Raid on the Threshold gas mine

"Be silent and swift, and we shall quell this heresy without incident."

- Rtas 'Vadumee

During the Ninth Age of Reclamation, the forces of the Covenant, under the command of Arbiter Thel 'Vadamee and Special Operations Commander Rtas 'Vadumee, launched a raid against the heretical movement led by Sesa 'Refumee on a Forerunner gas mine over the planet Threshold, near the ruins of Halo Installation 04. The strike force's objective was to assassinate 'Refumee, whom the Hierarchs saw as a threat and offense to the Covenant.

Background
During the Battle of Installation 04 in September 2552, the Prophet of Stewardship sent a team led by Third Commander Sesa 'Refumee and Loka 'Bandolee to the gas mine to recover Forerunner artifacts. When the ring was destroyed by Spartan John-117, this artifact retrieval team survived aboard the mine. Some time later, 343 Guilty Spark, the monitor of Installation 04, arrived at the gas mine. While initially met with hostility by Kig-Yar members of the team, a Sangheili intervened and brought the monitor to the commander. 'Refumee proclaimed that the Hierarchs would be pleased that an "Oracle" had survived the destruction of the Halo ring, but the monitor instead revealed that the Halo Array was not in fact a means for the Covenant's faithful to achieve paradise by means of the "Great Journey", but would instead kill all sentient life in the galaxy in order to starve the Flood. Upon hearing the monitor's words, 'Refumee had his forces cut off all communications with the remaining vessels of the Fleet of Particular Justice, as he wished to hear everything that Guilty Spark had to say.

'Refumee and Guilty Spark had a lengthy conversation over the history of the Covenant and the Sangheili, during which it was made clear to 'Refumee the extent of San'Shyuum's manipulation of the Sangheili in order to keep them blindly loyal and subservient, a fact readily apparent by their twisting of the ancient Sangheili title of Arbiter from a position of honor and power into a badge of shame for the Sangheili's most shamed warriors. 'Refumee initially considered conveying these revelations to his commander, Thel 'Vadamee, the only individual that he felt he could trust with 343 Guilty Spark's revelations. However, Thel's disgrace and appointment as Arbiter prevented any detailed conversations. 'Refumee subsequently led the Sangheili, Kig-Yar, and Unggoy under his command to revolt against the Prophets, declaring his intentions to spread the knowledge he had learned to others within the Covenant, making them aware of the lies and falsehoods told to them by the ruling Hierarchs, with the ultimate goal of inciting a full-scale rebellion within the Covenant. Aware that their proclamations would soon draw hostile attention once they reached the Covenant's leaders, the newly-formed separatist faction fortified their hold on the gas mine; Unggoy and Sangheili patrolled the facility's labyrinthine corridors, numerous Eeo'pimu-pattern Shades were deployed on the exterior surfaces of many of the mine's exterior structures and platforms, supplemented by units of fuel rod gun-wielding Unggoy, and squadrons of s patrolled the airspace surrounding the mine. Guilty Spark mobilized the facility's contingent of Aggressor Sentinels, bolstering the faction's defenses further.

By the following month, the Covenant's supreme leaders, the Hierarchs, became aware of the sect's existence. The Prophets of Truth and Mercy viewed these separatists as a threat to the Covenant and an offense to their religion, thus declaring them "heretics". Against the wishes of the High Council, Truth appointed Thel 'Vadamee, the disgraced former Supreme Commander of the Fleet of Particular Justice to the rank of Arbiter. The Hierarchs then sent 'Vadamee and a Special Operations team led by Special Operations Commander Rtas 'Vadumee to destroy the heretics.

Infiltration
The team departed High Charity on board three s, soaring past the remnants of Installation 04 towards Threshold. As they travelled, Commander 'Vadumee delivered a motivational speech to the troops under his command. As the Phantoms entered the gas giant's tempestuous atmosphere and closed with the large installation on which the gas mine was attached, 'Vadumee confronted the newly appointed Arbiter. His former commander, 'Vadumee now viewed Thel 'Vadamee with disdain following his failure to safeguard the Halo ring, and made it clear that while the lives of his troops mattered to him, the life of 'Vadamee did not. As the Phantoms closed with the gas mine, one of their pilots reported that the enormous maelstrom below the mine would undoubtedly strike the facility before long, to which 'Vadumee responded that the strike team will have long since accomplished their mission and departed by then. The Phantoms eventually arrived atop one of the many towers surrounding the main structure, and two of them deployed their complements of troops, including 'Vadamee. As the team made their way towards the nearest airlock, 'Vadumee encouraged the Arbiter to make use of stealth and speed in concert with the Special Operations unit to quickly eliminate the heretic forces, notifying the team that the nearby storm had masked their approach from the heretics, and thrown their local battle network into disarray, granting the team with the element of surprise. One of the teams Sangheili used a console to open the airlock, and the first lance made their way inside. The lance's commander ordered his troops to engage their active camouflage, telling them to only reveal themselves once the Arbiter initiated open combat with enemy forces. 'Vadumee told the Arbiter that he could also cloak himself, but had to use it sparingly as his armor's systems were of a more primitive design than those of modern Sangheili armor. Upon arriving at the first room inside the gas mine, the team found a group of sleeping heretic Unggoy and a pair of patrolling Sangheili. They overheard the Sangheili conversing about missing troops, as well as the presence of 343 Guilty Spark and his Sentinels. The team quickly took out the heretic soldiers and moved forward into a larger area with several energy belts ferrying Forerunner gas canisters into a deep pit. This larger room was occupied by more heretics and a battle soon erupted but the Covenant, with the support of a Shepsu-pattern plasma cannon, emerged victorious. The team pressed on, descending to a lower level below the conveyor room and eliminating several more heretics, including a group arriving from a nearby elevator. With the area clear, the Arbiter and his team boarded the elevator and descended towards a hangar bay containing a single. One of the Sangheili in the team observed the presence of Aggressor Sentinels in the room, noting with confusion their allegiance to the heretic forces. As the Arbiter and his team engaged in combat with the numerous heretic and Sentinel forces in the hangar, one of the strike team's Phantom pilots radioed 'Vadamee, requesting that they clear out the room and open the bay door so that he could enter and deploy the second lance to assist the team. The group fought their way across the room and the Arbiter opened the door. The Phantom entered and deployed reinforcements while the Arbiter assisted in repelling the attacks of both Sentinels and several fuel rod gun-wielding Unggoy. The heretics launched a final attack on the room, with groups of Unggoy and Sangheili entering from various doors around the room, including one leading deeper into the station. The heretics fought determinedly to stop the Covenant forces, with Unggoy setting up plasma cannons and an energy-sword wielding Sangheili but all of them fell to the Arbiter and his men. With the hangar clear, the team opted to follow the passageway deeper into the mine. They fought more heretics in close quarters, before emerging into another conveyor room where they encountered several heretic Sangheili wielding Sentinel beams. Overcoming all resistance in the room, the group found another door taking them even deeper. The group proceeded through the twisting corridors, silencing several patrolling and unaware heretic soldiers as they went. The Arbiter and his forces eventually reached a room with a large window looking out onto a landing pad with several parked s and heretics, including Sesa 'Refumee. the heretic leader ordered his soldiers to eliminate the Arbiter while he protected the "Oracle", before leaving in a Banshee. The strike team defeated the remaining heretics as well as several more Sentinels before pressing out to the landing pad. One of the team's Sangheili told 'Vadamee to continue his pursuit while they remained behind to secure the areas of the station they had passed through.

Commander 'Vadumee radioed the Arbiter, telling him that the heretic forces had mobilized their air forces, sending one of their Phantoms to support 'Vadamee in his hunt for the heretic leader. The Arbiter took to the skies in a Banshee, forming up with the Covenant Phantom before the two aircraft came under attack from numerous heretic Banshees. The Arbiter and his supporting Phantom destroyed their attackers in the vicinity of the landing pad. The Phantom's pilot informed 'Vadamee of the presence of heretic emplacements all over the exterior of the gas mine, telling him that they would take each one out until they located 'Refumee. The two ships proceeded to each position, encountering dozens of enemy Banshees, Shade turrets and fuel rod gun-wielding Unggoy. Eventually, the heretic leader was tracked to one of the large arms encircling the central module of the gas mine which was, unbeknownst to the strike team, one of the sections of the facility that had been retrofitted by 343 Guilty Spark into Flood research laboratories during the Forerunner's war against the Flood. The landing zone was heavily defended but the Arbiter successfully defeated all of the heretics in the area, allowing the Phantom to deploy another force of Special Operations troops, including Commander 'Vadumee.

Flood outbreak
As the group cautiously made their way into the next room, 'Vadumee paused and smelled the air, recognizing the stench of the Flood from his encounter with the parasite on board the Infinite Succor during the Battle of Installation 04. In the next room, the team passed a tank full of small creatures floating in liquid. In the next corridor they heard the sounds of combat as heretic forces were overwhelmed by Flood combat forms in the room below them. The roars and screams of the Flood forms unsettled the Unggoy in the team, but they soon quieted by one of the Sangheili. Noting that the victorious creatures had moved on, the group decided to press on in the hope of assassinating the heretic leader before the creatures could return. The team entered the next room and dropped to the bottom floor of a laboratory strewn with the corpses of Flood combat forms. The Unggoy in the team voiced their anxiety regarding the situation before a Sangheili warned them to be quiet. A holo-drone floated into the room, projecting an image of Sesa 'Refumee to the team. The Unggoy panicked and opened fire on the hologram before being ordered to stop by 'Vadumee. The heretic leader taunted the team through the projection, noting the decision of the Hierarchs to send an Arbiter to silence him. 'Vadumee realized that due to his use of the holo-drone, the heretic would likely be close by, and attempted to goad 'Refumee to face them, to which he laughed and told the Covenant forces to "get in line" before the holographic projection dissipated. A moment later, Flood Pod infectors began to pour into the room. Commander 'Vadumee shouted a warning to his soldiers as the small parasitic creatures assailed the group. After several waves of attacking Flood forms, the assault subsided and a nearby door opened, granting passage out of the laboratory. 'Vadumee told the Arbiter to continue onwards while he waited behind for additional Covenant reinforcements to arrive. The Arbiter and the surviving members of the Special Operations team made their way through another passageway that brought them to a massive circular elevator platform, upon which a pitched battle was underway between Flood combat forms and Sentinels. The team eliminated all hostiles in the area and moved onto the platform, which then began a slow descent towards the lower level of the facility, periodically stopping and rotating while its automated mechanical arm retrieved canisters containing Pod infectors from the walls of the chamber and loaded them on the platform. All the while, the team was forced to endure assaults from Flood combat forms climbing up the walls and leaping onto the platform as well as Sentinels. Eventually, the platform arrived at its destination and the Arbiter disembarked along with his remaining forces. The next corridor was littered with both heretic and Flood corpses, to which one of the Sangheili accompanying 'Vadamee stated that they should have brought along weaponry suitable for destroying the bodies to deny the Flood more biomass. The team eventually arrived on the upper level of a larger laboratory room, where a group of heretics were desperately fighting back against Pod infectors, combat forms and carrier forms. After clearing out the hostiles in the room, the Arbiter and his forces dropped down to the lower level, after which they were ambushed by a group of heretic Sangheili arriving from above. Before long, masses of Flood combat forms entered the room from vents high up on the walls and a vicious firefight soon developed. After several minutes of continuous attacks from the Flood, an airlock nearby opened up and a team of heretic forces arrived. After clearing out the opposition, the Arbiter and his warriors left through the door the heretics entered from. It was then that the Phantom pilot radioed in, reporting that the massive storm was about to strike the gas mine, and it was no longer safe for the Phantom to remain in the facility's airspace, to which Commander 'Vadumee told him to bring them in closer, stating that they would not leave until 'Refumee was dead. The airlock door opened revealing a battle underway between heretic and Flood forces on the walkway to the central facility of the gas mine. The Covenant Phantom then arrived, providing supporting fire while depositing extra forces to assist the Arbiter in his push into the heart of the mine. 'Vadumee reported that the Flood had infested the entire facility and that the Covenant had not the time or the forces necessary to manage the outbreak, telling the Arbiter that the heretic leader needed to be slain imminently. The group began to take one of the paths winding up and into the structure, battling waiting heretics and Sentinels as they went. Once inside, they spotted 'Refumee making a run for a door on the opposite side of the room. The heretic immediately sealed the doorway behind him with an energy field while Sentinels and combat forms did battle in the center. After all enemies were dealt with, 'Vadamee approached the sealed door where 'Refumee waited. The heretic taunted the Arbiter, telling him that he would be protected from the ensuing storm while 'Vadamee and his troops would be consumed before the doors sealed. 'Vadumee and his men arrived, the Commander asking the Arbiter where the heretic was. Upon noticing the energy field, 'Vadumee noted with frustration that they could not hope to break through by conventional means. The Arbiter, who had turned to study a nearby schematic of the gas mine, decided that he would cut the cable anchoring the gas mine to its parent installation, sending the mine plummeting into freefall to be crushed by Threshold's inner atmosphere and ensuring the death of Sesa 'Refumee and his surviving followers even at the cost of himself. 'Vadumee ordered all of his forces to return to the Phantom while the Arbiter cut the cable. 'Vadumee noted that the cable would likely be susceptible to damage from an energy sword before leaving the station himself.

Cutting the cable
The Arbiter ascended up a series of winding ramps, fighting Flood forms until he reached an elevator platform guarded by Sentinels. After dealing with them, 'Vadamee took the elevator up to the room in which the cable was anchored to the station. 'Vadumee reported that all of the strike force's Phantoms had left the facility, allowing the Arbiter to cut the cable. The Arbiter made his way around the room battling Flood and Sentinels as he located three points where the cable was anchored. After using his energy sword to sever these points, the Arbiter quickly returned to the elevator platform as the station violently tore away from the cable, plummeting into freefall. Upon returning to the station, the Arbiter made his way back to the door that had previously been sealed, fighting Flood and surviving heretics as he went. A group of heretic soldiers waited inside the formerly-shielded room that 'Refumee had since vacated, one of them yelling to his men to give their lives for the truths that the heretics had realized about the Covenant. The Arbiter soon slew 'Refumee's rearguard and took an elevator down, making his way through a chamber with a massive generator in the center and fighting past several more heretics as he went, including an energy sword-wielding Sangheili. The Arbiter soon found himself in close pursuit of the heretic leader, and the two traded shots even as 'Refumee ran for a Banshee on the nearby landing pad. The heretic made it to the Banshee as Thel arrived, the latter firing several shots from his Vostu-pattern carbine at the Banshee. Unfortunately, these shots were absorbed by the Banshee's energy shield and he was forced to roll into cover behind another parked Banshee as 'Refumee opened fire with his Banshee's plasma cannons. 'Refumee then flew away, making for the hangar bay where his single Seraph fighter was parked. The Arbiter was quick to pursue, taking control of the remaining Banshee on the platform and racing after the heretic leader while dodging pieces of the station that were breaking off as it continued to fall into the raging maelstrom. Initially believing the heretic to be making an impossible escape from the station in a Banshee, 'Vadumee remembered the presence of the Seraph in the hangar and urged the Arbiter to make his way back after the heretic. 'Vadamee attempted to land his Banshee on the platform leading into the station but the roaring winds caused him to instead crash violently into it. Unharmed, the Sangheili pulled himself up and hastily made his way through the door and back inside. Once back in the station, the Arbiter was forced to backtrack the path he had taken during his initial push through the mine. On the way, he was accosted by Flood forms as well as Sentinels as he raced through the darkened corridors which were now only illuminated by red emergency lighting. As he passed through a conveyor room in which all of the energy belts were now inactive, he encountered several surviving heretics who were attempting to flee back to the hangar to cover their leader. After cutting through these forces and making his way through corridors filled with Flood forms, he found a final heretic strongpoint in the final room before the hangar. Here, the heretics mustered their remaining forces; numerous Sangheili and Unggoy took cover behind stationery shield generators and fought furiously against encroaching Flood forms as well as the Arbiter in order to buy 'Refumee time to escape. 'Vadamee eventually broke through these defenses and made his way into the hangar bay.

Final confrontation
The Arbiter entered the room just as Sesa 'Refumee was about to board the Seraph. Raising his Carbine, 'Vadamee demanded his enemy to turn and face him. The heretic leader jumped down from the fighter, telling 'Vadamee that he would rather die by the Arbiter's hand rather than die blinded by falsehoods conveyed by the Prophets. 'Vadamee demanded to know who had taught the heretic the lies that he preached, to which 343 Guilty Spark revealed himself to the surprise of the Arbiter. While 'Refumee told the Arbiter to ask the Oracle about Halo and its true purpose, the heretic used the Arbiter's surprise to draw his dual s and opened fire on 'Vadamee, who was forced to fall back into cover behind a nearby pillar. 'Refumee used his antigravity pack to return to the Seraph. Declaring that the Sangheili species was blinded to the Prophet's lies and his intention to make them see the truth, the heretic activated a pair of holo-drones which floated into position in front of the Arbiter, each one equipped with their own pair of plasma rifles. As the Arbiter fought against the heretic leader and his holographic decoys, 'Refumee continued to taunt the Covenant soldier, mockingly asking how the Hierarchs had secured his loyalty, as well as the supposed "transcendence" of the Forerunners and the Covenant's "Great Journey". Guilty Spark also spoke to the Arbiter during the battle, notifying him of his personal involvement in the gas mines retrofitting as a Flood research facility, as well as the detachment of the gas mine as a failsafe to be used in the event of the parasite's escape. After a protracted battle, the Arbiter was successful in slaying Sesa 'Refumee. As 'Vadamee dragged the heretic's corpse to the opening hangar door, Guilty Spark expressed remorse for the killing of 'Refumee, to which the Arbiter replied that it was his only choice due to the threat the heretic posed to the Covenant and its beliefs. The monitor expressed bemusement at the phrases of "Oracle" and "Great Journey", stating them to be wildly inaccurate, before he was suddenly captured in a gravitational force projected by Tartarus' gravity hammer, the Fist of Rukt. The monitor was sent hurtling towards the Jiralhanae's hammer. As Tartarus pulled Guilty Spark off the head of his hammer and casually threw him into the gravity lift of the waiting Phantom, 'Vadamee expressed outrage in the Chieftain's handling of the monitor, to which Tartarus merely told him to board the Phantom as they were leaving the Soell system.

Aftermath
Following the death of Sesa 'Refumee and all of his followers on the gas mine, the rebellion was successfully quelled. Additionally, all of the escaped Flood on the gas mine were killed once the station fell deeper into Threshold's atmosphere and was destroyed. Despite the death of 'Refumee, his words had planted a seed of doubt into 'Vadamee's mind. After the Arbiter was presented the same message by the Gravemind, John-117, and 343 Guilty Spark during the events at Installation 05 in the following month, he slowly came to believe 'Refumee's words. Ultimately, the ideals that Sesa 'Refumee's faction promoted were later revived during the Great Schism by the Covenant separatists. In the years following the war, Arbiter Thel 'Vadamee sought to recognize 'Refumee's efforts in changing the course of their species for the better, granting special dispensation to the members of 'Refum keep in the Swords of Sanghelios.

Following his capture by the Covenant, 343 Guilty Spark was brought to High Charity and was on the city when it arrived at Installation 05 on November 2, 2552. The Prophets of Truth and Mercy questioned the monitor about the ring, learning of the installation's Activation Index. They would later dispatch Arbiter Thel 'Vadamee to retrieve this "Sacred Icon".

List of appearances

 * Halo 2
 * Halo 2: Anniversary
 * Halo Mythos: A Guide to the Story of Halo