Master Chief Petty Officer of the Navy, John-117 is a SPARTAN-II Commando of the UNSC Naval Special Warfare Command. With nearly 30 years of active duty, he is one of the most decorated soldiers in the United Nations Space Command and has earned every known medal in the UNSC except the Prisoner of War Medallion. In 2553, John-117 went missing in action after the Battle of Installation 00 when he and the current Arbiter Thel 'Vadam stopped (or slowed as the Gravemind had said) the Flood threat.
He is the focal character and playable in Halo: Combat Evolved, Halo 2, and Halo 3. In the actual Halo games, John is only ever referred to by name once, by Cortana, in the ending cutscene of Halo 3 before the credits. He is referred to universally by humans simply as the "Master Chief", "Chief" for short and "Sierra-117". The Covenant is aware of the power of the Spartans, and refer to the Master Chief as "the Demon". Meanwhile, John is referred to as "Reclaimer" by both 343 Guilty Spark and 2401 Penitent Tangent, although this seems to be a universal title given to all humans, rather than specifically referring to John-117.
Childhood and Spartan TrainingEdit
Born in about 2511, John lived with his mother and father in Elysium City, on the colony world Eridanus II. As a child, John had brown hair, freckles, and a small gap between his front teeth. In a memory, John recalled that his mother was "kind and smelled of soap." At the age of six, he was identified by Dr. Halsey as one of 150 preliminary candidates for the SPARTAN-II Program. John was an ideal physical and mental candidate, standing a head taller than the majority of his schoolmates, having greater physical proportions, possessing strength, exhibiting reflexes, and having an aggressive drive for success. When Dr. Halsey and Lieutenant Jacob Keyes visited Eridanus II in 2517 to study him, they were impressed with his intellect and luck. In a final test of his viability as a candidate, he was asked to determine which side an old coin would land on. He watched the coin as it flew in the air and caught it before it could land; correctly stating which side was face-up, on the side of the eagle. Later that same year, John, and 74 other six-year-old children were "conscripted", covertly kidnapped from their homes and replaced with Flash Clones, all of which would later die of natural causes to cover up the kidnappings. John, along with the other candidates, was taken to Reach. Dr. Halsey informed them of the SPARTAN-II program and how they would be the protectors of Earth and her colonies. The next morning John discovered his service tag, stitched into his training uniform, and his new name; John-117.
John began a new life, training with other Spartans under Chief Petty Officer Franklin Mendez. For eight years he learned history, military strategy, weapons, and was given physical fitness training. Early on, he bonded with Kelly and Sam, who would be the only close friends he would ever have, aside from Sergeant Johnson.
When the Spartans were eight years old, they were sent on a training mission in which they were dropped over a forest located deep in one of Reach's snow-capped mountain ranges and expected to get safely to their extraction Pelican. The children also had instructions to leave the last child arriving behind, or the punishment would be painful, but John-117 knew that he could not do that. After telling the Spartans where to meet up, the Spartans looked to him as their leader, a role he was initially surprised to be given, but took on. When the group came upon the Pelican, it was guarded by armed men. Those men were actually UNSC Marines, but were not in uniform, and in addition to the fact that the Spartans may have never seen Marines before, therefore mistaken for a hostile threat. John showed early acumen in critical thinking and tactics, not wishing to take it for granted that guards would be friendly toward them. He came up with a plan to take the men down, capture the dropship, and ensure the safe extraction of every team member, as he made sure he was the last person aboard. To do this he ended up hijacking the dropship with the help of Déjà, and beat down the men with stones and many feet, causing severe injuries among the Marines. Chief Mendez was not visibly pleased, as John attacked his Marines and also, no one had been left behind. But both he and Dr Halsey recognized John's initiative, and promoted him to Squad Leader. After this, despite the other Spartans rising in rank and at least a couple rising to lead their own teams, he remained the de facto leader of the Spartans as a whole.
At the age of 14, John underwent the dangerous process of SPARTAN-II Augmentation Procedures that caused almost half of the Spartan candidates to die, or be physically disabled. John was one of 33 Spartans who made it through the process unscathed, while the rest who could still operate were sent for jobs in the Office of Naval Intelligence. At only 14 years old, it is said that John had a body of an 18 year old Olympic athlete; the augmentation process gave the Spartans faster reflexes, greater strength, enhanced eyesight, and made their bones nearly unbreakable. Following their augmentation procedures, John and the other Spartans were transferred to the Atlas in order to recover in a microgravity environment. During his first visit to the Atlas gym, John was confronted by four ODSTs, whose Sergeant then ordered the five of them into the boxing ring. In the ensuing fight, John killed two of the ODST's, and left the others severely injured. According to Major Antonio Silva, this incident was orchestrated by ONI in order to test the Spartans' augmentations.
Early Military CareerEdit
John-117's first mission was against rebels in the asteroid belt of the Eridanus System, where his home world was located. He was shot in the side by live ammo while leading his squad to capture rebel leader Colonel Robert Watts, without heavily injuring him. He received a Purple Heart after this mission.
Three months after the Eridanus mission, John and his Spartans were briefed on the massacre that took place on Harvest shortly after first contact with the Covenant. A short time later, the UNSC Commonwealth, under the command of Captain Wallace, brought the Spartans and Dr. Halsey to the Damascus Testing Facility at Chi Ceti, where they received the MJOLNIR Mark IV Powered Assault Armour. When a Covenant ship attacked the Commonwealth, John and the SPARTAN-IIs took part in their first battle with the Covenant. The Spartans used thrusters to launch from a Pelican dropship. Each Spartan carried an Anvil missile with them to destroy a Covenant ship. Only two other Spartans made it to the ship with John: Samuel-034 and Kelly-087. They entered the ship through a hole in its hull, caused by a heavy MAC round from the Commonwealth. They succeeded in completing the mission and destroyed the Covenant ship, but due to a breach in Sam's armor, caused by retaliation fire from Covenant forces, he was unable to leave the Covenant ship. Volunteering to stay behind and ensure the destruction of the enemy vessel, Sam is killed in the ensuing explosion. John is affected profoundly at the loss of one of his friends. This UNSC victory against the Covenant showed John that the Covenant could be beaten, but at a high cost. John and his remaining Spartans would fight the Covenant for the next 27 years, employing the MJOLNIR armor. John wearing his MJOLNIR Mark IV armor.
Sometime during the war, John, along with Fred-104, Kelly-087, Solomon-069 and Arthur-079, was part of a mission to rescue Dr Catherine Halsey from a Covenant fleet. The team utilized the Open Frame 92/Extra-Vehicular Activity, designed for space combat and infiltrated a Covenant Assault Carrier. The Spartans completed the mission and rescued Dr Halsey, but Arthur and Solomon were killed. John was saddened by his teammates' deaths and vowed to be stronger and never let something like that happen again.
John served in over 200 missions against the Covenant, including the Battle of Jericho VII, where he and a handful of Spartans single-handedly killed over a thousand Grunts, and the Battle of Sigma Octanus IV, in which John and his Blue Team detonated a HAVOK nuclear warhead to clear the Covenant Army from the city of Côte d'Azur. This was one of only a few UNSC victories against the Covenant. He received every medal the UNSC awards except for the Prisoner of War Medal. He is also considered the luckiest and the bravest of the SPARTAN-IIs.
The Battle of Reach, though brief, was of great significance for John. This is where he received the MJOLNIR Mark V armor that had been optimized for his Spartan augmented physiology. The majority of the Spartans went to the planet's surface to protect MAC generators. John, with Linda and James, were sent to a docking station to destroy an unsecured NAV database. If the Covenant obtained the database, they would discover the location of every human world, including Earth; the location of Earth was still a closely guarded secret. The NAV database was destroyed, but Linda and James were ambushed by Covenant Sangheili; James was lost, and Linda was critically wounded. John saved four other Marines on the station, including Staff Sergeant Avery Johnson. The team returned to the UNSC Pillar of Autumn and was placed into cryo sleep as the ship fled Reach and, following the Cole Protocol, went into Slipspace in hopes of leading the Covenant away from Earth.  Defense of Earth and Humanity  Installation 04 The Master Chief with Captain Keyes and Cortana on the Pillar of Autumn.
Once it had arrived safely at Installation 04, it emerged that the UNSC Halcyon-class cruiser UNSC Pillar of Autumn had been followed through Slipspace by a small group of Covenant forces, who ultimately engaged the Autumn and sent several boarding parties to board the ship. Captain Jacob Keyes ordered John to be woken from cryosleep, and tasked him with ensuring the escape of the ship's AI, Cortana, while he crash-landed the Pillar of Autumn on the unidentified ring.
Initially, fighting on Halo was between UNSC and Covenant forces, but after Captain Keyes' unwitting release of dormant Flood parasites, the majority of both forces were infected, and the fighting shifted to combating the new enemy.
John-117 was sent out by the Installation Monitor, 343 Guilty Spark, to retrieve the Index, an activation device for the Halo ring that the Master Chief is led to believe would destroy all Flood forms within a large radius. Cortana's revelation, while inserted in to Halo's Control Center, proved that Halo's true purpose is to destroy all sentient life forms in the galaxy to starve the Flood, not to kill the Flood themselves.
John soon commenced the three-side combat where the Covenant, the Flood and the Sentinels battle around the Control Room. Soon after, he returned to Captain Keyes, but unfortunately it was too late. Captain Keyes had been transformed into a Proto-Gravemind Flood form. After a short battle, the Chief retrieved Captain Keyes' neural implants which he used to activate the Pillar of Autumn's fusion reactor which would subsequently destroy the Pillar of Autumn, and also destroy the Halo ring.
After successfully destroying the fusion reactors on the Pillar of Autumn, John-117 headed in a Warthog towards the extraction point where Pelican Echo 419 would pick him up. Reached the extraction point, John-117 witnessed the Pelican spiraling down to the ground by a pair of Banshees. The Chief quickly diverts his escape towards the hangar bay which housed a Longsword fighter. Only a handful of UNSC forces survived, notably PFC Chips Dubbo, then-Staff Sergeant Avery Johnson  and Sergeant Pete Stacker .  Operation: FIRST STRIKE John-117 on the cover of First Strike.
After the destruction of Alpha Halo, Cortana and the Master Chief fled through space in the Longsword they escaped in. He discovered three cryotubes floating nearby, one containing Linda, and retrieved them. Soon after, the Covenant Flagship Ascendant Justice came into the system along with a few cruisers, some of which had possibly escaped Halo's destruction and called the flagship to Threshold. A nearby Pelican dropship docked on an asteroid floating among Halo's debris field, fired at the cruiser to distract it. After a successful escape from the Covenant battle group, John linked the two vessels and brought its passengers aboard to the Longsword. The crew of the Pelican then helped John in capturing the Covenant ship and making slipspace jump, in proximity to the gas giant Threshold, to Reach to look for surviving Spartans. John eventually locates some of his fellow SPARTAN-IIs on Reach along with Vice Admiral Whitcomb and Dr. Catherine Halsey. When they returned to the captured Covenant vessel, they jumped into Slipspace where they discovered a base belonging to the Eridanus Rebels. After receiving some repairs they escaped a Covenant assault and made their way towards Covenant space station Unyielding Hierophant.
John faced a dilemma regarding the combat data on the Flood which was given to him by Dr. Halsey. Providing regular data to Lieutenant Haverson, would protect Sergeant Johnson from possible experimentation by ONI. However providing him the complete data which contained reference to Sergeant Johnson's escape from the Flood due to his Boren's Syndrome would result in Johnson's death.
John and the few remaining SPARTAN-IIs, Linda-058 (who had been revived by Dr Halsey), Grace-093, William-043, and Fred-103, focused on finding a way to stop the Covenant from reaching Earth, the location of which has been discovered. They decided to destroy the Covenant Station 'Unyielding Hierophant. The SPARTAN-IIs infiltrated the ship, and after eleven hours on board they arrived at a temple, where a copy of Cortana warns them of a new type of guard known as "Brutes". Linda took a sniper post and the other four entered the temple. They are ambushed by Brutes, and John is nearly killed, but manages to kill their attackers. Grace is killed by a Brute Shot that the Brutes Chieftain used and John activated the fail-safe on her armor.
The team sabotaged the generator in the Hierophant and as they escaped out a side door, the fail-safe on Grace's armor activated, disintegrating several Elites and many Grunts. John, Fred, and Will were quickly spotted by three Banshees, but their Elite pilots were hit by Linda's sniper fire. The Banshees were then captured by the Spartans. John doubled back to retrieve Linda, who took down four more Elites attempting to kill John. They quickly escape, and arrive back at the Gettysburg.
Vice Admiral Whitcomb and Lieutenant Haverson piloted the Ascendant Justice straight towards the Unyielding Hierophant. Whitcomb discusses the Alamo and Thermopylae with John, then prepares to fight the Covenant off while the Unyielding Hierophant's fusion reactor detonates. Every one of the five hundred Covenant ships maneuvers in right next to the Ascendant Justice, and the Admiral draws a SMG. The Admiral and the Lieutenant die when the fusion reactor explodes. The explosion annihilates four-hundred and eighty-eight ships of the Covenant fleet, leaving only a dozen badly damaged ships to invade Earth. John leaves after witnessing Whitcomb's sacrifice, and arrives back at Earth with the last members of his team, Linda, Will, and Fred.  Battle of Earth Master Chief gives the Covenant back their bomb, and turns the tide of the Battle of Earth.
"Something's not right. The fleet that destroyed Reach was fifty times this size." —Fleet Admiral Terrence Hood
Aboard Cairo Station, John received Mark VI MJOLNIR armor and attended an awards ceremony with the newly-promoted Commander Miranda Keyes and Sergeant Major Johnson. The ceremony was interrupted by the Prophet of Regret's Fleet, initiating the Battle of Earth. John successfully repulsed Covenant boarders from the station. Upon discovering a bomb on board Cairo Station, John fought his way through several waves of Elites, Grunts, and Drones until he reached it and allowed Cortana to access and deactivate the boarder's demolition device. He gave the Covenant back their bomb by launching himself and the device, via decompression of one of the station's launch bays, toward a Covenant warship. A timely strike by Longsword interceptors opened a breach in the warship's hull allowing John to direct the bomb into the ship's power plant. He then proceeded to use the blast from the bomb to launch himself back into the UNSC In Amber Clad.
John was then deployed to New Mombasa, East African Protectorate aboard the UNSC In Amber Clad against Covenant ground forces. His Pelican drop ship was shot down by a Scarab's main cannon. John and other surviving Marines fought their way to the other Pelicans. After a rendezvous with Gunnery Sergeant Pete Stacker in the Zanzibar Hotel, in Old Mombasa, Master Chief destroyed Covenant units along the shore of the city as he chases the tracks of the Covenant Scarab. Arriving at the edge of Old Mombasa, John received a Scorpion Tank from Sergeant Major Johnson.
Fighting through numerous highway tunnels and suburbs, John reached the city center, where Marines under the command of Staff Sergeant Banks were pinned down by Covenant forces. With the assistance of the Marines and a large stockpile of weapons, John boarded the Scarab and was able to destroy it and the Covenant forces protecting it. John was then transported to In Amber Clad to intercept the Prophet of Regret's flagship. When the flagship starts to enter Slipspace, Commander Miranda Keyes is granted permission to follow it. John and all on board In Amber Clad were brought to Installation 05.  Installation 05 Master Chief on Installation 05 hunting down the Prophet of Regret
Forced to act quickly once at Installation 05, John manned a Human Entry Vehicle with several Orbital Drop Shock Troopers, tasked with locating and assassinating the Prophet of Regret. Cortana informed him of Regret's intent to fire Halo as soon as possible. He tracked the Prophet of Regret to a temple in the middle of a lake, but not before witnessing countless Covenant vehicles coming out of Slipspace, followed by High Charity. He quickly dispatched the Prophet of Regret, and escaped the temple shortly before it is destroyed by an overhead cruiser which glassed the building as John just got out of the way by jumping off the edge of the construct and into the water.
Losing consciousness and so unable to swim in the lake, he was captured by a long tentacle belonging to the Flood Gravemind. Shortly after, the Arbiter was also captured. The Gravemind appealed to the common interest that Flood and Humans share, that of not wishing the Halos to be fired. John agreed. The Gravemind then tasked both captives with locating the Index, sending them to the two most likely locations. John was sent to High Charity, interrupting a sermon by the Prophet of Truth. In actual fact, this was the least of his worries; the conflict between the Sangheili and Jiralhanae was beginning and leading the Covenant on the path to civil war. John was caught right in the middle.
John chased them through High Charity, eventually catching up to the Prophets and their Brute escorts, though only a dying Prophet of Mercy (courtesy of a Flood Infection Form) was left to tell him that Truth was headed to Earth. In an instant, John was caught between a rock and a hard place; on one hand, the Covenant had the Index and could activate Halo. On the other, Earth's chances of withstanding the fleet Truth would lead were slim to none. In the end, he followed the latter, forced to leave Cortana behind so that if Halo was activated, she would detonate In Amber Clad's engines, not wanting to risk detonating it remotely. John boarded the Forerunner ship, bound for Earth.  Return to Earth John-117 and the Forerunner Dreadnought return to Earth; with John using a piece of the Dreadnought as a shield.
After a series of firefights, captures and escapes, John escaped Truth's ship and crash landed on Earth, where he was found by Sergeant Johnson, the Arbiter, and the rest of their squad. Sergeant Johnson believed the Chief to be dead, and requested heavy lifting gear, in order to rescue the Chief, however, the Spartan was awake and battle-ready only minutes later, showing that he could recover remarkably fast. He attempted to attack the Arbiter, believing that he was still an enemy. Johnson informed him that they were now allies, as the disillusioned Arbiter and the Elites had defected from the Covenant. The Chief in the jungles on the outskirts of Voi.
John and the Marines traveled through the jungle, searching for evacuation to a nearby military base. Johnson and his team split up from John and the Arbiter, and they were later captured by loyalist Covenant Brutes and rescued by John and Thel 'Vadam. After taking heavy fire from Phantoms, a Pelican dropship evacuated the team to a UNSC base known as Crow's Nest.
The base soon came under attack, but not before Lord Hood told John his plan. Commander Miranda Keyes decided to evacuate all forces, many of whom were injured. John, Thel and the remaining UNSC Marines fought and defended the base during evacuation, planting a massive bomb to destroy the base along with Covenant forces. Master Chief fought his way through many Brutes, escaping the explosion in an elevator. He met up with several Marine survivors underground, and they escaped the base and headed for the city of Voi along Tsavo Highway, crushing Covenant resistance on their way. John-117 and Thel 'Vadam covering each others' backs.
At the Battle of Voi, John pushed through many Loyalist forces as he made his way to what was believed to be the Ark. Rather, this turned out to be a device that opened up a portal to the Ark. John destroyed a Covenant Anti-Air gun, Anti-Air Wraiths and a Scarab, allowing Lord Hood's ships to fire upon Truth's defenses. Truth fled through the portal with his Loyalists forces, while the UNSC remained behind to determine their next move.
Just as the battle seemed finished, a Flood-infested Covenant warship crash landed in Voi. John fought to contain the Flood infection, learning that the only way to contain the Flood was to destroy the warship. During the battle, Ship Master Rtas 'Vadum came to aid the UNSC. He fought off the Flood as the Master Chief was sent to retrieve Cortana from the Warship, as it was believed by most she was on board. Aided by 343 Guilty Spark, John retrieved a damaged data device and returned to Shadow of Intent. This data turned out to be a message, rather than Cortana herself. The Elites were able to stop the Flood infestation by glassing the city and several kilometers around it, much to Hood's displeasure.
The Sangheili and the UNSC watched Cortana's recording, which contained a warning that High Charity, now overwhelmed and controlled by the Flood Gravemind, was headed for Earth. However, she offered hope, with information of a way to stop the Halos from firing and neutralize the Flood threat. Convinced of the reliability of Cortana's message, John resolved to journey to the Ark while Hood mobilized remaining UNSC forces on Earth. John accompanied a joint UNSC-Elite task force through the portal aboard the Forward Unto Dawn to the Ark.  Installation 00
The Sangheili carried UNSC forces through the Slipspace portal which led to the Ark. The team was determined to stop Truth from activating the remaining six Halos. They descended in Pelicans while the Shipmaster's fleet fought hard against the Brute ships. They flew to the surface of the Ark to find the Cartographer, eliminating Covenant Loyalists and securing a landing zone for Forward Unto Dawn. Traveling in Scorpions, Warthogs and captured Prowlers, John and other Marines located the Cartographer and learned that Truth was in a Citadel. John, Thel, and joint troops successfully assaulted the fortress.
John fought through Loyalists forces and reached the top of the tower, where he deactivated part of the shield to Truth's location. Sergeant Major Johnson was captured in the battle but not killed, being spared to serve as a Reclaimer. John, the Arbiter, and the Elites deactivated the last tower of the citadel as High Charity came out of Slipspace, bringing the Flood into the battle and damaging the Elite Assault carrier Shadow of Intent.
Entering the Citadel, John and the Arbiter pushed toward Truth's location, where Miranda Keyes had forced her way in, breaking through the window with her Pelican. She managed to kill a Brute, but was soon surrounded. Truth shot and killed Keyes with a Spiker as she hesitated before killing Johnson and herself. Johnson was then forced by Truth to activate the Halos. In an unexpected turn of events, John and the Arbiter made a temporary alliance with the Flood to stop the activation of the Halos. The final Brute defenses were defeated by the Flood as John and the Arbiter reached Truth. Truth was infected by the Flood and was killed by the Arbiter while the Master Chief deactivated the rings.
The Gravemind revealed several large tentacles, laughing as he succeeded in preventing his own destruction before turning on John and the Arbiter. The two escaped. As they were leaving the citadel, John saw a vision of Cortana that led him to the exit. He learned that a replacement for Installation 04 had been built by the Ark. He decided to return to High Charity to retrieve Cortana and destroy the Ark.
"You know me. When I make a promise..." —John-117 "... You keep it. I do know how to pick them..." —Cortana
On High Charity, John battled his way through hordes of Flood forces to reach Cortana, who still had the activation Index from the first Halo ring. John made his way back through High Charity and forced the Covenant City to explode. On his way out, Cortana detected a friendly unit which turned out to be the Arbiter. As High Charity was destroyed, the Flood was believed to be defeated but not destroyed.  Firing Replacement Installation 04 The Master Chief, caught unaware by 343 Guilty Spark's sudden attack on Sgt. Johnson.
The final task for John, the Arbiter, and Cortana was to destroy the Flood by activating the replacement Installation 04. The three landed on the Halo, finding that the Flood was not defeated, but instead trying to rebuild itself on the Halo. Flood dispersal pods released Combat Forms into battle against John and the Arbiter, forcing them to fight their way up to the tower where the ring could be destroyed. During the battle, Sergeant Johnson arrived on the Halo aboard Forward Unto Dawn. The Master Chief and Thel 'Vadam jump into Forward Unto Dawn in order to escape Halo.
Johnson helped the Master Chief and the Arbiter fight using a SPARTAN Laser. 343 Guilty Spark opened the door to the Control Room and locked the Flood out. Once inside, however, Guilty Spark realized that the team intended to fire the Halo before it could be completed. His "protocol" forced him to stop Johnson from activating Installation 04. He knew that a premature firing would destroy the Ark and so he shot Johnson, locked out the Arbiter from the room, and attempted to kill John, weakening his shields. Spark declares that the Chief is "the child of my makers, inheritor of all they left behind. You are Forerunner," but declares ownership of this ring. John stood his ground, even after being hit by several blasts, and fought. Just as the Monitor seemed invulnerable, Johnson shot the Monitor, temporarily distracting him. He then handed off the laser, and John finished off Guilty Spark. Johnson's injury was fatal, and he requested that John send him out "with a bang" after handing over Cortana's data chip and imploring him, "Don't ever let her go."
Cortana activated Installation 04 and they fled the Halo fighting Flood the whole way. Both Cortana and the Arbiter gave their condolences for the loss of Johnson. The team boarded Forward Unto Dawn and escaped the explosion of Installation 04. However, the slipspace portal opened for them could not sustain itself during the explosion, and its closure severed the ship in half, sending the Arbiter on to Earth and leaving John and Cortana drifting towards a nebula and an unknown planet.  Missing in Action
"But you did it. Truth and the Covenant and the Flood. It's finished." —Cortana to John 117
John and Cortana were presumed dead when they did not make it back to Earth. The cockpit portion of Forward Unto Dawn, bearing the Arbiter, crash landed on Earth. Lord Hood commissioned a memorial near Mount Kilimanjaro in Africa. Due to having no records to remember him by, the Chief's Spartan ID number, 117 was carved into the memorial by an unknown party, and taped beside his number was the UNSC Master Chief Petty Officer of the Navy insignia patch. Ironically, he and a few other Spartans are the only ones literally MIA.  Survival
"Wake me... when you need me." —John's last words to Cortana.
John and Cortana did in fact survive the explosion of Installation 04 (II) in the remaining cargo portion of the Forward Unto Dawn, but it was nearly powerless and, without airlocks or a bridge, could not be properly navigated. Cortana, relieved that John survived, explained this to the Chief, and that it could take years before anyone could discover their distress signal. John stowed himself in a cryotube, at which point Cortana said "I'll miss you." John replied with, "Wake me... when you need me." This leaves the series off exactly as it started, making a reference to Halo: Combat Evolved where John made his first appearance climbing out of a cryotube, whereas he climbs into one in this cutscene. In 2557 Cortana talks to John while he is still asleep.
In Halo 3's Legendary ending, you can see the half of the Forward Unto Dawn approaching an unidentified planet.