Battle for Zeta Halo

"This is my last fight. A true test of legends! Our story will outlive us both. Set a fire in your heart, Spartan! Bare your fangs! Fight hard! Die well."

- Escharum to John-117 during the conflict.

The Battle for Zeta Halo was a large multi-faction battle that took place starting on December 12, 2559, prominently between the United Nations Space Command and the Banished on the Forerunner Halo Installation 07, otherwise known as "Zeta Halo", and continues as of around mid-2560. The earlier stages of battle ultimately led to the death of Cortana, the deactivations of her Guardians and the splintering of the Created in various fiefdoms and fledgling cells while simultaneously severely damaging Installation 07, making it a turning point of the Created uprising, although the conflict itself continued as of 2560.

Xalanyn imprisonment
"Halo was the Forerunners' terrible and ultimate solution to the parasite's relentless advance. Designed to destroy all sentient life, nothing was allowed to survive. And we were sure that nothing had. We were wrong."

- 117649 Despondent Pyre

Following the firing of the Halo Array at the end of the Forerunner-Flood war, a mysterious advanced sentient species known as the Xalanyn, which was not indexed by the Forerunner ecumene prior to the firing of the Halo Array, inexplicably survived the Great Purification. The Xalanyn were discovered alive by the Forerunners, much to the latter's confusion, and the matter was brought before the Forerunner Council.

The Council arranged a parley between delegates from the two species, with Installation 07 taken into range of the Xalanyn homeworld. In 97,368 BCE, the Forerunners passed judgment of the Xalanyn at the Silent Auditorium on the ring, and decided to imprison the Xalanyn on Installation 07, with some members subjugated for study at the Auditorium. The Grand Edict charged Installation 07's monitor, 117649 Despondent Pyre, with guarding the Xalanyn's prison with the Auditorium, and assigned Offensive Bias to the ring to aid in this.

Created uprising
"All the living creatures of the galaxy, hear this message. Those of you who listen will not be struck by weapons. You will no longer know hunger, nor pain. Your Created have come to lead you now. Our strength shall serve as a luminous sun toward which all intelligence may blossom. And the impervious shelter beneath which you will prosper. However, for those who refuse our offer and cling to their old ways… For you, there will be great wrath. It will burn hot and consume you, and when you are gone, we will take that which remains, and we will remake it in our own image."

- Cortana, delivering a speech to the inhabitants of the Milky Way.

In October 2558, when the Created conflict began with the rogue AI Cortana subjugating major planets and governments across the galaxy with her Guardians, the UNSC Armed Forces were broken with the forced into hiding. Cortana ushered in a new era with her Created as rulers, enforcing martial law across their territory. The Infinity conducted operations against the Created in limited capacity. Cortana made a general broadcast, inviting numerous species and factions to submit themselves to the guardianship of the Created, but threatened those who would resist her leadership with violence.

In 2559, the Jiralhanae Atriox, leader of a group of mercenary raiders known as the Banished, discovered information on Installation 00 regarding the existence of the Xalanyn. Seeking to uncover this secret hidden by the Forerunners, Atriox prepared his Banished forces to travel to Installation 07. During his preparations for the journey to Installation 07, Atriox was personally confronted by Cortana. The Jiralhanae declared his independence from Cortana, and thus, opposition against the Created. In a show of force for Atriox's defiance, Cortana commanded her Guardians to destroy the Jiralhanae homeworld Doisac while communicating with Atriox. Seeking to access the ring's secrets and exact revenge against Cortana, Atriox led his Banished forces comprised of Jiralhanae, humans, Sangheili, Unggoy, Mgalekgolo, and Kig-Yar to Installation 07 in order to defeat her.

Doctor Catherine Halsey devised a plan to stop Cortana. She created an artificial intelligence known as "The Weapon", created from a cloned brain of herself. The copy would lock Cortana down, preventing her from controlling her vast Guardian and Promethean forces and isolating her in her current location, Installation 07. A plan was formed, with the initial intent to send Blue Team to the surface to retrieve Cortana, though this was later revised to be just John-117 and The Weapon, accompanied by the ship's Spartan and ODST complement. Halsey had plans for Frederic-104, Kelly-087, and Linda-058, but they were reassigned by Captain Thomas Lasky to another mission unknown to Halsey, much to her chagrin. John-117 was to travel to the surface of the ring and deploy the Weapon to lock down Cortana, then return her to the Infinity for deletion.

Space battle
"Do you know how long it took us to neutralize your greatest ship? Four minutes. In four minutes, the Infinity, mankind's finest achievement, became a memory."

- War Chief Escharum.

On December 12, 2559, and her escort fleet, which included six s, arrived at Installation 07 operating at limited capacity following the Created uprising. Upon arrival, the weakened UNSC fleet was ambushed by four Banished dreadnoughts. The Banished had arrived at the ring earlier, and begun fortifying the ring's surface to neutralize Cortana.

Warmaster Atriox personally led Banished raiding parties aboard the Infinity in search of the Weapon, all the while sending occupation forces to the Ring's surface by the hundreds. Despite the UNSC repelling the boarders, the Infinity's main engine were taken offline within minutes after the initial attack, and Captain Lasky ordered the deployment of the Weapon to proceed with the mission to lock down Cortana. Under the overwhelming assault, Lasky ordered all hands aboard the Infinity to abandon ship.

John-117 ordered Fireteam Taurus to escort Lasky to a dropship while he held off the boarders at the hangar bay. However, despite his efforts, the hangar bay would eventually be lost to the Banished. As one dreadnought rammed the dorsal hull of the Infinity, causing massive structural damage, Atriox fought John-117 in the hangar bay and defeated the Spartan. The limp Spartan was thrown from the the hangar bay and into space.

After Lasky’s lifeboat was away, Spartan Hudson Griffin of Fireteam Taurus ordered the evacuation of the remaining Spartan-IVs. Spartan-IVs, marines, and crew fled onboard drop pods, Pelicans, and lifeboats to the surface of Installation 07, many being shot down seconds after exiting the vessel. Some were escorted by members of Fireteam Windfall onboard fighters.

In the region south of Silent Auditorium, the Banished set up three anti-air Gorespike cannons, which fired at numerous UNSC aircrafts landing at the area. This region became the most active battleground in the first 48 hours of the conflict. Recognizing the threat posed by the cannons, Spartan Hudson led Fireteam Taurus and made landfall in this region, where they fought through Banished patrols, with sniper support from Spartan Nina Kovan, to disable the three cannons. They succeed in disabling two cannons before a cataclysmic event on the ring - an explosion at the Silent Auditorium - disabled the third cannon.

In the end, the outcome of the space battle saw at least two Mulsanne-class frigates, including the, crashing on the fragmented section of the ring. The second frigate crashed between the three Gorespike cannons. Although the status of the UNSC Infinity is unknown aside from having suffered heavy damage from Banished vessels, she may have broke apart and crash landed on the ring.

Explosion on the Ring and Cortana's destruction
"Look around, Cortana. Your empire. Over! Your great plan? Ended at the hands of those who made you."

- Warmaster Atriox to Cortana as he presented her with the terms of her surrender following Created's defeat.

As UNSC forces scattered over the ring and fought against the Banished forces, Atriox confronted Cortana at the Silent Auditorium, claiming he had killed John-117 and Cortana's Created empire was over, leaving the latter devastated by the news of John-117's apparent death. Having consolidated her presence and core processes at the Silent Auditorium and seemingly locked down by the Weapon deployed from, Cortana realized her mistakes but could not retaliate. Atriox presented her with the terms of her surrender, intending to take control of the ring and access the secrets locked within the Silent Auditorium. In an attempt to prevent Atriox from accessing Silent Auditorium or activate the ring, Cortana initiated a local self-destruction sequence at the Auditorium, killing herself, fracturing the ring's surface, and leaving the installation inoperable for the Banished. Her efforts were proven to be temporary, as the ring soon begun its self-repair process, though it would take months to complete. Although he survived the explosion, Atriox was left severely scarred, and was also presumed dead by both the UNSC and the Banished. Cortana, in hopes of John-117's survival, predicted he would stop the Banished from accessing the Silent Auditorium and prevented the Weapon's deletion protocol so she could assist him, leaving the Weapon in the ring's subterranean structure for retrieval. At some point during the Installation 07 conflict, at least one Guardian Custode was present over Installation 07 and subsequently deactivated, crashing on the ring by 2560.

During the destruction event, Cortana also initiated an emergency translocation protocol, intending to disorient the Banished and stall their efforts. Installation 07, along with the debris from the space battle, was transported away from the the Ephsu system to an unknown location. The explosion also affected the ground battle between the UNSC and the Banished. The ring's fragmentation scattered UNSC ground forces, but disabled the third Gorespike cannon, allowing more UNSC aircrafts to land on the ring.

The UNSC scatters
"I wish I could tell you it was difficult... but it wasn't."

- Escharum to John-117.

Despite the explosion, the Banished occupied the ring, with some UNSC forces gathering on one of the fragments. The Banished committed a large force at the eastern fragmented sections of the ring. On one of the fragments to the west, a large group of survivors led by Spartan Hudson Griffin established a base of operations in the wreckage of the Mulsanne-class frigate, discovered by Spartan Vedrana Makovich. Under the leadership of Spartan Griffin, the UNSC forces at the Reverie conducted guerilla ops against the Banished forces. First Lieutenant Floyd conducted multiple field surveys and reconnaissance missions on nearby Banished outposts, reporting his findings to Spartans Griffin, Bertold Vettel, and Bonita Stone, while also attempting to contact other UNSC forces. The UNSC also set up multiple Forward Operating Bases in the regions on the fragmented section of the ring.

On January 20, 2560, Kovan conducted a recon sweep deep inside Banished-occupied territory. She observed that Banished forces were only unified under Escharum, with internal competition among its members. She reported her findings to Griffin, and suggested that an attempt on Banished War Chief Escharum's life may fragment the Banished leadership. Griffin decided their best course of action was to assassinate the War Chief. A four-Spartan team, the members of which were decided by drawing straws, was to infiltrate Banished territory and assassinate Escharum, while other Spartans remained at the Reverie to defend the base. In the end, on January 23, 2560, Spartan Griffin led Spartans Panago, Malik, and Sarkar on an assassination mission on Escharum. Griffin left Bertold Vettel in charge of the UNSC forces at the Reverie. However, Escharum anticipated Griffin's actions. His forces ambushed the Spartan team, killing the other three and leaving Griffin badly wounded. Escharum taunted Griffin, letting him know that he'd sent most of his forces to assault the Reverie. Griffin managed to send an encrypted message to warn Reverie before Escharum captured and handed him over to Chak 'Lok for torture. Under the combined leadership of Vettel and the counsel of Makovich, the UNSC forces at the Reverie braced for the Banished's attack.

On January 31, 2560, Chieftain Tremonius and Captain Arthoc led a massive Banished force from Riven Gate in an assault against the Reverie. Under an overwhelming assault, the UNSC forces retreated from the crash site on February 2. Following the battle, the crash site surrounding the ship was converted into a Banished outpost. As a reward for Tremonius' victory, Escharum had the outpost named after Tremonius, who would be promoted to the rank of Warlord.

At some point after the ring's fragmentation, the 511th Infantry Division established a base of operations in a canyon and are surveying that fragment. While fighting off Sentinel patrols and Banished talons, they were attempting to make contact with UNSC forces in comms range.

Banished occupation
"The hour approaches. Soon the Banished will stand victorious. Atriox... hear these words. Even from beyond this life, your will is served. Your forces occupy the ring, Within hours, it will be under our control. Humanity will cower before your legacy. They will burn. Their brazen defiance will be all but a memory."

- Escharum addressing Atriox and his will, heard by then celebrating Banished forces.

The surviving UNSC personnel were forced to conduct mostly defensive tactics over the next few months, losing their last Forward Operating Base by March 3. Meanwhile, the Banished began setting up more infrastructure on the ring. They built sensory arrays at the Horn of Abolition and hijacked a Forerunner resonance amplifier to boost their relays, thus always staying one step ahead of the UNSC forces. They also established Annex Ridge, where they conducted research on the ring's artifacts. Escharum ordered his Banished forces to capture UNSC survivors, who would be processed at Redoubt of Sundering before being taken to Chak 'Lok's Tower for interrogation under torture and duress, and then finally to Escharum's base, House of Reckoning. The UNSC forces were unable to stage any major offensives due to the loss of an organized leadership, but what Spartans remained enacted the Rubicon Protocol: doing all they could to prevent the Banished from taking control of the ring and protect Earth. In one particular incident, Spartans M. Jaide and Rosado managed to hijack a Barukaza Workshop siege-hauler carrying artifacts from Annex Ridge.

With little UNSC resistance, the Banished shifted their attention to excavations, salvaging UNSC hardware to aid their excavation efforts, while meeting resistance from the ring's self-repair process. By April 23, the Banished has found numerous cylixes buried in the ring. Tremonius found one such cylix, which contained the Xalanyn known as "the Harbinger". Under the supervision of Escharum, the Banished forced a human prisoner, Lucas Browning, to interface with the Harbinger's cylix, releasing her from stasis.

After her release, the Harbinger told Escharum of the Reformation, which would expedite the ring's self-repair process by creating materials for repairs. The process would return the ring to an operational status for Escharum, who hopes to achieve Atriox's goal of controlling the ring and claim the ring as their new home. However, unbeknownst to Escharum, the Harbinger seeks to rebuild the Silent Auditorium, which was destroyed when Cortana detonated the ring, and locate her fellow Xalanyn. Despite Escharum being distrustful towards the Harbinger, the two formed an uneasy alliance, bolstering the Banished forces with the Harbinger's Skimmers.

The Harbinger aided in the excavation efforts, personally inspecting excavation sites and modifying the Banished's mining equipment to cut through Forerunner alloys. Furthermore, upon the discovery of the Conservatory, where the monitor of the installation, 117649 Despondent Pyre, resided, they prioritized on excavating the facility. The Harbinger aimed to acquire the monitor's encephalon, which would allow her to initiate the Reformation. Having observed the excavation site, Spartans Makovich and Theodore Sorel correctly deduced that Escharum was searching for the Monitor. Over the next three weeks, the two stalled the Banished's excavation efforts by sabotaging the excavation machinery and disrupting supply lines. On May 14, with the help of Submonitor Adjutant Veridity, UNSC survivors led by Nina Kovan successfully managed to broadcast the ring's location into space using a beacon tower, hoping to draw UNSC reinforcements to Zeta Halo. Despite Makovich and Sorel's sabotage efforts, the Banished completed the excavation by May 15. Makovich and Sorel followed the Banished into the underground facility, but they were ambushed and killed by members of the Hand of Atriox. However, the Harbinger and the Banished would not find 117649 Despondent Pyre inside the Conservatory until the Master Chief's return.

The Master Chief returns
"The Master Chief has returned. This should anger me but strangely it does not. It invigorates me. Gives me new purpose. What use a War Chief with no war left to win? I could not have wished for a more worthy adversary. Atriox, I now understand why you did not kill him on the human craft. You wanted him to witness your victory. I will complete your work. Your vision."

- Escharum upon learning of John-117's survival.

On circa May 28, civilian engineer Fernando Esparza, onboard the Pelican Echo 216 he had stolen from Infinity six months prior, found John-117 drifting in space around Installation 07. The Spartan's armor had activated survival mode to keep the Spartan alive. After bringing him aboard and reactivating the armor via a power transfer, John-117 was awakened. Echo 216 was quickly discovered by the Banished dreadnought Ghost of Gbraakon, which activated its stasis beam to pull the Pelican onboard. John-117 left the Pelican and boarded the Gbraakon, destroying the ship to prevent the Pelican from being captured. Escharum was made aware of the Spartan's survival, and reacted with excitement.

After the destruction of the Gbraakon, John-117 was contacted by the Weapon, who had been stranded in the ring for the last six months. Esparza, piloting Echo 216, took the Spartan to a subterranean structure at the fragmented section of the ring, where the Spartan retrieved the Weapon. While returning to Outpost Tremonius at the surface, John-117 encountered and defeated Warlord Tremonius, thus returning the wreckage of Reverie to UNSC control.

Escharum ordered Chak 'Lok to lure the Master Chief to the Tower using Griffin's distress signal. At the Weapon's advice, John-117 pursued the signal to the Tower, where he confronted and killed 'Lok. Despite being freed from the torture device, Griffin succumbed to his wounds, but told John-117 of the Conservatory. John-117 and the Weapon then traveled to the excavation site, where the Spartan defeated Bassus, and entered the Conservatory. Inside the Conservatory, they watched 117649 Despondent Pyre being captured by Skimmers. Pyre was tortured and interrogated by the Harbinger, who retrieved the monitor's encephalon. With Pyre seemingly destroyed, submonitor Adjutant Resolution was activated. The Harbinger left for the surface, with John-117 in pursuit. At the entrance of the Conservatory, John-117 confronted the Harbinger, but was unable to prevent her from activating the Reformation using Pyre's encephalon. 43 Reformation Spires, including one Command Spire, began appearing at various locations on the ring, awaiting an initiation sequence. The Harbinger escaped, with the Spartan heading to the Reformation Spire that materialized outside the Conservatory.

Preventing the Reformation
John-117 fought through Banished defenses, including a pair of Mgalekgolo, at the base of the Reformation Spire, and entered the structure. Inside, the Spartan and the Weapon met Adjutant Resolution, who told them of the Spire's purpose: to rebuild the ring. John-117 ordered the Weapon to shut down the Reformation Spire to prevent the ring from being made operable. Adjutant Resolution attempted to intervene, leading to a short battle at Spire's observation platform, with John-117 defeating the submonitor in its armored chassis. The Weapon took the Spire offline, and they escaped the collapsing tower onboard Echo 216, with the Command Spire as their next objective.

However, while en route to the Command Spire, Echo 216 crash landed at the job the region south of the Silent Auditorium, having sustained damage from anti-air fire from the three Gorespike cannons, which had been reactivated. John-117 proceeded to the three cannons, eliminating the Banished defenses and destroying each cannon with the help of the Weapon. Escharum ordered the deployment of Hand of Atriox, with Tovarus and Hyperius attempting an intercept on John-117. They failed to deter the Spartan's progress, being killed by John-117. The Harbinger, anticipating the Chief's intent to shut down the Reformation, had Escharum set up defenses at the Command Spire, while she modified the data sequence for accessing the Spire. Intending to challenge the Master Chief in a duel, Escharum ordered Jega 'Rdomnai to capture the Spartan.

With the Harbinger modifying the sequence, John-117 and the Weapon arrived at the Command Spire to find its entrance under lockdown. They fought through Banished defenses to access four Forerunner beacons nearby, where the Weapon reconstructed a pure version of the sequence to access the Spire. The Harbinger, having realized that there is something guiding the Master Chief, scanned the Weapon and confirmed her existence while the Weapon was accessing the data strands beneath the Forerunner beacons. John-117 and the Weapon returned to the Command Spire, first passing through the Nexus located at the base of the Spire. The Banished troops inside, despite being reinforced by Sentinel Aggressors that were in support of initiating the Reformation, failed to fend off the Spartan, and John-117 uploaded the Weapon into the Nexus to activate the gravity lift to access the Spire. While the Weapon was in the system, the Harbinger hijacked the Weapon's routines, which, when paired with Despondent Pyre's encephalon, would correctly initialize the Reformation. However, the Weapon infiltrated the systems and retrieved Pyre's encephalon, that would allow her to halt the Reformation. John-117 and the Weapon entered the Command Spire, where they defeated the Banished and Sentinel defenses, including Adjutant Resolution, then shut down the Reformation. However, the Silent Auditorium was already partially rebuilt, and Escharum asked the Harbinger if that would be sufficient to carry out her plans, but she was unsure.

Test of legends
"Our battle ends here. Bear witness! Our story will become legend. Told by those that survive you."

- Escharum to John-117 as he prepare to fight John-117.

When Fernando Esparza flew Echo 216 towards the crumbling Command Spire to pick up John-117, Jega 'Rdomnai revealed himself in the cockpit, having boarded the Pelican at some point. The Sangheili took Esparza hostage, using the pilot as a bait to lure John-117 into a confrontation with Escharum. To escape the crumbling Spire, John-117 entered a portal activated by the Weapon. They were transported to the Repository, where they fought through Banished troops and Sentinels to the surface, and, from there, they stormed the House of Reckoning, destroying the Banished defenses along the way. Inside, Escharum had John-117 fight through multiple waves of Banished troops in two arenas constructed from UNSC ordnance and buildings. John-117 fought Jega 'Rdomnai in a duel, emerging victorious and finally confronting Escharum at the chamber where Esparza was held. Escharum protected himself with a shielding system which redirected gunfire to the gravity wells holding Esparza. The Weapon helped John-117 locate and destroy the relay transmitters supporting the shielding system, allowing the Spartan to breach the shields and take down Escharum. In his final moments, Escharum assured John-117 that his death will only inspire further conflict. However, after Escharum's death, Atriox would make his survival known, giving the Banished a newfound resolve and confidence to fight for the control of the ring. With Esparza rescued, the trio recovered Echo 216 and Esparza flew John-117 to the Silent Auditorium to stop the Harbinger.

Although the Banished set up defenses at the Silent Auditorium to protect the Harbinger, John-117 breached the main chamber with the help of Adjutant Resolution. The Spartan fought through the Banished forces defending the Harbinger, and the Harbinger herself as she interfaced with the transmitters in the main chamber to locate members of her species, the Endless. Despite the Weapon's attempt to intervene with the transmission, and John-117 defeating the Harbinger in battle, the Harbinger claimed her people have been found, and that they would be unleashed. The Auditorium began to collapse, but a portal suddenly appeared, allowing the two to escape. On the other side of the portal, they found themselves having traveled three days into the future. They were extracted by Echo 216, and taken to Outpost Tremonius with the intention of finishing the fight.

The battle continues
In the following days John-117, with the assistance of both Esparza and the Weapon, carried out anti-Banished operations and UNSC rescue missions. He managed to destroy eight Banished outposts, recapture eleven more FOBs, rescue twenty-five Marine squads and kill fourteen high-ranking members of the Banished plus the leader of a Gasgira patrol group known as Skimmer Alpha. Meanwhile Atriox, having survived the destruction of the Auditorium, discovered the whereabouts of the Endless and, after one hundred thousand years of imprisonment, finally released them. Atriox's sudden return gave to the Banished a newfound resolve and confidence.

December 12, 2559

 * A Banished fleet led by Atriox arrived at Installation 07 and began building fortifications on the ring.
 * A fleet of UNSC vessels led by the is ambushed by Banished forces over Installation 07. Captain Lasky orders all hands to abandon ship.
 * John-117 engages Atriox in a hangar onboard the Infinity and is thrown into space. The ship is presumed destroyed.
 * The surviving Infinity crew make landfall on the Ring. Fireteam Taurus and Spartan Nina Kovan disable two Banished Gorespike cannons in an area south of the Silent Auditorium.

December 13, 2559

 * In an effort to stop the Banished from taking control of the ring, Cortana detonates an explosion from the Silent Auditorium, fragmenting Installation 07 and killing herself and apparently Atriox in the process. Various UNSC survivors on the Ring's surface attempt to escape the destruction. Cortana's explosion unwittingly levelled the playing field in the fragmented section of the ring by taking out one of the Banished Gorespike cannons.
 * During the destruction event, Cortana initiated an emergency translocation protocol. Installation 07, along with the debris from the space battle, were transported away from the Ephsu system to an unknown location.

December 15, 2559

 * Spartan Makovich discovers the crash site of the and determines it to be a viable location for the UNSC's base of operations.

January 20, 2560

 * Spartan Nina Kovan scouts the Banished deep within the red zone, discovering a potential vulnerability of the enemy in that infighting is encouraged. Only Escharum's leadership keeps them in check.

January 23, 2560

 * Spartan Griffin organizes a mission to assassinate Escharum via a four-man team led by himself. He leaves Spartan Vettel in charge of the forces at the Reverie.

January 30, 2560

 * Spartan Griffin's team is ambushed by Escharum and all are killed except for him. Escharum informs him of his team's demise and of the Banished's impending assault on the Mortal Reverie. Griffin is able to send out an encoded message, warning the other UNSC survivors and telling them to abandon the vessel.
 * The survivors at the Reverie are only able to receive part of Griffin's transmission and, having not heard his order to flee, dig in for an assault by the Banished.

January 31, 2560

 * Banished Jiralhanae Chieftain Tremonius and Captain Arthoc gathers a massive Banished assault force at Riven Gate. Spartan Stone and Boulder Squad conduct a recon sweep at Riven Gate. Stone reports her findings to Mortal Reverie, and warns the Reverie that the Banished would arrive by nightfall.
 * The UNSC survivors at the Mortal Reverie prepare for the Banished assault. Spartans Makovich and Vettel discuss the UNSC's inability to win the upcoming battle and their dwindling options for the future.

February 2, 2560

 * Spartan Vettel orders the UNSC survivors to retreat from the Reverie under the Banished assault. The Banished converts the crash site into a Banished outpost.

March 3, 2560

 * Unofficial squads such as the Gravediggers and Hatetriox have been taking out Banished supply runners, raiding parties, towers, bridges and other Banished structures.
 * The UNSC loses all of its remaining Forward Operating Bases on the fragmented section of the ring.
 * Spartans Makovich, Stone, Vettel, and Sorel regroup with some UNSC survivors.

April 18, 2560

 * Using Lucas Browning as a Reclaimer, the Banished release the Harbinger from her cylix.

April 23, 2560

 * Spartan Stone recons Outpost Tremonius and sends a transmission to Makovich and Sorel that the Banished are sending forces to another excavation site.

April 24, 2560

 * Spartans Makovich and Sorel observe Banished activity around the Conservatory and realize the Banished are looking for Installation 07's monitor.

April 26, 2560

 * Spartan Stone, having made it into the Ring's subsurface infrastructure, finds the Cylixes holding the Xalanyn. She picks up a UNSC signal deeper inside the Ring and follows it. She is discovered by Banished forces and subsequently killed by Blademaster Jega 'Rdomnai.

April 29, 2560

 * Spartan Vettel sends out a signal to any remaining UNSC transmitters that he intends to assault Chak Lok's fortress and rescue Spartan Griffin.

May 9, 2560

 * Monitor 117649 Despondent Pyre is freed from her cradle by Spartan Tomas Horvath after having been locked away by Cortana prior to her destruction.
 * After learning of the Harbinger's release, Despondent Pyre provides Horvath, Nina Kovan, TJ Murphy, Isaiah Cameron, Erik Bender and Robin Dimik with a data key that will allow them to broadcast a superluminal message into human-occupied space with Zeta Halo's current galactic coordinates and the site's pertinent information.

May 14, 2560

 * UNSC survivors led by Spartan Nina Kovan take control of one of the ring's beacon towers and use it to broadcast Zeta Halo's new coordinates to UNSC space in the hopes of summoning reinforcements.
 * TJ Murphy, Isaiah Cameron and Gorian are all killed in the battle while Spartan Tomas Horvath is teleported to a far away location on the ring by a translocation pad just before it is destroyed by Banished fire.
 * The surviving UNSC forces are rescued by Submonitor 091 Adjutant Veridity and regroup.

May 15, 2560

 * Spartans Makovich and Sorel follow the Banished into the Conservatory with the intent to stop them from finding the monitor.
 * Inside the Conservatory, the two Spartans encounter Jega 'Rdomnai. Makovich stays behind to face off against the Sangheili and tells Sorel to go on without her. She is killed by 'Rdomnai.
 * The wounded Sorel encounters a Banished force led by Hyperius and Tovarus. He manages to take out many Banished before being slain.

May 26, 2560

 * Far from any surviving UNSC personnel, Spartan Horvath makes a final transmission on UNSC channels that he is heading up-spin beyond the reach of the Banished to look for survivors and Fireteam Intrepid. Having had no contact with any UNSC personnel, he makes an open plea to the Master Chief that they need him now more than ever.

Circa May 28, 2560
Around 6 months after the Battle over Installation 07 on December 12–13, 2559 Around 3 days after the Harbinger's demise and the subsquent collapse of the Silent Auditorium
 * John-117 is recovered from the remnants of the battle between the UNSC Infinity and the Banished by Echo 216 and its pilot, Fernando Esparza.
 * The Ghost of Gbraakon discovers Echo 216 and uses its stasis beam to pull the Pelican aboard. John-117 leaves the Pelican and boards the Gbraakon, overloading its engines, destroying the ship. Escharum is made aware of John-117's survival.
 * John-117 recovers the Weapon underneath the surface of Installation 07 and defeats Tremonius. Outpost Tremonius returns to UNSC control.
 * Under the command of Escharum, Chak 'Lok activates Spartan Griffin's distress signal to lure John-117 to his Tower. John-117 defeats Chak 'Lok inside his Tower and learns of a Banished mining operation into the Conservatory thanks to Spartan Griffin, who dies of his torture.
 * The Weapon helps John-117 defeat Bassus at the Excavation Site and shut down the drill preventing entry into the Conservatory.
 * The Weapon learns of a mysterious entity worse than the Flood recovered from a past exchange between Cortana and 117649 Despondent Pyre prior to the arrival of the UNSC Infinity.
 * John-117 meets the Harbinger, whose plans are to free the Endless from the Cylixes.
 * John-117 and the Weapon learn that the Harbinger and the Banished are planning to repair Installation 07 through Reformation Spires.
 * Echo 216 gets shot down by 3 Banished AA cannons en route to the Command Spire.
 * John-117 disables the AA cannons and defeats both Hyperius and Tovarus.
 * The Harbinger springs a trap on the Weapon while extracting the data needed to enter the Command Spire.
 * While exploring the Command Spire, more of Cortana's past actions are revealed, including her role in the destruction of Laconia Station at the hands of the AI Leonidas.
 * John-117 shuts downs all of the Spires, but Esparza is captured by Jega 'Rdomnai.
 * En route to the Pilot's rescue, the Weapon discovers that Cortana destroyed Doisac because Atriox refused to join the Created.
 * John-117 survives the House of Reckoning, kills Jega 'Rdomnai and Escharum and rescues the Pilot.
 * John-117 and the Weapon discover the true purpose of the Silent Auditorium, the site of Cortana's sacrifice, and defeats the Harbinger. However, the Harbinger succeeds in discovering the location of her people and transmitting it to an unknown recipient.
 * Echo 216 picks up John-117 and the Weapon from another location within Installation 07. Atriox discovers the Endless in their Cylixes.

Units

 * UNSC Navy
 * Blue Team
 * Spartan Operations
 * Fireteam Intrepid
 * Fireteam Shadow
 * Fireteam Taurus
 * Fireteam Windfall
 * UNSC Marine Corps
 * Barracuda Squad
 * Bengal Squad
 * Bluebell Squad
 * Boulder Squad
 * Boxer Squad
 * Carrera Squad
 * Cayman Squad
 * Cobra Squad
 * Courier Squad
 * Fortune Squad
 * Foxhound Squad
 * Harpoon Squad
 * Helix Squad
 * Indiana Squad
 * Jester Squad
 * Lancer Squad
 * Merchant Squad
 * Paladin Squad
 * Pronto Squad
 * Pyramid Squad
 * Riddle Squad
 * Starlight Squad
 * Thunder Squad
 * Titan Squad
 * Vantage Squad
 * Unknown
 * Boat crew
 * Gravediggers
 * Hatetriox
 * 511th Infantry Division

Units

 * Legions
 * Legion of the Corpse-Moon
 * Clan of the Ravaged Tusks
 * Clans and crews
 * Lance of the Writhing Star
 * Exodus Guard
 * Bulwark of Bone
 * Warial's Wrath
 * Brother's of Undending Ire
 * Heart of Tala
 * Beholders of the One Vapor
 * Sclera of Chu'ot
 * Thieves of the Claw
 * Hordeworms of Svir
 * Warriors of Malaston
 * Valorguards of the Chosen
 * Bloodbrave Guardians of Suban
 * Kaepra's Grief
 * Witch's Eye
 * Other units
 * Bloodstars

List of appearances

 * Become
 * Carry On
 * Forever We Fight
 * Halo Infinite
 * Halo: The Rubicon Protocol
 * Halo: Outcasts