Designate: Shadow Fox

Hundreds of years from now, Earth's fledgling planetary empire had been drawn into a merciless war with a consortium of alien races known as the Covenant. Covenant technology was far beyond that of Earth, and the humans were losing. Whole planets were being destroyed. Billions had died. It was only a matter of time before the Covenant found Earth, and destroyed it.

The most recent human planet to be discovered by the Covenant fleet was Reach, population 700 million. On the planet Reach, the colonies were in ruins from its destruction by the Covenant after an invasion. Noble Team, a Special Forces Spartan Team dispatched to discover why a communications relay had gone offline, discoverd Covenant forces on Reach. Soon after, the team defended "Sword Base", an Office of Naval Intelligence (ONI) installation, from a Covenant vessel. The team met Catherine Halsey, a scientist and the mastermind behind the Spartan program and their MJOLNIR powered armor. Halsey informed Noble Team that the Covenant forces at the relay were searching for important information.

Jun, the team's Marksman and Noble 4, and Noble Six, a Lieutenant new to the team, were dispatched on a covert mission to assess the Covenant's strength and discover an invasion force gathering on the planet. The following morning, Noble Team assisted U.N.S.C. forces in assaulting a Covenant ground base. When a massive Covenant super-carrier joined the fight, Jorge and Six took part in a plan to destroy the carrier using a makeshift bomb. The Spartans used starfighter Sabres to infiltrate a smaller Covenant corvette, prepare the bomb and set the corvette on a docking course with the carrier. The bomb's timer was damaged, and so Jorge stayed behind and sacrificed himself to destroy the carrier. Moments later, huge numbers of Covenant ships arrived at Reach and began a full-scale invasion.

Six returned to the surface and traveled to the city of New Alexandria. The Spartan aided the local military in fighting the Covenant and evacuating the city, reuniting with Noble Team along the way. They retreated to an underground bunker when the Covenant began to bombard the city with plasma, but Kat, Noble 2, was killed by a Covenant sniper before they reached it. Recalled to Sword Base, Noble Team was guided underground to an ancient artifact that Halsey believed was key to winning the war against the Covenant. Six, Noble Leader Carter, and Noble 3 Emile were entrusted with transporting the artificial intelligence Cortana, and the information she carried concerning the artifact, to the U.N.S.C. ship Pillar of Autumn. Jun left the team to escort Halsey to another base.

En route to the Autumn's dry dock, Carter was critically wounded piloting a Pelican dropship. He rammed his ship into a Covenant Scarab mobile assault platform, allowing Six and Emile to safely reach the shipyard. Emile used a mass driver emplacement to defend the Autumn while Six fought through Covenant ground forces to get Cortana to the Autumn's captain, Jacob Keyes. When Emile was slain by Elites, Six remained behind to control the gun, ensuring the Autumn's escape. The Autumn fled from Reach and discoverd the HALO ringworld.

After sustaining heavy damage, Six dropped his shattered helmet and was overwhelmed and killed. Years later, Six's helmet remained on the grassy plains of a then-restored Reach. Halsey eulogized Noble Team, who ultimately enabled humanity's victory over the Covenant.

The Covenant annihilated Reach utterly. As the Pillar of Autumn escaped the battle in a desperate attempt to lead the Covenant away from Earth, the ship charted a course for a distant unexplored system.

In a move that baffled the Commander and her crew, the entire Covenant fleet gave chase.

When the humans arrived at their destination, they found an alien artifact of enormous size in orbit between a gas giant and its moon. They had found HALO, a ring ten thousand kilometers in diameter, with a breathable atmosphere. On its inner surface, HALO had oceans, continents, varied climatic zones. It was esentially a habitat.

Pursued by Covenant warships to a massive and ancient ring construct deep in the void, the United Nations Space Command had improvised a guerilla war over land, sea and air, using the arsenals and vehicles of three distinct cultures. Using everything from composite swords to orbital bombardment, driving everything from giant tanks to agile combat aircraft, the U.N.S.C. waged intense warfare over and under the surface of the world.

The last surviving human ship from the fall of Reach, the Spirit of Fire, was sent to the ruined planet Harvest to investigate Covenant activity, where it's Captain, Captain Cutter, learned that the Covenant had excavated something at the planet's northern pole. When the U.N.S.C.'s main outpost on Harvest was captured, Cutter ordered Sergeant Forge to retake it. Soon after, Forge scouted a Covenant excavation and discovered that they, under the direction of the Arbiter, had discovered a Forerunner facility. Forge's troops defeated the Covenant forces before they could destroy the installation, and Professor Anders, a lead researcher aboard the Spirit, arrived. She determined that the facility was an interstellar map, and recognized a set of coordinates that pointed to the human colony of Arcadia.

After repelling a Covenant counterattack on the Forerunner facility, the Spirit of Fire traveled to Arcadia, where the Covenant had begun raiding local cities and slaughtering civilians. Forge contacted the local Spartan special forces, Spartan RED Team, and assisted with the evacuation process. The Covenant built a giant energy shield to hide the construction of a gigantic Scarab super-weapon on the planet, but the U.N.S.C. forces used experimental equipment, prototype-based Plasma Rhino mortars, to break through. The Scarab was destroyed, but the Arbiter kidnapped Anders while she was documenting among the wreckage and escaped the planet.

Forge and the Spartans returned to the Spirit of Fire and the crew followed Anders' signal to an uncharted planet in another star system. The planet's surface was infested by the parasitic Flood, an alien being that infected hosts and morphed them into grotesque drones, who attacked and assimilated any sentient life they encountered. The Spirit of Fire inadvertently activated a Forerunner docking station and entered the planet's interior. Flood boarded the ship, and very soon Forerunner Sentinels appeared to cleanse the Flood threat and also to destroy all U.N.S.C. forces in the process. The crew discovered the planet was actually hollow, with a habitable interior and a miniature sun. The Spirit of Fire escaped the enterior of the planet, and collided with a Covenant Corvette Warship. After breaking off from the warship and repairing the ship's reactor, the Spirit of Fire escaped, and discovered what the Covenant was up to. The Covenant's plan was to activate a dormant fleet of highly advanced Forerunner starships inside the planet using Anders to activate it, and use them to obliterate humanity.

While the Forerunner ships were being activated, Anders escaped through a teleportation device and was rescued by Sergeant Forge on the surface of the planet. Cutter decided to destroy the Forerunner fleet rather than allow the Covenant to use it. Anders formulated a plan to detonate the ship's faster-than-light drive in the planet's sun, as the explosion would cause a supernova, leaving nothing but dust. Before they could prepare the reactor, Forge and the Spartans were ambushed by the Arbiter and his Elites. The Spartans dispatched the aliens and Forge killed the Arbiter. The reactor was damaged during the fight, necessitating a manual detonation. Forge volunteered for the suicidal task, telling the Spartans that they would be needed in the coming fight. The Spirit of Fire escaped just as Forge overloaded the reactor, destroying the Forerunner fleet. Without its faster-than-light drive, the Spirit of Fire was left drifting in space.

That's when Shadow Fox came in.

Spartans Archer and Martyr, a Marksman Operator and a Demolition Engineer, were the Spartan team aboard the North Star, a U.N.S.C. warship. They were sent in to retrieve the Spirit of Fire, repair it with a new drive, and ally with it to destroy a Covenant threat. The Covenant had built a slip-space drive that would allow them to light-jump anywhere across the galaxies. Their job was to destroy it. That was when it all went haywire.

This is where their story begins.