Master Sergeant Marcus P. Stacker (service number 41009-31545-MS) is a veteran UNSC Marine and Orbital Drop Shock Trooper who fought during the Human-Covenant War and the subsequent conflicts. As of July 2557, he was stationed on the UNSC Infinity.
Fall of Reach
Stacker served during the Siege of New Alexandria on the 23rd of August, 2552, under the call sign "Kilo 40".[Note 1] He participated during the Siege of New Alexandria, communicating with Kilo 26 and Kilo Dispatch, and along with several other units, assisted in the evacuation of civilians from Traxus Tower. Stacker was in charge of managing the elevators and ordered Kilo 26 to fire on an overhead SDV-class corvette. The artillery fire was unable to prevent the Corvette from inflicting heavy damage on Traxus tower, a major evacuation point within the city. Stacker coordinated the evacuation of a group of civilians in a building adjacent to the tower, before advising Lieutenant Spartan-B312 to assist an ODST Air Assault unit in securing the tower's executive landing pad for civilian evacuation. 
Battle of Installation 04
When the Pillar of Autumn arrived at the Soell system and discovered Installation 04, it quickly came under attack by the Fleet of Particular Justice, who had pursued it to the system. The ship was soon boarded by innumerable boarding craft, and Captain Keyes was forced to give the order to abandon ship. Stacker was presumably among those who made it to the surface of the ring alive and intact, and was able to link up with other surviving elements of the Pillar of Autumn's crew and complement, who went on to mount a guerrilla resistance against the Covenant.
Both the full extent of Stacker's participation in the battle[Note 2] and the method of his survival are unknown, as he was not on-board John-117's Longsword or Shiela Polaski's Pelican, the only two known UNSC craft to escape.
Battle for Earth
A clean-shaven Stacker was present at the October 20th awards ceremony on Cairo Station, minutes prior to the Battle for Earth beginning. Outfitted in his official Naval uniform, he aided SPARTAN John-117 and Sergeant Major Avery Johnson in defending the station's command center from Covenant forces. While accompanying Johnson and Commander Miranda Keyes to board the frigate UNSC In Amber Clad, the party was ambushed by Covenant and pinned down. John-117's timely arrival and aid allowed the In Amber Clad's leadership to board safely.
During the Battle for Earth, Stacker served in the 7th Battalion of the 105th Shock Division. He was dispatched from the In Amber Clad under the command of Sergeant Major Johnson, leading a squad of ODSTs in a Pelican. Upon entering a section of the city under heavy assault by the Covenant, Stacker's Pelican was shot down by a Scarab over Old Mombasa and crashed landed on an open beach near Hotel Zanzibar, killing the pilots and one of Stacker's squad. The surviving four ODSTs were immediately engaged by a Covenant patrol led by a Sangheili Minor. During the brief assault, the Sangheili held one of his troopers hostage momentarily before Stacker shot the Sangheili in the head.
Stacker and his squad then holed up in the nearby Hotel Zanzibar, following the instructions of UNSC AI Cortana while Spartan John-117 cleared a path to them. They were soon attacked by another group of Covenant infantry, and were pinned down in the hotel's lobby by a plasma cannon by the time John-117 arrived. Stacker then assisted the Chief in clearing the nearby beaches and tunnels of Covenant.
Later in the battle, Stacker once again crossed paths with John-117 in New Mombasa. Caught alone behind enemy lines, Stacker was driving a Gauss Warthog through a Covenant-filled park when he encountered the Chief and a squad of Marines emerging from the nearby tunnels. He suggested the SPARTAN-II commandeer the Gauss cannon, and assisted him in liberating the nearby Marine command post, which was under the bombardment of several Wraiths, reinforced by waves of Ghosts. Clearing out the attacking Covenant, they reached the command post, where Stacker remained as John-117 lead survivor Sergeant Banks and a squad of marines in pursuit of the Scarab walker.
Stacker was preumably evacuated to In Amber Clad alongside the survivors of A Company's First Platoon. Minutes later, the ship pursued the Prophet of Regret's carrier through a slipspace portal that inflicted heavy damage upon the city.
Battle of Installation 05
Stacker was among the fist wave of UNSC forces deployed on Installation 05.  The Gunnery Sergeant, alongside Spartan John-117 and several ODSTs from First Platoon, made a hard drop on the Halo Ring and secured multiple Forerunner ruins. The ODSTs suffered almost total casualties upon insertion, however their efforts allowed vehicular support and armor to be delivered via Pelican. Stacker and his surviving troopers supported the SPARTAN-II as he pushed through heavy Covenant defenses on the way to his target; the Prophet of Regret. Upon discovering the location of Installation 05's Library, Commander Miranda Keyes ordered Sergeant Major Avery Johnson to extract his forces and rendezvous with the In Amber Clad for a retrieval operation. Alongside the majority of the forces supporting John-117, Stacker was pulled out via Pelican and headed towards the Library.
After rendezvousing with In Amber Clad, Stacker lead a Platoon-sized force of Marines into the Sentinel Wall surrounding the Quarantine Zone. The Marines moved through the outer wall with ease, unmolested by local Sentinel defenses - likely due to being recognized by the automated guardians as Reclaimers. As the Marines moved through the inner wall however, the outer wall became besieged by Jiralhanae-led Covenant forces deployed from the recently arrived High Charity. Eventually, the Arbiter Thel 'Vadamee was able to deactivate the Containment Shield, and the inner wall quickly became overrun with Flood from the nearby Quarantine Zone.
Spread throughout the wall in small fireteams, Stacker's men swiftly fell to the Flood parasite and the now-hostile Sentinels. With his force decimated but the Containment Shield now disabled, Stacker contacted In Amber Clad suggesting Keyes proceed straight to the Library while his troops attempted to hold their position. As he relayed the message, Stacker was set upon by a Flood Infection Form, screaming for his Marines to remove it from him. A short time later, Stacker made contact with Keyes once again, confirming their engagement with non-Covenant hostile lifeforms, while Staff Sergeant Banks and other Marine survivors could be heard staging a desperate defense. It is unknown how Stacker escaped the Quarantine Zone, however himself, Banks and his surviving Marines were ultimately captured by Covenant forces.
Later, as High Charity was overrun by the Flood-infested In Amber Clad, captive Sergeants Stacker, Johnson and Banks were brought to a series of structures held by the Jiralhanae. The three were moments away from execution when the Jiralhanae were attacked by Sangheili forces lead by the Arbiter Thel 'Vadamee. Taking advantage of the confusion, Johnson managed to board the nearby Scarab walker, and forged a hasty alliance with 'Vadamee in order to stop Tartarus from activating the installation. The UNSC-operated Scarab cleared a path to the Installation's Control Room, while the Arbiter provided air support. After the neutralization and subsequent blockading of Installation 05, Stacker was presumably evacuated by the Arbiter and his allies alongside Johnson and Miranda, returning to Earth around November 15, 2552.
Back to Earth
Stacker remained under the command of Sergeant Major Avery Johnson, serving as his second-in-command as they were stationed back on Earth. Late in the Battle for Earth in Kenya, Johnson, along with Stacker, led a Marine force that recovered John-117 after his atmospheric landing. Stacker led First Squad, acting as scouts for Johnson's company, before Covenant Phantoms forced Johnson to divide his forces. Stacker and First Squad followed John-117 and Thel 'Vadam through the jungle and saved Bravo team's only survivor, Gunnery Sergeant Reynolds. After rescuing a captured Sergeant Johnson and the remains of Second Squad, Stacker was evacuated to Crow's Nest.
Stacker led a squad of Marines defending the operations center during the Covenant's assault on Crow's Nest. During the battle, he was sent to lead a supply convoy escaping the base en route to nearby Voi. Shortly after leaving the besieged base, the convoy became under attack by Banshee fliers, losing multiple Warthogs to their continued strafing runs. They eventually ran into a Covenant blockade, and Choppers, Shade turrets and large numbers of infantry decimating the convoy and pinning the survivors down in several small structures. Having received Stacker's distress call, John-117 arrived to assist, accompanied by Gunnery Sergeant Reynolds and other Marines fleeing the fallen Crow's Next. Stacker rallied his survivors and assisted the arriving forces in neutralizing the Covenant fortification. The UNSC convoy continued onward, but were forced to leave their vehicles shortly after, stopped by a destroyed section of the highway. Continuing on foot, Stacker, Reynolds and their men helped John-117 liberate another squad of Marines under attack in a nearby building complex. After holding off many waves of attacking Covenant troops, including a Wraith tank, several resupply Pelicans moved in, delivering multiple Warthogs and reinforcements. Mobilizing once again, the UNSC forces assaulted the Covenant-held Tsavo Highway, clearing a path to Voi.
UNSC forces lead by Reynolds and Stacker supported John-117 in the assault on Traxus Factory Complex 09 in South Voi.[Note 3] There, they eliminated a heavy Covenant presence, including multiple Anti-Aircraft Wraiths and a Scarab. Passing through a UNSC forward operating base, Stacker preceded to aid John-117 in fighting through a Covenant-held factory interior, rescuing multiple civilians in the process.[Note 4] After eliminating a Mgalekgolo pair and two Jiralhanae War Chieftains, the UNSC troops were able to neutralize an anti-air battery, paving the way for what remained of Lord Hood's Home Fleet to engage the Forerunner Dreadnought above the Portal.
Moments later, when a Flood-infested CCS-class battlecruiser crashed in the area, Stacker and his retreating men were pinned down in the factory interior as Flood combat forms and infection forms assaulted them.[Note 5] No stranger to battling the parasite, Stacker valiantly used a shotgun against the Flood until the Master Chief and the Arbiter returned to the factory complex. After liberating two large warehouses, the Marine survivors held their position as the Spartan and Elite proceeded to the crash site. Stacker was evacuated to the Forward Unto Dawn, before the Covenant Separatist Carrier Shadow of Intent glassed the city and surrounding area. .
Battle of Installation 00
During the Battle of Installation 00, Sergeant Major Johnson organized a makeshift UNSC armored unit from the UNSC Forward Unto Dawn for an assault on the Ark's Cartographer. Stacker commanded the platoon of Scorpions against a battalion-sized Covenant armored force outside of the complex and managed to eliminate a Scarab with John-117's help.
Later in the battle, he led an Orbital Drop Shock Trooper squad accompanying John-117 in the three-pronged assault on the Citadel's shield generators. The small force were able to storm the Covenant-held beach, mount vehicles, and fight their way into the highly-fortified generator tower high in the hills. After clearing the structure interior of a large pack of Jiralhanae, Stacker and his men fell back to guard the entrance while the SPARTAN ascended the tower. After disabling their target, John-117, Stacker and his troopers boarded Hornets and helped the Arbiter's force liberate the third and final tower.
After the plan to destroy the Citadel from orbit failed, John-117 lead a combined force of ODSTs, Marines and Sangheili in a desperate assault on the Citadel. They fought through heavy Covenant fortifications and destroyed 2 Scarab Platforms, clearing the way for John-117, the Arbiter and 343 Guilty Spark to enter the citadel and stop the Prophet of Truth from firing the rings.
Stacker escaped back to Earth aboard the Shadow of Intent along with the rest of the Forward Unto Dawn's surviving crew. He was last seen attending the memorial for the UNSC fallen and was in charge of a three-volley salute, in tribute to his fallen comrades.
Conflict on Requiem
In the years after the Human-Covenant war, Stacker's service throughout the long conflict was recognized with a promotion to Master Sergeant. By February 21 2557 Stacker was assigned to the UNSC Infinity as it was tasked with finding and decommissioning the rest of the Halo Array.
When the Infinity was caught by the gravity well of the shield world Requiem in July 2557, Stacker survived the ship's impact, as well as the subsequent assault on the crashed ship by Promethean and Jul 'Mdama's Covenant forces.
Later, during the Infinity's assault on several particle cannons and the gravity well generator, Stacker remotely commanded a platoon of armored vehicles making a ground assault on Jul's Covenant forces. The group had taken heavy losses when Master Chief John 117 arrived, and Stacker ordered his troops to rally behind the Spartan-II. With John-117's aid and Stacker's direction, the force was able to push through multiple waves of Covenant armor and clear a path to the generator.
Personality and traits
Identified by his strong southern American accent, Stacker is a tough, charismatic Marine. He is easily able to inspire confidence in his troops, often with jests or taunts at the enemy. A dependable leader in the face of adversity, Stacker has survived important roles in countless major battles. Having survived the Human-Covenant War, as well as engagements against Flood, Promethean and Covenant remnant forces, Stacker is one of the more hardened veterans in the entire UNSC.
Stacker has served alongside Spartan-II John-117 on many occasions, often providing assistance in vital situations. Having firsthand experience of John-117's prowess on the battlefield, Stacker has often directed troops under his command to follow the Master Chief's lead. Whether it be offering a vehicle, weapon, or compliment, Stacker displays tremendous respect for the Spartan.
In-game, Stacker behaves and acts just as any other Marine NPC would, though like other Marine Sergeants, he will sometimes pause to shout and motion orders to other Marines. The player can trade weapons with him (in games where it is possible), and he can be killed during the course of gameplay. If he is killed, he will reappear in later appearances regardless, even within the same level.
Additional Appearances in Halo: Combat Evolved
The full extent of Stacker's participation in the Battle of Installation 04 are unknown, as he does not appear in Halo: The Flood depiction of events, nor is his presence guaranteed in his Halo: Combat Evolved appearances (with the exception of his appearance representing Waller.) He was also not on-board John-117's Longsword or Shiela Polaski's Pelican in Halo: First Strike the only two known UNSC craft to escape the destruction of the ring, despite participating in the Battle of Earth a month later.
Stacker can appear as one of a pair of Marines guarding the first lifeboat bay encountered. The door will explode outwards via a plasma grenade detonation, killing both Marines as a Covenant lance boards the Pillar of Autumn.
Stacker can appear in a group of crash-landed Marines in the level Halo, who's Bumblebee lifeboat made landfall near a small Forerunner structure. The Marines were quickly located by Covenant dropships, and forced to move into the adjacent hills, where they were able to hold out until John-117 arrives and dispatches the Covenant attackers. Stacker and his men are evacuated via Pelican, and able to link up with other surviving elements of the Pillar of Autumn's crew and complement, mounting a guerrilla resistance against the Covenant.
Stacker leads a large Marine force in The Silent Cartographer, assaulting a heavily-defended Covenant beachhead. Stacker's Marines provide support to John-117 throughout his mission to locate the Cartographer, while the Sergeant remains on the surface with the main Marine force, ready to provide reinforcements. While the Spartan is deep in an underground Forerunner structure, Covenant dropships are sighted approaching the island, too swiftly for the Marines to retreat into the structure. Stacker implores the Spartan to locate his objective, and states his forces will delay the incoming Covenant for as long as possible. By the time John-117 reaches the surface, the entire Marine force including Stacker have been killed.
Stacker may appear among a large Marine force encountered in the level Assault on the Control Room, though without his namesake voice actor. The Marines are fleeing from a pair of Hunters when John-117 arrives, accompanied by Fireteam Zulu. The Marines aid the Spartan assault a valley heavily fortified by Covenant, before Cortana sends a distress signal and orders the Marines to hold position for extraction.
Stacker may appear among the Marines encounter on the surface in the level 343 Guilty Spark. The Marines are holding position inside a Forerunner structure when John-117 emerges from an elevator. They proceed to accompany the Spartan through the flood-infested jungle, moving towards a large tower so Echo-419 could provide extraction.
Stacker takes his first name from Marcus Lehto, after whom his face was modeled in Halo: CE and Halo 3, and his middle initial and surname from Pete Stacker, the voice actor who plays him in every one of his appearances. Pete Stacker also voices a number of other characters in the Halo universe, including Jacob Keyes, Echo Four, Oscar 18, Gunnery Sergeant Waller and a number of unnamed NMPD officers and Marine Sergeants in Halo 3: ODST. Pete was not credited for playing Sergeant Stacker in Halo: CE; instead, he only receives credit for his portrayal of Jacob Keyes. The character was first named in Halo 2's credits, where Pete Stacker is credited for portraying "Sergeant Stacker". Halo 3 lists him as "Marine Sergeant", In Halo: Reach, he is credited as "TROOPER SGT 1". Reach also established the character's true rank to be Gunnery Sergeant, since he is listed as thus in The Armory. The characters first name and middle initial were revealed in the Halo 4 level Reclaimer.
Stacker appears outfitted in both standard Marine attire and ODST Armor at different points in Halo 2 and 3. Strangely, he is depicted as a regular Marine during the Halo 2 level Outskirts, yet he and his fireteam wear ODST armor in the cutscene Another Day at the Beach. This could be a symptom of Bungie's hesitance to include Orbital Drop Shock Troopers in Halo 2 during it's development, despite pressure from the Microsoft Franchise Development Group. Stacker and his squad's appearance as Orbital Drop Shock Troopers in the remastered version of Another Day at the Beach likely confirms the cutscene as the definitive depiction of events.
List of appearances