Halo Universe

The Halo universe is a fictional setting for the video games Halo: Combat Evolved, Halo 2, the future games Halo 3 and Halo Wars, and the books listed on Halo (video game series).

United Nations Space Command
This is the main military defense branch of the Halo universe's United Nations, a world government evolved from the modern day UN. It has been decimated by the Covenant.

UNSC Planets and Locations
Originally colonized for its rich titanium deposits, Reach had mines throughout it running thousands of meters deep. UNSC High Command, Fleet Command and the Marine Corps had headquarters on Reach, as well as many primary Office of Naval Intelligence bases, which include CASTLE Base. CASTLE base was located on Reach underneath the Menachite Mountain range. This facility is where the Spartans first began their training. The facility was destroyed after the planet's fall to the Covenant in October 2552. A secret area beneath Reach's surface contained a Forerunner artifact that was highly desired by the Covenant. The fact that this artifact was so valuable to them is perhaps the main reason anyone survived Reach at all, because the Covenant were fearful of destroying it and did not target a large area around the mountain range when they glassed the planet and wiped out the rest of its inhabitants.
 * Earth - Humanity's homeworld, heavily fortified with 300 Super MAC Platforms and having the second of the two United Nations Space Command Headquarters. Africa seems to come out of it's poverty slum as indicated by the City of New Mombasa but no other locations and their conditions are given. Earth is being invaded and occupied by Covenant forces during the ending of Halo 2 and during Halo 3.
 * New Mombasa, East African Protectorate - The first city attacked when the Covenant invaded Earth in 2552. The Ark, a Forerunner structure that commands the Halos, is rumored to be located just outside of New Mombasa, somewhere between the city and Mount Kilimanjaro. In the final story in the Halo Graphic Novel, "Second Sunrise over New Mombasa", a journalist and several Marines overhear a conversation between two Elites, one of whom confirms that the Ark is present at New Mombasa's location and that they must clear the area to secure it.
 * The Ark - Located in the vicinity of New Mombasa, this structure is buried deep underground and is indicated to be a mechanism to activate the Halo network.
 * Sydney - This population centre features a military base as in Halo: First Strike
 * Reach - The planet Reach was the strategic and military HQ for the human United Nations Space Command. Located in the Epsilon Eridani star system, Reach was the biggest spaceport after Earth and served as the main fortress of defense during the 27 year Human-Covenant war. It was "glassed" by the Covenant in the novel Halo: The Fall of Reach and was briefly seen in flashback at the start of Halo 2.

The Covenant discovered the location of Reach after the Battle of Sigma Octanus IV. Using a diversionary attack, they ensured human ships would scan for survivors after the battle then attached a spy Drone onto the UNSC ship Iroquois. This drone took images of star constellations for several days before returning to a waiting ship by Slipspace, telling to the Covenant every place the human ship had been. They presumably scouted every system before finding Reach.

Reach was defended by more than a hundred UNSC ships, including the Hannibal], [[Pillar of Autumn, and the supercarrier Trafalgar. In addition to the fleet, Reach was defended by 20 Mark V Orbital Magnetic Accelerator Canon satellites (called SMAC, or Super MAC guns, and capable of propelling a round at 40% of lightspeed using superconducting magnets). Though the defenses were enormous, they couldn't hold back the Covenant onslaught, which was prepared to sacrifice a single ship for the destruction of a MAC gun. The human fleet was decimated and its ground forces obliterated by the Covenant - the remaining ships, including the Pillar of Autumn, were forced to jump out of the system. After the Forerunner artifact on the surface was located, the Covenant "set fire" to Reach by "glassing" the planet with plasma. This presumably killed all remaining humans on the planet and scorched it to the point of being uninhabitable, save for the tiny section in which the search for artifacts continued.

After the events at Halo, the Master Chief returned to Reach on the captured Covenant flagship Ascendant Justice to search for any survivors of the Spartan team he sent down to defend the surface. Several Spartans had survived, along with a member of Reach's high command, Vice Admiral Danforth Whitcomb, and Dr. Halsey, the head of the Spartan project and a major human scientist. During the novel, Halo: First Strike, the survivors of Reach returned to the small section of the surface that was not destroyed and recovered a Forerunner artifact that was buried deep in the surface. Several more Covenant ships were destroyed by the AI Cortana aboard Ascendant Justice, and the survivors escaped Reach to [[Slipspace].

Several experimental nuclear bombs (codenamed Novas, and featuring a lithium triteride casing that would boost the yield a hundredfold) were in development on Reach at the time of the Covenant attack. Vice Admiral Whitcomb rigged the bombs to explode ten days after the initial invasion, hoping that the Covenant would either take the bombs back to their homeworld for study or that when they exploded, the Novas would take out their foes on Reach. Due to the fact that just ten hours was left on the countdown when the Admiral and other survivors escaped,Covenant Engineers deactivated the bombs, placing them in the storage bay of a Covenant supercarrier. Through a freak accident and more tampering of the engineers, at least one of the NOVA bombs detonated destroying a full Covenant battle group, a medium sized moon, and causing complete devastation of a near by Covenant held planet.


 * ONI Castle Base - Located on Reach, is the headquarters of Office of Naval Intelligence operations. A crystal of unusual characteristics with the ability to affect not only gravity, but space time is found in an ancient Forerunner cave buried deep underneath the Castle Base.


 * Jericho VII - The location of the battle at the beginning of the Fall of Reach, an Inner Colony, destroyed by the Covenant at the beginning of 2535. A large number of orphans from this planet enlist for the SPARTAN-III project.
 * Paris IV - Site of a major battle between the UNSC and Covenant forces; Sergeant Major A.J. Johnson is a veteran of the battle, where he supposedly contracted Boren's Syndrome, making him immune to Flood infestation.
 * Eridanus II – Eridanus II was the home planet of the SPARTAN II supersoldier Master Chief John-117.
 * Harvest – A human outer colony] "farm" planet, first target of the [[Covenant and glassed by them in 2525. A large number of orphans from this planet enlist for the SPARTAN-III program.
 * Sigma Octanus IV — A colony planet in the Halo series, significant because Installation 04's "coordinates" were discovered there on a shard of ancient rock. The planet is home to several million humans. It was also the location of two historic victories over the Covenant fleet. The first was a minor battle in which Commander Jacob Keyes destroyed three enemy warships causing the forth to retreat. The next, larger fleet scale battle, was considered the biggest human victory since Admiral Cole retook Harvest. Its capital city is called Cote D'Azur, and was destroyed by a SPARTAN-II team using a Havok nuclear mine after being overrun with Covenant ground forces.
 * Coral - An inner colony which is glassed by the Covenant during the I Love Bees plot line. Formerly the site of a UNSC/ONI] archaeological dig that uncovered a [[Forerunner structure. Coral's canon-status is in question along with the rest of the Haunted Apiary ARG.
 * Troy - A colony which had prior warning from an ONI Corvette, of an impending attack by the Covenant. Evacuation was slow and had barely begun when the attack occurred and the evacuation was covered up by ONI and the UNSC to prevent hostilities rising from the civilian populace against the UNSC.
 * Draco III - A world attacked by the Covenant sometime before the events of Sigma Octanus IV. Because they couldn't reach the location in time, the SPARTAN-II's watched via satellite as Covenant Grunts and Jackals slaughtered a group of survivors.

The Covenant
A theocratic hegemony comprising many species of aliens led by a caste of religious leaders known as "Prophets." Engaged in a 27-year war with humanity and currently embroiled in a genocidal civil war, they serve as the initial and primary antagonists throughout Halo: Combat Evolved, Halo 2, and other Halo media.

Covenant Locations

 * High Charity - A giant station/city that serves as the capital of the Covenant alliance and the home of its theocratic leaders the Prophet Hierarchs. It exists as a massive mobile space station with a dome-shaped surface. Inside it harbors an entire city powered by a Forerunner ship touching the roof of the station in the center of it. It can travel through slipspace like any other Covenant ship. As of the end of Halo 2, Flood have hijacked a human ship (In Amber Clad) and infested High Charity, and the Forerunner ship has separated itself.


 * Joyous Exultation - A Covenant-held world that was severely damaged by Admiral Whitcomb's NOVA Bomb during the events of Halo: Ghosts of Onyx.

The Forerunners
An ancient, technologically advanced and mysterious race that died out millennia ago after an extended period of war with the Flood. In desperation, the Forerunners activated the Halo rings, thus killing them and all other potential food sources for the Flood. They built the Halos and many other artifacts and structures throughout the galaxy.

Forerunner locations

 * Threshold - The gas giant Installation 04 (or Alpha Halo) orbited before its destruction in the events of Halo: Combat Evolved. There is a multiplayer map set on its moon Basis, and two campaign levels set on a gas mine in Threshold's low orbit.


 * Substance - The gas giant Installation 05 (Delta Halo) orbits.


 * Halos - Titanic ring-shaped constructs that serve as weapons of last resort to contain the Flood. Has the power to erase all life in the galaxy.
 * Onyx - Artificial "shield world" constructed by the Forerunners, formed from literally trillions of Sentinels interlocked into a planetary body. Served as the training ground for the SPARTAN-III program. At the core of the planet is a Slipspace rift that connects to a compressed Dyson Sphere isolated from normal space-time, which serves as a bomb shelter against the activation of the Halos.

The Flood
A virulent, parasitic alien race that absorbs individuals with sufficient mass and intelligence as part of itself. The Flood appears to be a hive or communal mind, possibly under one leader (such as Gravemind). The Flood spores mutate the host's body into a combat form, which if sustaining sufficient damage becomes a carrier form, an incubator for more spores. The Flood is considered a parasite and dangerous enemy by both the Covenant and UNSC.

Travel

 * Slipspace is the primary method of faster than light travel in the Halo universe. A Forerunner crystal captured at Reach allowed for manipulation of space-time and Slipspace, dramatically shortening the length of travel time through Slipspace.
 * The space elevators in New Mombasa and Cuba, among others, are used to transport goods and people from Earth's surface to space quickly and efficiently.
 * Wheeled vehicles similar in appearance to today's vehicles are used as the main mode of civilian transport on Earth's surface, as seen in Halo 2.

Early Conflicts
In the years 2160-2200, various governments, and factions fought for control of Earth and its first Colonies. As overpopulation and unrest on Earth mounted, new political movements formed including the Jovian Frieden and Koslovics led by Vladimir Koslov, resurgences of Fascism and Neo Communism which waged the Interplanetary, Rain Forest Wars Campaign and Mars clashes and were defeated by the United Nations Space Command.

The Human Colonization of the Orion Arm
In the years 2170-2291, the United Nations Space Command (UNSC) successfully developed humanity's first faster than light drive, the Shaw-Fujikawa Translight Engine. For the first time in history, the rapid colonization of other worlds is made possible. By 2390, 210 worlds had been occupied by humans, and were being actively terraformed to suit man's needs. These worlds are to become known as the Inner Colonies. By 2490, the UNSC's fledging Interstellar Empire had expanded to between 800 to 1000 planets throughout the Orion Arm of the Milky Way Galaxy. During this period, the planet Reach becomes one of the two headquarters of the UNSC military and government (the other was Earth itself), and is destined to become the most heavily fortified world under human control and the Inner Colonies became the heart of the United Nations Imperial Government.

In addition, there were numerous small-scale brushfire wars in the Outer Colonies, which served to tax UNSC resources.

Rebellion/SPARTAN Project
At the time of 2517, The UNSC was facing extremely low morale due to piracy and the Brushfire Wars. In order to remove the rebellion without a significant sacrifice of human life, Dr. Catherine Halsey moves forward with the SPARTAN-II project. 75 gifted children were abducted and replaced by flash-clones, and drafted into the UNSC. The children went through rigorous training and physical augmentations. Code-named SPARTANs, these genetically enhanced troops were trained from the age of six into a life of battle, and would become a great asset against the Covenant.

On September 12, 2525 the Spartans were sent to the Eridanus II system to capture Colonel Robert Watts. The mission was successful, and therefore significantly reduced the pirate threat. However, the role of the SPARTANs did not end with the capture of Robert Watts, since they were needed for the new war against the Covenant.

Shortly after the capture of Colonel Robert Watts, the SPARTANs became part of the UNSC's military ground forces. Before engaging the Covenant, all SPARTANs were given special armor designated MJOLNIR battle armor, which, in layman’s terms, can increase their strength, speed, and reaction time. They were the only ones who could wear it, as those without the proper body training or biological augmentations killed themselves with strength-enhanced convulsions.

The Human-Covenant War begins
On February 3, 2525, an orbital platform near the UNSC colony of Harvest detected an unknown object on its long range radar. The object was constructed with materials unlike anything seen before. All contact with Harvest was lost soon after. The Colonial Military Administration sent the scout ship Argo to investigate. That ship arrived in-system on April 20, but other than a brief transmission to confirm it arrived in the system, no further reports were made. In response, UNSC Fleet Command assembled a battle group consisting of the destroyer Heracles as well as the frigates Arabia and Vostok. They entered the Harvest System on October 7 and discovered the once-lush planet to be completely incinerated and the surface melted down to glass. All three million inhabitants were presumed dead. The battlegroup soon then found the vessel responsible for the attack still orbiting the planet. The vessel, which was identified later as belonging to the alien alliance known as the Covenant then launched an immediate attack upon the three UNSC ships. Only one, the Heracles, managed to limp back to Reach, badly damaged. The Heracles returned with a message that was sent to them, pre-translated, saying, "Your destruction is the will of the gods, and we are their instrument".

In response, the UNSC was placed on full alert and on November 1; Vice Admiral Preston Cole mobilized the largest space fleet in human history to retake Harvest.

Vice Admiral Cole's war fleet defeated the Covenant ships at Harvest in 2531. The victory was celebrated and publicized on every colony all the way to Earth. The UNSC media however didn't mention that Cole had won only because he outnumbered the Covenant three to one, and even then, he had lost two-thirds of his fleet. Promoted to Admiral, Cole spent the next four years waging a costly campaign to defend the colonies from continued Covenant assault. However despite his excellent leadership and tactical brilliance, one by one the colony worlds fell. The highly advanced Covenant ships simply outclassed the UNSC vessels. Their energy shields and plasma weapons were vastly superior to UNSC chemical and projectile weaponry.

By 2535, virtually all of the Outer Colony worlds had been destroyed by the Covenant and the Inner Colonies were being invaded. The Cole Protocol was established by military order: all human vessels must ensure that Covenant forces do not find Earth. To achieve this whenever they must jump out of a battle, they must do so to a randomized vector that points away from any human worlds.

====The Battle of Reach==== By 2552, many of Humanity's Outer Colonies had been destroyed by the Covenant (although they were repulsed with significant losses at Sigma Octanus IV). In a move of desperation, the UNSC ordered a secret plan to capture a Covenant ship using a SPARTAN task force and find the coordinates of their home planet, as well as capturing one of the Covenant's leaders. A group of SPARTANs, led by the Master Chief, are chosen for this mission, and board a specially outfitted Halcyon-class cruiser, the Pillar of Autumn, under the command of Captain Jacob Keyes, as well as an upgrade to the MJOLNIR battle armor armor, completely integrated with an energy shielding system and AI interface. The Master Chief meets and is assigned Cortana, who is to serve as his team's hacker and Covenant technology specialist. This plan, however, was interrupted when the Covenant launched a surprise attack on the world of Reach, which they had deviously located via an automated probe attached to the hull of the UNSC destroyer Iroquois.

During this battle, most of Reach is overrun and glassed, and the Human fleet is obliterated, as the humans were outnumbered over three to one, giving them absolutely no chance, even with orbital MAC emplacements. Worse still, the Master Chief discovers that most of the remaining SPARTAN-IIs were most likely killed on the surface of the planet during its bombardment. The Master Chief, escapes with the Pillar of Autumn. In accordance with the Cole Protocol, the Autumn follows a "randomized" slipspace vector which leads to the discovery of the Halo installation. This vector is later revealed to have been quickly generated from some Forerunner hieroglyphs by Cortana.

First Strike
Occurs between the first and second Halo video games. The story starts off with Master Chief and a few other survivors in space above the destroyed Halo. They capture a Covenant flagship and make their way back to Reach. When they arrive they find the entire planet ravaged. Yet something is strange. The Covenant usually Glass a world and move on, but there are small patches of the planet left unscathed. In an alternate storyline we find out that other spartans have found an ancient Forerunner structure under ONI's Castle Base. There they find a special artifact that warps space time.

Cortana, now in control of the Covenant ship, docks with a partially destroyed UNSC ship and combines their power (and also to allow them to return to Earth without violating the Cole Protocol by bringing a potentially "bugged" Covenant ship with them). After toying around with the controls she realizes that the Covenant know virtually nothing about the technology they possess. She redesigns the Plasma cannons to fire more effectively, increasing their destructive power. She also finds out how the Covenant move so easily through Slipspace. The technology she gathers could effectively turn the tide of the war.

After going through many battles the Master Chief and other Spartans discover a massive plot to attack the Sol system (Earth). They covertly attack and destroy a massive Covenant refit and repair station along with an attack force many times larger than the one that attacked Reach. In doing so they lose the Covenant flagship; however, they save the UNSC ship and escape back to earth with it. Thus begins Halo 2.

Halo 2
The game starts with a Covenant attack on Earth. Master Chief begins on one of the three hundred space defense platforms which orbit the planet. After repelling the Covenant boarding parties, the battle shifts to Earth's surface.

The player engages in urban combat in the city of New Mombasa. After which a Covenant ship makes a slipspace jump which destroys the city, the UNSC ship the In Amber Clad, with the Master Chief aboard gets swept up in the warp field in a desperate effort to follow it.

The player is transported to the vicinity of another Halo ring - the Delta Halo - perhaps many tens of thousands of light years from Earth, on which they land. Also, a power struggle within the Covenant is revealed, with Brutes usurping the role of the Elites. Furthermore, there is a movement, regarded by the Covenant leadership as heretical, which argues that Covenant teachings aren't true. Lastly, we are introduced to an (apparently massive) creature called the Gravemind, which appears to be the controlling mind of the Flood. The creature is obviously highly intelligent and gives the impression of knowing a great deal. It appears to live deep within Delta Halo, out of sight and yet its actual size, although not revealed, may occupy many of the entire hidden underground caverns that encircle the ring.

At some point, when she does not want a remote detonation of In Amber Clad, Cortana becomes separated from the Master Chief and is left within a computer on High Charity.

The Halos, we learn from 343 Guilty Spark, were built to prevent the Flood from spreading throughout the Galaxy, and that the Forerunners who built it were wiped out when they fired it as a "weapon of last resort" at some point in the remote past. In spite of this, the Brute leader Tartarus activates the ring in preparation to fire, to bring about - in his eyes - the Great Journey. The player must fight to retrieve the Index and deactivate the ring before it fires and destroys all sentient life in the Galaxy.

The Index is retrieved and the Halo cannot fire. 343 Guilty Spark reveals that although the Index was removed before Delta Halo had time to complete it's firing sequence, it sent signals to other Halos in the Galaxy, putting them on standby mode. Now, they can be activated remotely from the Ark (assumed to be either on Earth or the Forerunner Ship itself). The game ends here and the credits roll.

After the credits roll a teaser for Halo 3 shows where the flood has completely taken over High Charity with with the gravemind saying "Silence fills the empty grave now that I am gone, but my mind is not at rest, for questions linger on." The scene then changes to a stand in the council chambers of the hierachs the Gravemind then says "now I shall ask, and you shall answer." It then changes to Cortana saying "Alright, shoot".

Halo: Ghosts of Onyx
The novel begins with a group of SPARTAN-IIIs belonging to Beta Company deploying to a Covenant fleet refueling depot on Pegasi Delta. They proceed to destroy the facility, but due to unexpectedly heavy Covenant resistance, all but two of the three hundred Spartan team is wiped out. The only survivors, Tom-B292 and Lucy-B091, are revealed to be only twelve years old, and Lucy is traumatized and rendered mute.

The novel then cuts to a raid by the SPARTAN-II Blue Team on a rebel base at planet Victoria to recover stolen nuclear warheads. The team is nearly captured by a rebel ambush, but is saved by the timely, intuitive intervention of Kurt-051. Shortly afterward, the novel cuts to a meeting between Colonel James Ackerson of Section Three of the Office of Naval Intelligence, and the top leadership of ONI. In this meeting, they agree that the SPARTAN-II program is prohibitively expensive and that a more streamlined, "disposable" breed of Spartans must be trained for high-risk operations. This becomes the SPARTAN-III program, in which young recruits are gathered from worlds destroyed by the Covenant and trained by the SPARTAN-IIs' original trainer, Chief Petty Officer Mendez. To assist in this endeavor, Ackerson forcibly recruits and fakes the death of Kurt-051, and promotes him to Lieutenant, Junior Grade, before placing him in command of the S-III program and granting him the surname of "Ambrose." The operation is based on a secret system named "Onyx," which is the site of a major archaeological survey also being conducted by ONI.

The first S-III company, Alpha Company, proves to be a startling success, but is wiped out when deployed to target a major Covenant shipyard in a mission codenamed Operation PROMETHEUS. Shaken by the images of the battle and massacre of his troops, Kurt proceeds to improve the training regimen for his next batch of recruits, only to watch them fall by the hundreds at Pegasi Delta during Operation TORPEDO. He then institutes an illegal medical procedure in the third group of S-IIIs, which will harden their minds and bodies against pain and shock to better allow them to survive.

On October 31, 2552, the top three teams of the S-III Gamma Company, Teams Saber, Katana, and Gladius, conduct a training exercise near a restricted area on the planet, only to find themselves and other UNSC personnel under attack by an unidentified class of alien drone, that are later identified as Sentinels. Very quickly, the few humans on the planet are either wiped out or struggling to survive against this new, unexpected threat.

At this point, Doctor Catherine Halsey and Kelly-087 arrive to investigate the mysterious planet, but are attacked by more of the Sentinels and crash land. Once on the planet, they meet up with the human survivors of the attacks, including S-III Team Saber, Kurt, and Chief Mendez. Halsey identifies the drones as Sentinels from the information she reviewed from SPARTAN-117's logs on Halo, and proceeds to call for reinforcements, piggybacking her transmission on, ironically, another transmission made by Cortana at the end of Halo 2, On the message she simply asks for the best the UNSC can put forth asking for the high Command to send Spartans.

The action switches to Earth, two weeks after the First Battle of Earth, where the planet is under siege by Covenant forces. UNSC and Covenant forces battle in space and on the ground, and Fred-104, Will-043, and Linda-058 are pulled out of the line of fire by Fleet Admiral Hood, who responds to Halsey's call for reinforcements by dispatching the Spartans to Onyx. Hijacking a Covenant destroyer called Bloodied Spirit, the Spartans head for Onyx, only to be caught in the middle of a battle between Brute and Elite ships on the way. Barely escaping, the Spartans arrive at Onyx and are shot down by more of the Sentinels. They crash land and link up with the other human survivors, and then make their way toward the restricted area of Onyx after shaking Sentinel pursuit.

Meanwhile, a Grunt named Kwassass is aboard a Covenant Fleet carrier named the Sublime Transcendence. The Engineers are busy checking out what turns out to be one of Vice Admiral Danforth Whitcomb's Nova bombs. Kwassass pulls out the box from the nuke, and is attacked by Huragok. The Engineers manage to put it back in and a clear transmission comes forth:

This is the prototype NOVA bomb, nine fusion warheads encased in lithium triterade armor. When detonated it compresses its fusion material to a neutron-star density, boosting the thermonuclear yield a hundredfold. I am Vice Admiral Danforth Whitcomb, temporarily in command of the UNSC military base Reach. To the Covenant uglies that might be listening, you have a few seconds to pray to your dammed [sic] heathen gods. You all have a nice day in hell.

While this is going on, the Sanghelli leader Xytan rallies the Elites together, and prepares to send them to Onyx. A battle group of eighteen destroyers, two cruisers and one carrier prepare to go to Onyx, and retrieve the Forerunner technology. A split-second after they jump to slipspace, the Nova goes off, destroying every ship not on the dark side of the planet Joyous Exultation. A quarter of the world is scorched, a moon destroyed, and three hundred-kilometer-per-hour winds obliterate cities.

A large Covenant fleet and a UNSC reinforcement fleet arrive at Onyx, where they encounter one another and the stubborn Sentinel defenders of the planet, which attack anything approaching the system. In the ensuing battle, the entire UNSC fleet is destroyed save for one prowler-class vessel, which stays hidden and observes events unfolding.

The human forces on Onyx discover an ancient Forerunner city, and are guided into a massive dome by Halsey, who determines that the entire planet is a "shield world" referred to by the Forerunners as The Sharpened Shield. Fighting off determined Covenant pursuers, they press on into the heart of the planet to find its secrets, but not before the ONI AI communicates to Doctor Halsey the importance of shutting down a Forerunner "factory located at the "tip" of the plant that churned out literally hundreds of thousands of drones every hour. Disabling the factory, they press on to the planet's core, where they discover a slipspace rift that shunts those that pass through it to a miniaturized Dyson Sphere that is separated from normal space-time by advanced Forerunner Slipspace technology. Will falls fighting off the Covenant, and Kurt remains behind to ensure that the Covenant do not plunder Onyx's secrets, giving his life to prevent them from reopening the rift.

From outside Onyx, the surviving UNSC prowler watches on as the planet's surface rips apart, to reveal that the entire world is constructed of literally trillions of Sentinels, all connected together to provide an impenetrable defense around the Dyson Sphere at the heart of the planet. Within this sphere, which features terrain similar to that of Earth, the surviving humans discover that the planet is literally a massive bomb shelter for the Forerunner to have survived the activation of the Halos, but find themselves alone in the vast habitat; for some reason, the Forerunner never entered this structure when the Halos were first activated.