Covenant and the former Supreme Commander of the Fleet of Particular Justice, as well as the installation's monitor, 2401 Penitent Tangent and the reanimated corpse of the Prophet of Regret. The Gravemind brought the four together in order to explain the truth behind the Halo Array's function to 'Vadamee. When both John and the Gravemind's words failed to sway the Arbiter, the Gravemind opted to show the Sangheili for himself. Instructing the Chief and Arbiter to seek out the Activation Index, the Gravemind manipulated the ring's teleportation grid to teleport John-117 into High Charity while Thel 'Vadamee was sent to the cliffs near the installation's control room.

List of appearances

 * Halo 2
 * Halo: Broken Circle
 * Halo 2: Anniversary
 * Halo Mythos
 * Halo: Official Spartan Field Manual