Editing Battle of Installation 05

{{Era|HCW}}
{{Battle Infobox
|prev=[[Raid on the Threshold gas mine]]
|conc=[[Battle of High Charity|Battle of ''High Charity'']], [[Battle of Earth]], [[Battle of Onyx]]
|next=[[Battle of Mare Erythraeum]]
|name=Battle of Installation 05
|image=[[File:H2A - Battle of Delta Halo.jpg|300px]]
|conflict=[[Human-Covenant War]], [[Great Schism]]
|date=[[2552#November|November 2, 2552]] – [[2552#November|November 4, 2552]]
|place=[[Installation 05]], [[Coelest system]]
|result=;Strategic UNSC/Sangheili victory
*Tartarus, and the Prophets of Regret and Mercy are killed
*[[Great Schism|Fracturing]] of the Covenant as Truth becomes the Covenant's sole dictator
*Thel 'Vadam's faction forms an alliance with the UNSC
*[[Halo Array]] enters standby mode 
*Flood on the installation are sterilized by Sangheili
;Tactical Flood victory
*Flood successfully escape Installation 05 
*''High Charity'' assimilated by the Flood
|side1=[[United Nations Space Command]] <br> [[Swords of Sanghelios|Sangheili]] <br> [[Forerunner]] constructs
|side2=[[Covenant]]
|side3=[[Flood]]
|commanders1=[[Miranda Keyes|CMDR Miranda Keyes]] <br>
[[John-117|MCPO John-117]] <br>
[[Avery Johnson|SgtMaj Avery Johnson]] <br>
[[Arbiter]] [[Thel 'Vadam]] <br>
[[Special Operations Commander]] [[Rtas 'Vadum]] <br>
[[Shipmaster]] [[Tano 'Inanraree]]† <br>
[[343 Guilty Spark]]<br>
[[Sangheili Field Commander|Commander]] [[G'Torik Klemmee]]
|commanders2=[[Prophet of Truth]] <br>
[[Prophet of Mercy]]† <br>
[[Prophet of Regret]]† <br>
[[Chieftain of the Jiralhanae|Chieftain]] [[Tartarus]]† <br>
Arbiter [[Thel 'Vadam]] {{C|defected}} <br>
Special Operations Commander [[Rtas 'Vadum]] {{C|defected}} <br>
[[Shipmaster]] [[Gargantum]]<br>
[[Jiralhanae Captain|Captain]] [[Melchus]]
|commanders3=[[Gravemind]]
|forces1=
*[[UNSC Navy]]
**{{UNSCShip|In Amber Clad}}
***[[M808B Scorpion]]s
***[[M12 Warthog LRV]]s
***[[D77-TC Pelican]]s
**[[John-117]]
*[[UNSC Marine Corps]]
**[[Orbital Drop Shock Troopers|ODSTs]] <br>
Sangheili-allied forces
*{{Class|Reverence|cruiser}}s
*{{Class|DDS|carrier}}s
*{{Class|CCS|battlecruiser}}s
*[[Covenant destroyer|Destroyers]]
*[[Sangheili]]
*[[Mgalekgolo]]
*[[Unggoy]]
*[[Type-47 Scarab]]
*[[Type-26 Wraith]]s
*[[Type-46 Spectre]]s
*[[Type-26 Banshee]]s
*[[Type-32 Ghost]]s <br>
Forerunner constructs
*[[Aggressor Sentinel]]s and [[Enforcer]]s
|forces2=
Covenant forces
*''[[High Charity]]''
*[[Second Fleet of Homogeneous Clarity]]
**[[Covenant assault carrier|Assault carriers]]
**[[Covenant frigate|Frigates]]
*{{Class|CCS|battlecruiser}}s
*[[Covenant destroyer|Destroyers]]
**[[Jiralhanae]]
**[[Kig-Yar]]
**[[Yanme'e]]
**Sangheili {{C|until Schism}}
**Mgalekgolo
**Unggoy
*Wraiths
*Spectres
*Banshees
*Scarab
*Ghosts
|forces3=*[[Flood]] forms
**[[Flood infection form|Infection forms]]
**[[Flood combat form|Combat forms]]
**[[Flood carrier form|Carrier forms]]
**1 [[Gravemind]]
|casual1=*''In Amber Clad''
*Many infantry and vehicular loses
*Large numbers of assorted starships
*Large numbers of Sentinels and Enforcers
*Sentinel construction factory
|casual2=*''[[High Charity]]'' captured
*Prophets of Regret and Mercy
*Tartarus
*Many infantry and vehicular loses
*Large numbers of assorted starships
|casual3=Large numbers of assorted Flood forms
}}
{{Quote|no=two|1=Miranda Keyes|q1=Cortana, what exactly am I looking at?|2=Cortana|q2=That... is another Halo.|3=[[Miranda Keyes|Commander Miranda Keyes]] and [[Cortana]] upon discovering the installation<ref name="deltahalo">'''[[Halo 2]]''', campaign level ''[[Delta Halo (level)|Delta Halo]]''</ref>}}

The '''Battle of Installation 05''', also known as the '''Battle for the Second Ring of the Gods''' among the [[Covenant]],<ref>'''[[Halo: Ghosts of Onyx]]''', ''page 241''</ref> was a major engagement in early [[2552#November|November 2552]] between the Covenant, the [[Flood]], and the [[United Nations Space Command]], with the aid of [[Forerunner]] [[Sentinel]]s and [[Swords of Sanghelios|those loyal to]] [[Thel 'Vadam|the Arbiter]] on the Forerunner [[Halo Array|ringworld]] [[Installation 05]], otherwise known as "Delta Halo".

The battle saw the [[Covenant remnants|splintering]] of the Covenant empire as the [[Great Schism]] began, and the formation of an alliance between [[human]]ity and the [[Sangheili]].

==Prelude==
In [[97,227 BCE]], [[343 Guilty Spark]]—[[monitor]] of [[Installation 04]]—warned the monitor of [[Installation 05]]—[[2401 Penitent Tangent]]—of a pending outbreak in one the installation's [[Flood containment facility|Flood containment facilities]]. However, Penitent Tangent ignored the warning, and those that followed, for millennia. The installation's [[sentinel]]s managed to keep the [[Flood]] largely contained in the [[Quarantine Zone]] around the [[Library]], although the machines never managed to fully destroy the infestation.<ref>'''[[Halo 3]]''', multiplayer map ''[[Cold Storage]] [[Installation 05 containment failure report|transmissions]]''</ref> Eventually, a [[Gravemind]] formed on the installation and captured Penitent Tangent.<ref name="gravemind">'''Halo 2''', campaign level ''[[Gravemind (level)|Gravemind]]''</ref>

[[File:H2A - In Amber Clad approaches Halo.png|thumb|250px|left|''In Amber Clad'' approaches Installation 05.]]
At the beginning of the [[Battle of Earth]] in [[2552#October|October 20, 2552]], the [[Prophet of Regret]] led [[Fleet of Sacred Consecration]], which contained two {{Class|CAS|assault carrier}}s and thirteen {{Class|CCS|battlecruiser}}s on an expeditionary raid that stumbled upon [[Earth]], [[human]]ity's homeworld and the UNSC's strongest fortress.<ref name="cairo">'''Halo 2''', campaign level ''[[Cairo Station (level)|Cairo Station]]''</ref> After substantial ground, air, and space losses, and faced with the possibility of being overrun on the ground and intercepted by UNSC ships if it tried to escape to orbit, Regret ordered a retreat. With Regret aboard, ''[[Solemn Penance]]'' made an emergency in-atmosphere [[slipspace]] jump over [[New Mombasa]], with the {{Class|Stalwart|light frigate}} {{UNSCShip|In Amber Clad}} following it into slipspace.<ref name="deltahalo"/><ref name="metro">'''Halo 2''', campaign level ''[[Metropolis]]''</ref>

At [[Terrence Hood|Fleet Admiral Lord Terrence Hood]]'s order, {{UNSCShip|Coral Sea}}, {{UNSCShip|Dusk}}, {{UNSCShip|Paris}}, and {{UNSCShip|Redoubtable}} were sent to follow and assist the ''In Amber Clad'' with the heavy assault carrier, as they were the closet, fastest UNSC ships to the carrier with charged slipspace capacitors. The ships intended to find out where the assault carrier was heading, or destroy the ship entirely to kill Regret.<ref>'''Halo: Ghosts of Onyx''', ''pages 185-186''</ref> Their shadowing, however, was not exactingly precise. Only the frigate ''In Amber Clad'' successfully trailed the assault carrier to its destination. ''Dusk'', a [[prowler]], arrived a day later near the Covenant holy city of ''[[High Charity]]''. What became of the ''Coral Sea'', ''Paris'', and ''Redoubtable'' is unknown.<ref name="goo189">'''Halo: Ghosts of Onyx''', ''page 189''</ref>

==The battle==
===Opening actions===
On [[2552#November|November 2, 2552]], ''Solemn Penance'' exited slipspace over [[Installation 05]], orbiting [[Substance]] in the [[Coelest system]]. Regret's assault carrier took position over the installation, establishing a solid ground presence with armor and patrols of [[Type-26 Banshee]]s, and also companies of infantry by means of [[Type-52 Phantom]]s. The Covenant ground forces fortified themselves in a series of Forerunner ruins and temple structures, establishing [[Shade|anti-air defenses]].<ref name="deltahalo"/>

[[File:H2A - HEVs over Delta Halo.jpg|thumb|250px|left|John-117 and five ODSTs insert into the atmosphere of Installation 05 in HEVs.]]
Meanwhile, ''In Amber Clad'' trailed behind and [[Miranda Keyes|Commander Miranda Keyes]], captain of ''In Amber Clad'', ordered a [[platoon]] of [[Orbital Drop Shock Trooper]]s and [[John-117]] to establish a [[landing zone]] near a series of ruins and temples on Installation 05 to allow [[Avery Johnson|Sergeant Major Avery Johnson]] to bring in two [[D77-TC Pelican]]s to further expand the UNSC presence. The frigate made a quick pass-over of a segment of the ringworld, deploying a dozen [[Single Occupant Exoatmospheric Insertion Vehicle|SOEIV pods]]. Six survived the atmosphere of the ring, and only four personnel eventually survived the impact—John-117 and three ODSTs. However, before they could land in the ruins, they were detected by the Covenant. Upon landing, SPARTAN-117 led the ODSTs in eliminating Covenant Shades and holding their position against waves of Covenant troops until a Pelican could drop off a [[M12 Warthog LRV]] and a pair of [[UNSC Marine Corps|Marines]]. Although a major objective for John-117 and the Marines was to capture or assassinate the Prophet of Regret, the most important UNSC objective was to prevent the Covenant from activating the installation to fulfil [[Covenant religion|their religion]]. To do this, UNSC forces had to infiltrate the [[Library]], retrieve the [[activation index]] to prevent the Covenant from using it to activate Installation 05.<ref name="deltahalo"/>

After [[Cortana]] translated a sermon from the Prophet of Regret, the UNSC became aware that the Covenant was intending to activate Installation 05. Regret's elimination became the primary objective for John-117, as his death would destabilize the Covenant politically and religiously. John-117 and a pair of Marines battled through a pair of Covenant-held temples before reaching an open platform. At the time, the Covenant became aware of UNSC activity and became increasingly aggressive, so Commander Keyes sent several Pelicans towards John-117, which air-dropped more resupply canisters on the platform. The UNSC continued their attack, proceeding from the platform to an [[anti-gravity gondola]] which took John-117 and his remaining Marines to a heavily-defended Forerunner underwater temple with a heavy Covenant presence. After emerging from the submerged temple at a hilly Forerunner ruin, they were engaged by more Covenant infantry reinforced by Phantoms attempting to halt the UNSC advance.<ref name="regret">'''Halo 2''', campaign level ''[[Regret (level)|Regret]]''</ref>

===Assassination of Regret===
[[File:MC attacks Regret.jpg|thumb|250px|John-117 kills the Prophet of Regret.]] 
However, the Covenant were ultimately unsuccessful. The UNSC succeeded in clearing a landing zone and more Marines were deployed to assist John-117 in reaching [[Temple (Installation 05)|the temple]] the Prophet of Regret was located in. The UNSC forces commandeered an anti-gravity gondola, and despite being attacked by Covenant [[Type-26 Banshee]]s and [[Sangheili Ranger]]s, they were able to gain access to the main temple. After destroying several defense turrets, they entered the temple as the Prophet of Regret was finishing his sermon. Regret transmitted an apology to the [[Prophet of Truth]], asking for forgiveness for his rash actions at [[Earth]] and for aid at the new installation. Truth, with the [[Prophet of Mercy]]'s advice, reluctantly sent a large portion of the [[Covenant fleet]] to Installation 05 to retrieve the [[Hierarchs|Hierarch]]. Shortly after, ''[[High Charity]]'' reverted from slipspace over Installation 05, along with the hundreds of warships of the [[High Charity defense fleet|''High Charity'' defense fleet]] and the [[Second Fleet of Homogeneous Clarity]]. Responding to a distress signal from Regret, [[Special Operations Commander]] [[Rtas 'Vadum]]ee planned to storm the temple by Phantom [[dropship]]s in an urgent measure to kill John-117 and defend the Hierarch. However, the treacherous Prophet of Truth ultimately diverted the Phantoms, deliberately allowing the [[SPARTAN-II program|SPARTAN-II]] to kill Regret as part of his socio-political plans for the Covenant.<ref name="regret"/>

A large contingent of [[Sangheili Honor Guardsman|Sangheili Honor Guardsmen]] and [[Unggoy]] defended the Prophet, but John-117 was able to board the Prophet's [[anti-gravity chair|gravity throne]] and beat the Prophet to death. During the fray, all the remaining Marines were presumably killed. Shortly thereafter, ''Solemn Penance'' repositioned over the main temple, and destroyed it with its [[energy projector]]. John-117 fell into the lake with seconds to spare and was grasped by the tentacles of the [[Gravemind]], a [[Flood]] compound intelligence, and taken prisoner.<ref name="regret"/>

===The containment shield===
[[File:H2 Containment Shield.jpg|thumb|250px|left|Tartarus's Phantom nears the containment shield to deploy the Arbiter.]]
The Hierarchs' confidence in the abilities of the Sangheili Honor Guardsmen declined when the Prophet of Regret's bodyguards failed to save him from death at the hands of John-117. As a result, the High Prophets of Truth and Mercy ordered the Sangheili to step down as the protectors of the Prophets. In their place, the [[Jiralhanae]] [[Changing of the Guard|filled in the void]] left by the disgraced Sangheili. Soon, the UNSC and the Covenant both raced to reach Installation 05's [[Library]] and seize the [[activation index]]. The UNSC wanted to keep it safe to prevent the activation of the installation, but the Covenant desired to bring the "Sacred Icon"—the Covenant name of the index—to the [[Control Room (Installation 05)|Control Room]] of the ring and activate the ring.<ref name="icon">'''Halo 2''', campaign level ''[[Sacred Icon]]''</ref>

Before either faction could reach the Library, it was shielded by the [[containment shield]]—a recognized impenetrable [[energy shielding|energy shield]] denying anyone access to the Library. The shield was projected by a Forerunner power generator buried within a [[Sentinel wall]], a large Forerunner complex heavily defended by various types of [[Sentinel]]s, including [[Aggressor Sentinel|Aggressors]] and [[Enforcer]]s. Numbers of Jiralhanae, [[Kig-Yar]], and Unggoy had attempted to penetrate the Sentinel wall, but they were all overwhelmed by Sentinel defenders. However, [[Arbiter]] [[Thel 'Vadam]]ee was air-dropped by [[Chieftain of the Jiralhanae]] [[Tartarus]]'s Phantom at the periphery of the wall in the beginning phase of a Covenant offensive to deactivate the containment shield, enter the Library, and seize the Sacred Icon. Eventually, the Arbiter battled his way through the area and deactivated the shield. However, there was a rampant Flood infestation: the second half of the Sentinel wall became heavily saturated with Flood forms, and the Flood soon began to outnumber the Sentinel defenders. Tartarus attempted to pick up the Arbiter in his Phantom and head directly for the Library, but his dropship was engaged by an Enforcer, forcing the Arbiter to battle through through the warring Flood and Sentinels that resided in the Flood-infested wall by himself.<ref name="icon"/><ref name="guide115">'''[[Halo 2: The Official Strategy Guide|The Official Halo 2 Strategy Guide]]''', ''page 115''</ref>

However, the Arbiter was not alone—the UNSC had dispatched a squad of Marines to also fight through the facility, but they were overwhelmed by the Flood, leaving a trail of crumpled bodies throughout the facility and fueling the Flood's ever-growing army. The Covenant apparently sent a small team of three [[Special Operations Sangheili]] to clear out the lower levels of the complex, but these too were killed. Finally, the Arbiter managed to exit from the Sentinel wall and enter the battle-torn icy plains of the [[Quarantine Zone]].<ref name="icon"/>

===Battle of the Quarantine Zone===
{{Main|Battle of the Quarantine Zone}}
[[File:Sacredicon1600.jpg|thumb|250px|The Library of Installation 05 situated deep inside the Quarantine Zone.]]
{{Quote|We shall cut into the heart of [[Flood|this infestation]], retrieve the icon, and burn any Flood that stand in our way! Forward, warriors, and fear not pain or death!|[[Rtas 'Vadum]]ee<ref name="zone">'''Halo 2''', campaign level ''[[Quarantine Zone (level)|Quarantine Zone]]''</ref>}}

The Quarantine Zone was intended to be a location where the Sentinel custodians of the installation could herd the Flood, and prevent them from entering the Library. Two [[Sentinel manufacturing facility]] ships hung in the air, deploying Sentinel reinforcements.<ref>'''The Official Halo 2 Strategy Guide''', ''page 122''</ref> However, the Quarantine Zone was compromised by the Flood, and the Flood managed to crash one of the floating facilities using a [[Type-26 Wraith]], sending it plummeting down to the installation's surface.<ref name="icon"/>

The Arbiter met with Commander Rtas 'Vadumee and two other Sangheili just outside of the Sentinel wall, and together, they defended a small hill from the Flood before pushing inwards, where the Special Operations Commander had established a small outpost.<ref name="icon"/> There, the Special Operations force held out against waves of Flood attacks from the cliffs before they were reinforced by a pair of Phantoms that dropped off a [[Type-46 Spectre]] and a pair of [[Type-32 Ghost]]s. The Covenant were able to use these vehicles to advance through a large indoor Forerunner facility before entering the first of a series of expansive outdoor arctic canyons. Despite the prowess of the Special Operations Sangheili and the Arbiter, the UNSC were swifter to advance through the Quarantine Zone—''In Amber Clad'' deployed a Pelican dropship that cruised above the battling Flood and Sentinels, cutting directly towards the Library while the Arbiter and his men were forced to fight through waves of Flood, including Flood and the vehicles they had commandeered, while all the while, Enforcers rained heavy fire.<ref name="zone"/>

The small Covenant task force was forced to debark from its vehicles as they transgressed the wreckage of one of the Sentinel constructor factories, although just beyond the wreckage on the other side, they were met by another Covenant Phantom, this one dropping off a Spectre manned by Rtas 'Vadumee himself and another Special Operations Sangheili. However, as they progressed through the last series of snowy plains, they were met with increasingly heavy resistance as they neared the Library. The Sentinels were in much larger force, while a large number of Flood-infested humans savagely held a barricade against the Library, using crates, turrets, and heavy weapons to prevent anyone to gain entrance to the Library and retrieve the index, which would eventually lead to the extermination of the Flood.<ref name="zone"/>

===The Library===
[[File:Miranda and the Index.png|thumb|250px|Miranda Keyes stretches over a chasm in the Library, securing the index.]]
{{Quote|The release of the parasite was unexpected, unfortunate. But, there is no need to panic. In truth, this is a time to rejoice. A moment that all the Covenant should savor... for the Sacred Icon has been found. With it, our path is clear, our entry into the Divine Beyond guaranteed! The Great Journey is nigh... and nothing, not even the Flood, can stop it!|[[Prophet of Truth]]<ref name="gravemind"/>}}

A small UNSC Marine force led by [[Miranda Keyes]] and [[Avery Johnson]] was able to slip past the Flood infestation into the Library, followed shortly by the Arbiter, Rtas 'Vadumee, and half a dozen Special Operations Sangheili. There were a pair of [[anti-gravity gondola]]s, that when activated, autonomously brought their passengers into the upper tiers of the Library, where the index was kept. While the UNSC was first able to seize a gondola, the Covenant were close behind. However, when the Flood began to screech, alerting the Covenant that they were in full force in the bowels of the Library, Rtas 'Vadumee took a pair of Special Operations Sangheili, holding them at the entrance to the gondolas to defend the rest from the Flood as the Arbiter took four Special Operations Sangheili on the second gondola, trailing behind the UNSC-held one. Flood entered the gondolas, jumping from the upper levels and also crawling in underneath on their undersides, assailing both the UNSC troops and the Sangheili forces. Tartarus, in his Phantom, attempted to provide cover fire for the Arbiter, using the three plasma cannons of his dropship to burn off any Flood on the upper levels of the Arbiter's gondola, but later, Tartarus chased after the UNSC-held gondola.<ref name="zone"/>

[[File:H2ATruth2.png|thumb|250px|left|The Prophet of Truth announces the retrieval of Installation 05's activation index.]]
Finally, both gondolas ascended to the top levels of the Library, although the UNSC one arrived first, and a small UNSC force of six soldiers, led by Miranda Keyes and Avery Johnson, entered. Although many [[Flood combat form]]s had been exhausted in the Gravemind's last-ditch attempt to stave off the gondolas, there were a large number of [[Flood infection form]]s prowling the Library which killed off the four UNSC Marines as Keyes and Johnson advanced towards the core of the Library. Meanwhile, the Arbiter silently snuck in behind them. Miranda managed to grab the index over a seemingly endless chasm. Once Keyes and Johnson had the index, they were ambushed by Thel 'Vadamee. Johnson was knocked unconscious by the Arbiter, but Keyes was able to take down Arbiter's shields by [[dual wielding]] [[M7 SMG]]s. However, Tartarus entered with four of his [[Jiralhanae Captain]]s. Tartarus used the [[Fist of Rukt]] to stun Miranda and gravitationally levitate her towards him, draping her over his shoulder and then clasping the index and securing it for himself. Tartarus informed Thel about the Jiralhanae's intended genocide of the increasingly incompetent Sangheili, an act sanctioned by the High Prophets themselves. The Chieftain then knocked the stunned Arbiter into a pit leading to the depths of Installation 05, initiating the [[Great Schism]].<ref name="zone"/>

The engagement at the Library proved to be devastating to the UNSC and resulted in the loss of ''In Amber Clad'' as the Flood took over the frigate. Meanwhile, Tartarus brought the Sacred Icon to ''[[High Charity]]'', where the Prophet of Truth exulted him and encouraged the Covenant to celebrate, for the Sacred Icon was secure, and that soon afterward, the Halos would be fired and the Great Journey would be brought upon the Covenant.<ref name="gravemind"/>

===The Great Schism===
{{Main|Great Schism}}
[[File:H2A-GravemindWithCaptives.jpg|thumb|250px|The Gravemind speaks to the Arbiter and John-117 in the depths of Installation 05.]]
{{Quote|The Elites have failed to protect the Prophets, and in doing so, have put all our lives at risk. Let no warrior forget his oath, 'Thou, in faith, shall keep us safe, whilst we find the Path'. With my blessing, the Brutes now lead our fleets! They ask for your allegiance, and you shall give it.|[[Prophet of Truth]]<ref name="gravemind"/>}}

The Covenant would not activate the Halos unimpeded. The Flood, who would be starved if the rings were activated, would soon attack the Covenant to prevent the activation, and the UNSC, who understood that all sentient life would be erased, also opposed the Covenant. Later, after the fragmentation of the Covenant into the [[Swords of Sanghelios|Sangheili-dominated faction]] and the Prophet-led Covenant, the Sangheili would understand the true purpose of Halo and attack the Covenant to prevent them from activating the ringworld. Meanwhile, [[John-117]], who had fallen into the lake, and the Arbiter, who had been thrust into the chasm of the Library, were both caught by the tentacles of the [[Gravemind]], along with the assimilated [[Prophet of Regret]] and [[2401 Penitent Tangent]], the monitor of Installation 05. The Gravemind sent the Arbiter and John-117 to aid in his plan to prevent the activation of Installation 05, manipulating the Halo's [[teleportation grid]] to send John-117 to ''High Charity'' to search for the index, and sending the Arbiter to the cliffs just beyond the [[Control Room (Installation 05)|Control Room]], another likely spot.<ref name="gravemind"/>

The Covenant's betrayal of the Sangheili led to a large-scale civil war on ''High Charity''. The Covenant politico-military fractures were not restricted to ''High Charity'': they extended to military units across the Covenant, including those on the surface of Installation 05. Upon Truth's order that the Jiralhanae were now the ruling caste of the Covenant, Tartarus ordered the execution of the [[Sangheili Councilor]]s, who had been gathered in the Control Room of Installation 05 for the consecration of the Sacred Icon before the Halos were fired. While most of the Councilors were murdered in cold blood, a small number were taken prisoner by the Jiralhanae.<ref name="uprising">'''Halo 2''', campaign level, ''[[Uprising]]''</ref>

[[File:H2A - Arbiter and 'Vadum.png|thumb|250px|left|Rtas and Thel prepare to avenge the Councilors.]]
However, the Sangheili were quick to strike back. The Gravemind teleported the Arbiter to a high cliff near the Control Room, and gave him an objective: to prevent Tartarus from using the Sacred Icon and activating Halo, which would not result in the promised sublimation event of the Prophets, but only death and destruction on a galactic scale. The Arbiter arrived just too late, witnessing the murders of a handful of Sangheili from afar at the hands of the Jiralhanae, but was able to push forward against a number of patrolling Jiralhanae, and meet up with a number of surviving Sangheili warriors. The small group of survivors, led by the Arbiter, pushed northward through a large Jiralhanae-held Forerunner structure, unpinning small groups of scattered loyal Unggoy and killing dozens of Jiralhanae, Kig-Yar, and Yanme'e. Afterward, they emerged from the structure, and fought their way past several Jiralhanae camps, commandeering several Ghosts along the way. As they neared another cluster of structures, they encountered heavier resistance in the form of Jiralhanae-controlled Wraiths. The Arbiter and his Sangheili allies managed to defeat the Jiralhanae and secure a landing zone, allowing for additional Sangheili reinforcements to arrive.<ref name="uprising"/>

After securing the first half of the camp, the Arbiter and his allies moved into the weapons cache, where the Jiralhanae had aggregated a large number of Covenant and UNSC weapons alike. The Arbiter led his group outside the structure and into a tunnel and defeated the Jiralhanae within. After exiting the tunnel, the Arbiter met with Rtas 'Vadumee who was commandeering a Wraith.<ref name="uprising"/>

===Battle of ''High Charity''===
{{Main|Battle of High Charity}}
[[File:H2A - Great Schism.jpg|thumb|250px|Sangheili and Jiralhanae vessels battle over ''High Charity'' and Delta Halo.]]
John-117 was teleported by the Gravemind directly into the [[High Council Chamber]] of ''High Charity'', where the Prophets of Truth and Mercy addressed the Covenant that the Sacred Icon was secure. Before the Spartan could kill both Prophets, they escaped by means of an [[elevator]], while the doors were locked and waves of [[Jiralhanae Honor Guardsman|Jiralhanae Honor Guardsmen]], [[Jiralhanae Minor]]s, and Unggoy entered in an attempt to kill the supersoldier. Cortana managed to unlock the doors, and John-117 chased through two towers and a set of corridors in pursuit of Truth and Mercy. However, Cortana had discovered Marines that were being kept prisoner on ''High Charity'' and John-117 freed them. Truth's transmissions to the rest of the Covenant allowed Cortana to triangulate his position, allowing her to direct John-117 and the Marines in their hunt for the Prophet. The Covenant attempted to stop Cortana, but were unsuccessful.<ref name="gravemind"/>

As John-117 and the Marines reached [[Hanging Gardens A]], the first scene of Covenant fratricide was seen, as Sangheili Honor Guards, [[Sangheili Minor]]s, [[Mgalekgolo]], and Unggoy fought against Jiralhanae and [[Kig-Yar Sniper]]s amongst the massive plants. John-117 and his men advanced to the [[Mid Tower]], where Rangers and Special Operations Sangheili entered the fray, and numerous [[Yanme'e]] entered the engagement. During the fight, the Flood-controlled ''In Amber Clad'' then jumped directly into ''High Charity'', where it plummeted uncontrollably, crashing into the [[Far Tower]]. However, by the time that the small UNSC squad entered [[Hanging Gardens B]], Sangheili resistance on ''High Charity'' had broken. In the second Hanging Gardens, the Sangheili and those loyal to them fell back, leaving behind large numbers of [[stationary shield generator]]s, abandoning numbers of Unggoy to berserk Jiralhanae as the Sangheili fell back to the Far Tower and the [[Mausoleum of the Arbiter]], drawing a last line of defense there. Despite their efforts, the Prophets of Truth and Mercy, Tartarus, and a handful of Jiralhanae Captains were able to tunnel through the last Sangheili defenses to the far docking bays of the Far Tower.<ref>'''The Official Halo 2 Strategy Guide''', ''page 129''</ref> John-117 pursued Tartarus, fighting through the Far Tower and the Mausoleum of the Arbiter to make it through to the landing pads.<ref name="gravemind"/><ref>'''The Official Halo 2 Strategy Guide''', ''page 128''</ref>

[[File:H2A - Mercydeath.png|thumb|250px|left|The Prophet of Mercy is killed by the Flood.]]
The Spartan was too late, however. The Prophet of Truth ordered Tartarus to deliver the activation index to the Control Room of Installation 05, and activate the Halos. Tartarus took a detachment of Jiralhanae Honor Guards along with him in two Phantoms, along with UNSC prisoners Avery Johnson and Miranda Keyes. Truth and Mercy took a third Phantom to the [[Forerunner Dreadnought]]—the central energy source of ''High Charity'', and also a fully functional Forerunner [[keyship]] that the two remaining High Prophets were going to use to reach Earth, and finish the battle. Meanwhile, the Flood were escaping from the crashed hulk of ''In Amber Clad''. They seeped out of the rents in its hull armor and commandeered its Pelican dropships, sending them over the surface of ''High Charity'', crashing into the floors and releasing [[Flood combat form|combat forms]], and spilling infection forms out of the air from opened hatches. The Prophet of Mercy was beset by an infection form and died before he could reach his Phantom. However, Tartarus and Truth were able to depart before John-117 could arrive.<ref name="gravemind"/>

[[File:H2A - Cortana watching dreadnought.jpg|thumb|250px|Cortana watches the keyship lift off from ''High Charity'' for Earth.]]
By that time, resistance by the Sangheili and their allies had completely shattered on ''High Charity''. There were few Sangheili or Mgalekgolo remaining, and only a few scattered Unggoy. The forces loyal to the Prophets, however, retained a large number of Jiralhanae, Kig-Yar, and Yanme'e. Despite the lack of a Sangheili ground force, they were still very much present in space, where the Covenant fleets over ''High Charity'' had splintered in allegiances, with Sangheili and Jiralhanae ships actively engaging and destroying each other. While Truth was taking a Phantom to the Forerunner ship, Cortana detected an [[High Charity conduit|energy conduit]] to the ship located in the Mausoleum tower ahead of John-117's position. John-117 entered the Mausoleum tower from the dropship landing pads, and engaged numerous Flood and Covenant hostiles. The Spartan eventually took a [[gravity lift]] to access the [[Sanctum of the Hierarchs]]. While John engaged Covenant forces, large numbers of Flood began to attack and the Spartan was forced to enter the energy conduit to reach the Forerunner ship. John-117 was able to jump in the conduit just in time, barely making it to the ship before it lifted off for Earth. However, Cortana stayed behind while John would attempt to neutralize the ship before it rallied the Covenant fleets at Earth. In the event that Tartarus was about to trigger the Halo Array, Cortana announced that she would detonate the fusion reactors of ''In Amber Clad''—just like she had done to the {{UNSCShip|Pillar of Autumn}} at [[Installation 04]]—and the blast would destabilize the ring and prevent the activation of the Halos.<ref name="charity">'''Halo 2''', campaign level, ''[[High Charity (level)|High Charity]]''</ref>

Shortly afterward, all Covenant resistance on ''High Charity'' broke and succumbed to the Flood, who had infested a large area of the planetoid even during the raging combat between the Covenant and the Flood. Cortana, who resided in ''High Charity'''s computer systems to be ready to detonate the frigate's reactors as a final fail-safe, was captured and interrogated by the Gravemind.<ref name="journey">'''Halo 2''', campaign level ''[[The Great Journey]]''</ref>

===Assault on the Bastion of the Brutes===
[[File:H2A - Scarab console.jpg|thumb|250px|left|Avery Johnson controlling a Scarab before the Arbiter.]]
Meanwhile, Rtas 'Vadumee informed the Arbiter that Tartarus was within the Control Room, and would soon be activating the Halos. However, the doors to the Control Room were nearly completely impenetrable, and would only be opened by the firing of the main cannon of a [[Type-47 Scarab]] walker. Fortunately, a Scarab was available at the [[Bastion of the Brutes]], a Forerunner structure used by the Jiralhanae as their local base of operations.<ref name="uprising"/><ref name="journey"/>

While Rtas 'Vadumee advanced forward in a Wraith tank, the Arbiter and another Special Operations Sangheili took a Spectre, and together, the Sangheili battled through a swarm of Ghosts, several Wraiths, and a bombarding Phantom. Eventually, the Sangheili secured entrance into the Bastion of the Brutes, where the Arbiter found another Special Operations Sangheili and a pair of Mgalekgolo, all of whom were loyal to the Sangheili. Meanwhile, Rtas 'Vadumee said that he would briefly watch the Arbiter's back, and would prevent any Jiralhanae reinforcements from entering in behind them while they cleared out the stronghold. Later, he announced that he would retake the {{Class|CCS|battlecruiser}} that was hanging in the distance. The Arbiter and his band of Sangheili and Mgalekgolo stormed the Bastion, fighting their way past Jiralhanae, Kig-Yar, Yanme'e, and even a Phantom. Eventually, they freed imprisoned Councilors and Mgalekgolo and eventually reached the platform where the Scarab was docked. Much to their surprise, they discovered the presence of humans who were being held prisoner by the Jiralhanae. Amongst the prisoners was Sergeant Avery Johnson. The Jiralhanae had just received orders from Tartarus to execute the prisoners, when the Arbiter and his followers attacked. The humans, with the help of their Sangheili allies-to-be, took advantage of this distraction to free themselves and take control of the Scarab.<ref name="journey"/>

After all the Jiralhanae on the platform were dead, there was a brief standoff between the Sangheili and the UNSC personnel. However, both the Arbiter and Sergeant Johnson realized that they shared a common enemy and objective. The two sides begrudgingly joined forces and set out to stop Tartarus from activating Halo.<ref name="journey"/>

===The Control Room===
[[File:H2A - Tartarus with Rukt.jpg|thumb|250px|Tartarus preparing to attack.]]
The Arbiter took possession of a Banshee and provided cover fire for Johnson's Scarab. Together, they fought their way past a large Jiralhanae force consisting of multiple Wraiths, Banshees, Spectres, and Shade turrets. Eventually, the group reached the [[Control Room (Installation 05)|Control Room]] and destroyed its doors with the Scarab's primary cannon. Inside the chamber, the Arbiter fought his way through numerous Jiralhanae forces who had been ordered to prevent the Arbiter from disturbing Tartarus while he activated the Halos. Despite reinforcements, the high-ranked Jiralhanae were unable to hold the room, and the Arbiter continued down an arched corridor before confronting Tartarus in the control room. Inside, he found Tartarus and several Jiralhanae, along with two prisoners—Miranda Keyes and [[343 Guilty Spark]] who had been captured by the Covenant during the [[raid on the Threshold gas mine]].<ref name="journey"/>

Tartarus had been trying to force Keyes to insert the index into its place, as only a [[Reclaimer]] could activate Halo. The Arbiter entered the control room and told the Chieftain to stand down. Tartarus refused, and his Jiralhanae were about to attack the Arbiter, when Johnson suddenly appeared, pointing a [[Type-50 particle beam rifle]] at Tartarus' head. Seeing that he was in danger, Tartarus ordered his Jiralhanae to hold back for the moment. The Arbiter had Guilty Spark explain were weapons of mass destruction, built by the Forerunners as a last resort means to stop the Flood and ultimately led to the Forerunners' downfall. Despite Guilty Spark's revelations, Tartarus—blinded by his loyalty to the Prophets and his hatred for the Sangheili—refused to listen. The Chieftain threw Guilty Spark at Johnson, knocking him out for a moment. He then physically forced the Sacred Icon into Miranda Keyes' hand and shoved it into the receptacle, beginning the activation of Installation 05. Miranda jumped out of the way of the imminent firefight as the Arbiter, the conscious Johnson, and a small cluster of recently-arrived [[Sangheili Zealot]]s and Councilors, charged at Tartarus and his guard of four Jiralhanae Captains. The Jiralhanae guards were quickly slain, and Tartarus retreated onto the three-level structure at the center of the control room. When the Arbiter and his allied Zealots and Councilors pursued, they found to their dismay that Tartarus was protected by a nearly impenetrable energy shield. Only Sergeant Johnson, with his particle beam rifle, could disable Tartarus' shields, and only for a few seconds.<ref name="journey"/>

Meanwhile, Miranda Keyes argued with Guilty Spark and eventually forced him to reveal that the firing sequence could be stopped if the Reclaimer simply removed the index from the its position. However, she could not do anything while Tartarus was still alive. The Arbiter and Sangheili battled Tartarus, who used his massive [[Type-2 gravity hammer|gravity hammer]], the [[Fist of Rukt]], to slay many high-ranking Sangheili. Eventually, the Arbiter succeeded in killing Tartarus. Commander Keyes immediately leapt to action after Tartarus died, snatching the index from the control panel. Despite the fact that Installation 05 was primed to fire, the removal of the index only triggered a partial firing, one that was inconsequential and led to the loss of no life whatsoever. However, 343 Guilty Spark informed them that because of the partial activation of Installation 05, the other five remaining installations were set onto standby mode, and were ready to fire upon command from a central Forerunner installation: [[Installation 00|the Ark]].<ref name="journey"/>

===Final space battle===
Despite the isolated Sangheili ground victory on Installation 05, there was a much greater threat: the Flood. Having assumed dominance over the whole of ''High Charity'' and certain locations on Installation 05, they tried boldly expanding into space, attempting to take over Covenant warships. The ambitious [[Sangheili Major]] [[Voro Nar 'Mantakree|Voro 'Mantakree]] assumed command of the {{Class|Reverence|cruiser}} ''[[Incorruptible]]'' after mutinying against and killing his insane commander, [[Tano 'Inanraree]],<ref>'''Halo: Ghosts of Onyx''', ''page 192''</ref> and audaciously sent a fleetwide dispatch to the idling Covenant fleet amassed over ''High Charity'': the Flood were lifting off from Installation 05 in [[Type-25 Spirit]] dropships and Banshees, and were attempting to attack and take control of Covenant warships to spread throughout the galaxy. The fleets were united after the transmission, and four [[Covenant destroyer]]s, including the ''[[Rapturous Arc]]'', that were about to be consumed by the Flood were burned and destroyed to prevent the parasite from capturing the warships.<ref>'''Halo: Ghosts of Onyx''', ''page 197''</ref>

Shortly afterward, however, the fleets splintered without a common foe. The [[Jiralhanae Chieftain]] [[Gargantum]] attempted to coordinate a Jiralhanae uprising against the Sangheili, and chased after 'Mantakree with four [[Covenant frigate]]. Using deft tactics and maneuvering out the Sangheili carrier ''[[Lawgiver]]'', the ''Incorruptible'' destroyed the Jiralhanae-controlled frigate ''[[Tenebrous]]'', although the three remaining frigates, including Gargantum's personal frigate, the ''[[Twilight Compunction]]'', continued pursuing him. Soon afterward, the entire Covenant fleet began turning on itself, following Gargantum's example. The {{UNSCShip|Dusk}}, one of the five UNSC ships originally sent to tail ''Solemn Penance'', witnessed the massive encounter as Covenant ships turned upon one another and destroyed themselves in a civil war.<ref name="goo199">'''Halo: Ghosts of Onyx''', ''page 199''</ref>

However, ''Incorruptible'' did not continue in the orbital battle, as a revered Sangheili fleet commander, [[Imperial Admiral]] [[Xytan 'Jar Wattinree]], urged all Sangheili to regroup over the outpost world [[Joyous Exultation]] of the [[Salia system]]. 'Mantakree obediently left the battle, entering slipspace towards Joyous Exultation. During the pursuit, SPARTAN-II [[Blue Team]] dropped in the midst of the chase as the ''Incorruptible'' prepared to leave the system, in their captured Covenant destroyer, ''[[Bloodied Spirit]]''. Gargantum was incensed that heretic "Demons" had seized a Covenant warship, and diverted one of the three pursuit frigates from the ''Incorruptible'' to the ''Bloodied Spirit''. The frigate managed to lower the UNSC-controlled destroyer's shields before the SPARTAN-IIs jumped to slipspace for the [[Zeta Doradus system]]. The Sangheili defeated the Jiralhanae fleet and subsequently held ''High Charity'' in quarantine.<ref name="11thhour">'''[[Eleventh Hour reports]]''', ''Part 5''</ref> However, this largely failed, due to the Gravemind sending the ''[[Indulgence of Conviction]]'', controlled by the Flood, to Earth, in the hopes of infecting it and weakening the Sangheili ships in orbit around the Flood hive. This was successful and the Gravemind was able to leave Installation 05's space and find the Ark.<ref name="floodgate">'''Halo 3''', campaign level ''[[Floodgate]]''</ref>

==Aftermath==
[[File:H2A-SevenRings.jpg|thumb|250px|343 Guilty Spark informs the Arbiter, Johnson, and Keyes about the Ark.]]
The battle at [[Installation 05]] was extremely costly with significant political-military consequences for the [[Covenant]] and remarkable ramifications for all sentient life in the galaxy. Thousands of Covenant forces were slain in [[John-117]]'s mission to kill the [[Prophet of Regret]],<ref name="regret"/> the race to acquire the [[activation index]] from the [[Control Room (Installation 05)|Control Room]], and the massive ground and orbital battles that took place on Installation 05, ''[[High Charity]]'', and between the Covenant fleets orbiting over [[Substance]] because of the [[Great Schism]].<ref name="goo199"/>

[[UNSC]] losses were remarkably lower because of the small number of forces they brought into the theater of operations, almost solely the crew and soldiers of {{UNSCShip|In Amber Clad}}. Hundreds of [[UNSC Marine Corps|Marines]] and [[Orbital Drop Shock Troopers]], however, were lost in UNSC ground operations: the assassination of Regret and the storming of the [[Quarantine Zone]]. A large number were also infected by the Flood and made continual appearances as [[Flood combat form|combat forms]] in the [[Sentinel wall]], Quarantine Zone, and Flood-infested ''High Charity''.<ref name="gravemind"/> The crewmen of the ''In Amber Clad'' were presumably killed and reanimated by the Flood as well. However, the UNSC suffered the least amongst the four warring factions in the Battle of Installation 05. In many ways, Installation 05 was the true turning point in the [[Human-Covenant War]]. In the long term, the political chaos wrought throughout the battle would shatter the Covenant Empire into [[Covenant remnants|warring factions]]. The Sangheili eventually allied themselves with their human enemies, bolstering their fleets and taking their military expertise away from the Covenant. The immediate loss of ''High Charity'' and the majority of its enormous [[High Charity defense fleet|defense fleet]] drastically reduced the threat of the Covenant to human space. While still dangerous, the Covenant forces loyal to the Prophets ultimately proved incapable of defending themselves over the last few weeks of the war.<ref>'''Halo 3''', campaign level ''[[The Covenant (level)|The Covenant]]''</ref>

[[Sentinel]] defenses were completely trampled over, particularly in the Quarantine Zone, where within hours, the Flood had managed to infiltrate the well-defended Sentinel wall and seize control of large tracts of the Quarantine Zone, even grounding an airborne [[Sentinel manufacturing facility]].<ref name="icon"/> The Flood also permeated the [[Library]] and the surrounding grounds, eliminating almost all Sentinels from the skies, leaving only scattered [[Enforcer]]s to do battle with them. The Flood also controlled UNSC and Covenant vehicles alike, reinforcing their considerable ranks with [[M808B Scorpion]] tanks, [[M12 Warthog LRV]]s, [[Type-26 Wraith]] tanks, and [[Type-32 Ghost]] assault vehicles. Flood losses were initially high because of the Arbiter's actions in the Quarantine Zone and John-117's on ''High Charity''. However, it was inconsequential: the Flood scored a notable victory on ''High Charity'', capturing the Covenant's mobile home planetoid and [[terraforming|transforming]] the structure into a [[Flood hive]].<ref name="charity"/>

===Fragmentation of the Covenant===
[[File:H2A Beamish cameo.jpg|thumb|250px|left|Kig-Yar and Unggoy protesting on ''High Charity''.]]
The Covenant was fractured, with the Sangheili rallying those loyal to them against the [[San'Shyuum]] and [[Jiralhanae]], who controlled the military of the Prophet-led Covenant against the Sangheili and their allies. Many San'Shyuum were killed in the battle, either during the Flood's infestation of ''High Charity'', or on Installation 05 as many [[Minister (title)|Ministers]] and Prophets travelled to the ring to examine it for themselves. The Prophets' betrayal of the Sangheili led to the divide of the Covenant species. Many [[Mgalekgolo]] allied themselves with the Sangheili, the [[Unggoy]] followed their commanders, and the [[Kig-Yar]] aligned themselves with whoever would lead them to profit.<ref>'''[[Halo: Evolutions]]''', "[[Wages of Sin]]", ''pages 300-301''</ref>

The Covenant [[High Council|ruling system]] was destabilized, with the death of the [[Prophet of Regret]] on Installation 05 at the hands of [[John-117]] and the death of the [[Prophet of Mercy]] on ''High Charity'' due to Flood infestation.<ref name="gravemind"/><ref name="regret"/> The [[Prophet of Truth]] held dictatorial power, with several subservient [[Lesser Prophet]]s, completely re-shifting the political dynamics of the Covenant. The Jiralhanae held reign over the majority of the [[Covenant military]], bringing their innate tenaciousness and ferocity to the front lines quite unlike the Sangheili. The Jiralhanae also assumed more lower-level Covenant military authority, now replacing the Sangheili as the leaders of field squads and teams. The Jiralhanae also introduced a unique set of bloodthirsty weaponry into the Covenant's field arsenals. The [[Covenant fleet]] was believed to lose quite a bit of its technical proficiency without the innate technical knowledge of the Sangheili.<ref>'''Halo: Ghosts of Onyx''', ''page 194''</ref>

===Return to Earth===
[[File:H2A - Earth and Dreadnought.jpg|thumb|250px|The Forerunner ship approaching a besieged Earth as the [[UNSC Home Fleet]] continues to fight against Covenant fleets.]]
{{Quote|no=two|1=Terrence Hood|q1=Master Chief? Mind telling me what you're doing on [[Forerunner Dreadnought|that ship]]?|2=John-117|q2=Sir. Finishing this fight.|3=Admiral Terrence Hood and John-117<ref name="journey"/>}}

In the end, the fates of the Covenant fleets over ''High Charity'' is unknown, although at least one Covenant vessel, the ''Incorruptible'', escaped. 'Matrankee was commended for his actions against the Flood on Installation 05, and was promoted to [[Fleet Master]].<ref>'''Halo: Ghosts of Onyx''', ''page 243''</ref> The Flood continued to attempt to escape ''High Charity'' in Covenant starships, and a fleet led by [[Rtas 'Vadum]] on the ''[[Shadow of Intent]]'' held the line against the Flood. However, the Flood managed to infest at least one Sangheili-controlled ship, the ''Indulgence of Conviction'', a {{Class|CCS|battlecruiser}}, and made a [[Slipstream space|slipspace]] jump to [[Earth]] to attempt to infest the human homeworld. The Sangheili fleet in orbit over ''High Charity'' followed the Flood-controlled cruiser, and when the Flood ship crash-landed on Earth, Rtas 'Vadum and his forces aided the [[UNSC Home Fleet]] in destroying the Flood vessel and terminating the Flood spread across the planet. However, prior to this, ''High Charity'' had already left its orbit around Installation 05, and according to a scrambled distress signal from [[Cortana]], was already on its way to Earth to enter the [[Portal at Voi|Portal]].<ref name="floodgate"/> It was indicated though that all of the other Flood-controlled ships were destroyed though: upon landing on Earth an Sangheili informed the Arbiter that the Sangheili's fleet had taken care of all of the Flood-controlled ships, except for the one which had managed to break through and jump to Earth. It can be inferred that the Flood-controlled ships were ultimately all destroyed except the one intercepted on Earth and ''High Charity'' which was later destroyed by the Master Chief in the [[Battle of Installation 00]]. [[Cortana]] was left to the clutches of the Gravemind. It was later shown that she answered a few questions to buy herself some time and used the opportunity to help find a way to destroy the Flood. She would later be rescued by the Master Chief who would then destroy ''High Charity'' during the [[Raid on High Charity|Raid on ''High Charity'']].<ref>'''Halo 3''', campaign level ''[[Cortana (level)|Cortana]]''</ref>

John-117 was aboard Truth's [[Forerunner Dreadnought]], which managed to reach Earth unharmed and landed in [[Africa]], near the [[Portal at Voi|Portal to the Ark]], about two weeks after its departure from ''High Charity''.<ref>'''Halo 3''', campaign level ''[[Tsavo Highway (level)|Tsavo Highway]]''</ref> {{UNSCShip|Dusk}} eventually withdrew to rendezvous with [[Carl Patterson|Admiral Patterson]]'s [[Patterson's battle group|battlegroup]] outside of the [[Zeta Doradus system]],<ref>'''Halo: Ghosts of Onyx''', ''page 294''</ref> and the UNSC ''In Amber Clad'' remained crashed into one of the towers of ''High Charity''.

==Timeline==
'''October 20, 2552'''
*The [[Battle of Earth]] begins between the [[UNSC Defense Force]] and the [[Covenant]]'s [[Fleet of Sacred Consecration]].<ref name="cairo"/>
*UNSC forces heavily outnumber Covenant forces and the [[Prophet of Regret]] orders a retreat.<ref name="metro"/>
*With Regret aboard, the {{Class|CAS|assault carrier}} ''[[Solemn Penance]]'' makes an emergency [[slipspace]] jump over [[New Mombasa]], followed by {{UNSCShip|In Amber Clad}}, [[UNSC Coral Sea|''Coral Sea'']], [[UNSC Dusk|''Dusk'']], [[UNSC Paris|''Paris'']], and [[UNSC Redoubtable|''Redoubtable'']].<ref name="metro"/>

'''November 2, 2552'''
*''Solemn Penance'' and ''In Amber Clad'' exit slipspace in the [[Coelest system]] over [[Substance]] and near [[Installation 05]].
*The Battle of Installation 05 begins.<ref name="deltahalo"/>
*''Solemn Penance'' deploys ground forces to the surface of the installation and Regret occupies a [[Temple (Installation 05)|Forerunner temple]].<ref name="regret"/>
*Regret sends out a distress signal and apology to the rest of the [[High Council]], which the [[Prophet of Truth|Prophets of Truth]] and [[Prophet of Mercy|Mercy]] reluctantly accept.<ref name="regret"/>
*[[John-117]] is deployed to the installation's surface, along with several [[Orbital Drop Shock Troopers]]. The UNSC forces fight their way to Regret's position.<ref name="regret"/>
*''[[High Charity]]'', its [[High Charity defense fleet|defense fleet]], and the [[Second Fleet of Homogeneous Clarity]] arrive in the system.<ref name="regret"/>
*[[Rtas 'Vadum]]ee sends [[Type-52 Phantom]]s to rescue Regret, but Truth belays the order.<ref name="regret"/><ref name="icon"/>
*John assassinates the Prophet of Regret inside the temple and retreats at ''Solemn Penance'' attempts to kill him. The Spartan is captured by the [[Gravemind]].<ref name="regret"/>
*The [[Sangheili]]'s "failure" to protect Regret leads to the [[Changing of the Guard]], as [[Jiralhanae]] occupy Sangheili positions.<ref name="icon"/>

'''November 3, 2552'''
*[[Arbiter]] [[Thel 'Vadam]]ee and [[Tartarus]] are sent to retrieve Installation 05's [[activation index]]. The Arbiter successfully takes the index, but Tartarus tries to kill him and takes the index from him, having been secretly ordered to do so by the Prophet of Truth.<ref name="zone"/>
*Most of the [[Sangheili Councilor]]s are taken to the surface of Installation 05 where they are murdered by the [[Jiralhanae]].<ref name="uprising"/>
*The Prophet of Truth transfers command of the [[Covenant military]] to the Jiralhanae, while Tartarus declares war on the Sangheili, and the [[Battle of High Charity|Battle of ''High Charity'']] begins. Fighting between Sangheili and Jiralhanae forces breaks out all over ''High Charity''. As word spreads, fighting takes place throughout the fleet, as Sangheili and Jiralhanae controlled ships attack one another.<ref name="gravemind"/>
*The [[Flood]] invade ''High Charity'' during the battle, entering the city's dome via precision [[Slipstream space|slipspace]] jump aboard ''In Amber Clad'' and its embarked [[D77-TC Pelican|Pelicans]]. The Prophet of Mercy is attacked by an [[Flood infection form|infection form]] and abandoned by the Prophet of Truth, who now reigns as the Covenant's sole leader.<ref name="gravemind"/>
*Tartarus attempts to activate Installation 05 by forcing [[Miranda Keyes|Commander Miranda Keyes]] to insert the Index into the Control Room's [[The Core|Core]].<ref name="journey"/>
*Thel 'Vadamee, with the aid of [[Avery Johnson|Sergeant Johnson]] and Rtas 'Vadumee, kills Tartarus.<ref name="journey"/>
*Commander Keyes aborts the activation of Installation 05, placing the entire [[Halo Array]] on standby status. [[343 Guilty Spark]] reveals the existence of [[Installation 00|the Ark]].<ref name="journey"/>
*The Flood takes control of ''High Charity'' and many of its warships. Jiralhanae and Sangheili fleets remaining around the city-station continue to destroy each other.<ref name="journey"/>
*The Prophet of Truth departs ''High Charity'' for Earth aboard the [[Forerunner Dreadnought]], to join the [[Battle of Earth]], with John-117 aboard.<ref name="journey"/>
*The [[prowler]] ''[[UNSC Dusk|Dusk]]'' witnesses the battle between Sangheili and Jiralhanae held ships above Delta Halo, both fighting each other pausing only to escalate an immediate outbreak of the Flood from the ringworld. ''Dusk'' subsequently flees the battle and links up with [[Patterson's battle group]] at Earth.<ref name="goo199"/>
*[[Sangheili Major]] [[Voro Nar 'Mantakree|Voro 'Mantakree]] kills his [[shipmaster]], [[Tano 'Inanraree]], while he is attempting to allow the Flood] to enter the ship. He then assumes command of the ship, ''[[Incorruptible]]'', and becomes the ''de facto'' leader of the [[Second Fleet of Homogeneous Clarity]]. He leads his new forces to [[Joyous Exultation]], pursued by the [[Jiralhanae]] [[Gargantum]] and his ships.<ref name="goo189"/>

'''November 4, 2552'''
*[[Swords of Sanghelios|Thel 'Vadam's forces]] [[glassing|glass]] Installation 05's surface to neutralize the Flood.<ref name="11thhour"/>
*The Battle of Installation 05 ends.

==Participants==
{{Col-begin}}
{{Col-2}}
===UNSC===
====Personnel====
*[[Miranda Keyes|Commander Miranda Keyes]]
*[[Richard Lash|Commander Richard Lash]]
*[[Julian Waters|Lieutenant Commander Julian Waters]]
*[[Xaing Cho|Lieutenant Commander Xaing Cho]]
*[[Bethany Durruno|Lieutenant Bethany Durruno]]
*[[Joe Yang|Lieutenant Joe Yang]]
*[[John-117|Master Chief Petty Officer John-117]]
*[[Avery Johnson|Sergeant Major Avery Johnson]]
*[[Marcus Stacker|Gunnery Sergeant Marcus Stacker]]
*[[Banks|Staff Sergeant Banks]]
*[[Perez (Marine)|Corporal Perez]]
*[[Chips Dubbo|Private First Class Chips Dubbo]]
*[[McKenzie (Marine)|Private McKenzie]]
*[[Cortana]]

====Ships====
*{{UNSCShip|In Amber Clad}}
*{{UNSCShip|Coral Sea}}
*{{UNSCShip|Dusk}}
*{{UNSCShip|Paris}}
*{{UNSCShip|Redoubtable}}

===Forerunner constructs===
*[[343 Guilty Spark]]

===Flood===
*[[Gravemind]]
*[[2401 Penitent Tangent]] {{C|captured}}

{{Col-2}}
===Sangheili-led forces===
====Personnel====
*[[Arbiter]] [[Thel 'Vadam]]
*[[Special Operations Commander]] [[Rtas 'Vadum]]
*[[Sangheili Councilor|Councilor]] [[Duru 'Scoahamee]]
*Councilor [[K'hurk 'Bornisamee]]
*Councilor [[Torg 'Gransamee]]
*[[Shipmaster]] [[Tano 'Inanraree]]
*Shipmaster [[D'ero 'S'budmee]]
*Commander [[G'torik 'Klemmee]]
*[[Sangheili Major|Major]] [[Voro Nar 'Mantakree|Voro 'Mantakree]]
*[[Zo Resken]], the Prophet of Clarity
*[[Tilik 'Bornisamee]]
*[[Uruo 'Losonaee]]
*[[Zasses 'Jeqkogoee]]
*[[Y'gar 'Pewtrunoee]]
*[[Paruto Xida Konna]]
*[[Waruna Xida Yotno]]
*[[Crun 'Brinsmee]]
*[[Tul 'Imjanamee]]
*[[Sluggish Drifter]]

====Ships====
*''[[Incorruptible]]''
*''[[Indulgence of Conviction]]''
*''[[Journey's Sustenance]]''
*''[[Lawgiver]]''
*''[[Rapturous Arc]]''

===Covenant===
====Personnel====
*[[Prophet of Truth|High Prophet of Truth]]
*[[Prophet of Mercy|High Prophet of Mercy]]
*[[Prophet of Regret|High Prophet of Regret]]
*[[Prophet of Exquisite Devotion]]

*[[Chieftain of the Jiralhanae|Chieftain]] [[Tartarus]]
*[[Shipmaster]] [[Gargantum]]
*[[Jiralhanae Captain|Captain]] [[Melchus]]

====Ships====
*''[[Revenant (ship)|Revenant]]''
*''[[Solemn Penance]]''
*''[[Tenebrous]]''
*''[[Twilight Compunction]]''
{{Col-end}}

==Gallery==
<gallery>
File:H2 Hard Drop.jpg|Covenant Shade turrets open fire on the inbound HEVs.
File:TanODST.jpg|ODSTs battling on Delta Halo.
File:H2 Regret Holy Wind.jpg|Cortana and John-117 learn that Regret plans to activate Installation 05.
File:H2 Miranda Index.jpg|Commander Keyes coordinates a plan with Cortana and John-117 to take the index from the Library.
File:H2 Sacred Icon Revealed.jpg|Guilty Spark projects an image of the "Sacred Icon" to Truth on ''High Charity''.
File:H2 Main Temple Vaporized.jpg|''Solemn Penance'' repositions over the temple in an attempt to kill John.
File:Halo6.jpg|Tartarus' Phantom descends towards the surface of Installation 05.
File:H2 Arbiter Ready.jpg|The Arbiter readies himself before the insertion.
File:Enforcer.jpg|The Arbiter fights against a Forerunner Enforcer.
File:H2 Arbiter and Rtas QuarantineZone.jpg|The Arbiter and 'Vadumee plan to find the icon.
File:H2 gondola librarymove.jpg|The two gondolas race to reach the top floors of the Library.
File:H2 Arbiter Gondola Phantom.jpg|Tartarus's Phantom hovers over the Arbiter's gondola, defending him from the Flood.
File:H2A-HowYaDoing.jpg|The Arbiter grabs Avery Johnson before knocking him unconscious.
File:H2 Tartarus Betrays Arbiter.jpg|Tartarus betrays the Arbiter.
File:H2 Cortana Gravemind Prisoner.jpg|Cortana captured by the Gravemind at the heart of Flood-infested ''High Charity''.
File:H2 Tartarus Leads.jpg|Tartarus leads Miranda Keyes and 343 Guilty Spark deeper into the bowels of the Control Room.
File:H2A - Cortana.png|Cortana, under the clutches of the Gravemind.
</gallery>

==List of appearances==
*''[[Halo 2]]'' {{1st}}
*''[[Halo: Ghosts of Onyx]]''
*''[[Halo 3]]'' {{Mo}}
*''[[Halo: Evolutions - Essential Tales of the Halo Universe]]''
**''[[Wages of Sin]]''
*''[[Halo: Broken Circle]]''
*''[[Halo 2 Anniversary]]''

==Sources==
{{Reflist|2}}

{{Human-Covenant War}}

{{DEFAULTSORT:Installation 05}}
[[Category:UNSC Victories|Installation 05]]
[[Category:Installation 05]]