Edward Buck

"But you let him live. Because you're not only a Spartan, you're the best kind. The kind with the potential to save us all. You may be a Spartan, but you're goddamn human, too, and that's something you should be proud of."

- Musa Ghanem to Edward Buck, commemorating him for sparing Michael Crespo

Spartan Edward Malcolm Buck (service number 92458-37017-EB) is a SPARTAN-IV supersoldier who served with the UNSC Marine Corps throughout the Human-Covenant War, the last years of which he spent as an Orbital Drop Shock Trooper.

Counting time spent in cryo-sleep, Buck was a 25-year veteran of the Covenant War and served in numerous battles. Regarded as an extremely skilled Marine, by the Battle for Earth, he was the leader of a small specialized fireteam, Alpha-Nine, which was appropriated by Captain Veronica Dare for a classified ONI mission before the drop on New Mombasa, Kenya in October 20, 2552. Following the war, Buck was promoted to SPARTAN-IV and eventually joined Fireteam Osiris, led by Jameson Locke. By August of 2558, he had completed 188 military operations, including 49 full campaigns. With the onset of the Created conflict, Buck left Osiris, reformed Alpha-Nine and married Dare, his long-term girlfriend.

Early life
Edward Malcolm Buck was born on August 22, 2510 to working-class parents in Draco Mercy in New Albany, Lombard on Draco III. Buck's father was a dockworker and his mother formerly served in the UNSC Marine Corps, until she retired to raise Buck and his younger sister, Lucy. During his summers, Buck apprenticed with his uncle Lou as a fisherman on Draco's Gold Sea. Serving aboard an industrial fishing ship, Buck and his uncle worked to catch the massive naeori that dwelled in the sea. During one of the fishing runs, a crew member of the ship fell into the sea. To prevent her attached safety line from snapping, Buck grabbed it while Lou hauled her back into the ship. Afterwards, Buck performed CPR on her until she coughed up the water in her lungs. Buck's last known place of residence is Karnak on Draco III, where he is also a citizen. His civilian occupation is listed as student. When he was young, he used to play a fair bit of football on Draco III.

Early military career
On December 5, 2528, at the age of eighteen, he enlisted in the UNSC Marine Corps. The night before he had to report to the UNSC for the first time, his father and uncle Lou threw him a going away party at the Leeward's dive bar. It resulted in him still being intoxicated when he reported to the recruiter's office the next day. Upon enlisting, he trained at several training facilities at Earth and Reach. In sniper school, Buck earned the top marks of his class. After the Covenant invaded Madrigal in 2528, Buck was deployed to assist in its defense. At an unspecified date following his enlistment, Buck participated in Operation: ABLE SENTRY, a force reconnaissance mission to prepare the way for Operation: PHALANX, which involved the evacuation of civilians and observation of enemy invasion patterns on Circinius IV.

Buck would serve in many more battles throughout the Human-Covenant War, including the Harvest campaign. During this campaign, Buck and his unit were posted at the ruins of the capital city of Utgard and he was later commended for his actions during the Liberation of Harvest. While at Utgard he was part of Operation: ASTUTE TIGER, which revolved around the placement of ADMs at predicted Covenant landing zones during a UNSC evacuation.

Though the efforts to retake Harvest would not end until 2531, Buck would be called elsewhere in the midst of it. On December 24, 2530, he was attached to Admiral Preston Cole's fleet during the Battle of the Great Bear over Groombridge-1830. He was part of one of two tactical strike teams which recovered a Sangheili survivor within an enclosed compartment which had survived landfall at Waterford, Lemuria on the planet that day at approximately 1805 hours MST. It was from this Sangheili, dubbed Subject 386, that the UNSC first truly learned why the Covenant was waging a war of extermination against humanity. In 2532, Buck fought in the Battle of Vodin. During that same year, he enrolled in an enlistment survey program for the ODST program. Three years later, he participated in the Battle of Charybdis IX. Come 2542, he found himself fighting in the Battle for Alluvion.

At some point prior to 2545, Buck's father was killed in a traffic accident. In 2545, after an extended period of cryosleep during a slipstream space jump between Mars and Hardscrabble, Buck learned of the Covenant attack on his homeworld and the slaughter of all its citizens, including his family and relatives. He obsessively watched video footage of the Unggoy and Kig-Yar hunting down and devouring the human survivors, which fueled his hatred of the Covenant and further steeled his fighting resolve. He requested an offical transfer to the Orbital Drop Shock Troopers immediately afterwards; his request was granted three weeks later, on February 27. He was placed in the 103rd Battalion of the 65th Shock Troops Division. His commanding officer ordered Buck to take some shore leave, claiming that his presence was "jeopardizing others". Only when she threatened to send him in for a psychiatric evaluation, did he relent. He took his shore leave at Castellaneta, over Saturn, where he first met Captain Veronica Dare. The two spent their week together, until Buck eventually realized that she worked for the Office of Naval Intelligence. Buck had hoped their fling wouldn't end after their leave was over, but his poor reaction to Dare's job ensured their relationship was over, a decision that continued to haunt Buck throughout all of his career. The two were eventually forced to split up due to Dare's job with Section One of ONI. Buck soon gained command of the ODST squad Alpha-Nine. Throughout the remainder of the war, Buck intentionally sabotaged and turned down numerous promotions in order to remain a squad leader.

Battle of Sargasso
During the battle on Sargasso in 2546, Dare tasked Alpha-Nine—then composed of Buck, Gomez, Svensdottir, and Samrat—with retrieving Lethbridge Industrial's research data from its laboratories in the town of Belisk before the Covenant did. Fellow ODST squad Gamma-Six was charged with unknowingly distracting the Covenant, while Alpha-Nine retrieved the data chip. Buck voiced his disapproval of the mission, as he was reluctant to allow Gamma-Six to die on what was essentially a suicide mission. Buck eventually relented and Alpha-Nine was covertly dropped off by a dropship five kilometers away from Belisk, rather than being deployed in Human Entry Vehicles from orbit. The squad reached Lethbridge's headquarters in the town and, after eliminating scattered Covenant forces, Buck retrieved the data chip.

As Alpha-Nine completed their mission and prepared to leave the town of Belisk, Buck overheard Sarah Palmer of Gamma-Six questioning Command about their lack of extraction. Command informed Palmer that the amount of hostiles at her position made extraction infeasible, and ordered for her to retreat to a safer location. Buck ignored ONI's orders and led his squad to rescue Palmer and Gamma-Six. By the time Alpha-Nine arrived, Palmer was the last remaining member of her squad. Together, the ODSTs eliminated the Jiralhanae, Kig-Yar, Unggoy and Banshees assaulting their position and returned back to base in a civilian truck. Buck was reprimanded by Dare for disobeying her direct order and he was threatened with a charge of insubordination, but he did not receive any other apparent punishment.

Fall of Reach
At some point between the Battle of Sargasso and the Fall of Reach, Buck fought during the Covenant's attack on Bounty. He was then present along with the rest of Alpha-Nine during the Fall of Reach in August 2552, where he served with the 11th Shock Troops Battalion. During the battle, squadmate Baruti "Gramps" Komen was killed. At the time of his death, the squad was merely holding a piece of ground for reasons undisclosed to them, leaving Buck to later wonder if Baruti had died for a noble cause.

He participated in the failed defense of New Alexandria as part of Operation: SWORD 52, during the Covenant's assault on the city. On August 23, he requested assistance from SPARTAN-B312 of NOBLE Team. After receiving assistance from the Spartan, Buck left the center of the city. Buck and the surviving members of Alpha-Nine were later evacuated as Reach fell to the Covenant, escaping to Earth. At some point just before the fall of the planet, Buck met Jun-A266.

Battle of Mombasa
During the early stages of the Battle of Earth on October 2552, Buck's squad was attached to the 65th Shock Troops Division that was to be inserted from the onto the Prophet of Regret's flagship, Solemn Penance, which was stationed over the city of New Mombasa, as part of Operation: BUMRUSH. His mission changed when Veronica Dare, now a captain in the Office of Naval Intelligence, took control of the squad immediately before the orbital drop, in order to use them for her own classified mission. At 1602 hours, BUMRUSH was greenlit, but during the drop, Dare ordered the squad to adjust their SOEIVs trajectory away from the assault carrier. Immediately after this, at 1603 hours, the carrier jumped into slipspace while above the city, generating a massive electromagnetic pulse that disabled the pods' electronic systems. As a result, the pods were scattered throughout the city. After the EMP, Buck's pod ricocheted off the side of a building and landed upside down into Sector 6. He immediately made radio contact with Dare, whose hatch malfunctioned and would not open. After a brief discussion, he realized that Covenant forces were heading for Dare's crash site. On his way to the crash site, he found the corpses of several Sangheili; upon asking Dare about the matter, and noting that the Jiralhanae appeared to be responsible, Dare told him that the information was classified. Later, Veronica contacted him, telling him the Covenant had found her and were moving in on her location. After fighting his way through a large unit of Covenant, including a Hunter pair, he made it to Tayari Plaza, Dare's crash site, where her pod was under fire by a trio of Unggoy. After dispatching the Unggoy he opened up her pod to find it empty. A Huragok approached him holding Dare's damaged helmet, and Buck backed away from the Engineer before Romeo, on a balcony overlooking the crash site and believing the Huragok to be hostile, shot it through the head.

Buck abandoned Dare's original mission, initially thinking her to be dead, and focused on reuniting with his squad and evacuating the city. He and Romeo eventually made their way to the building housing the New Mombasa Police Department's headquarters, where he made contact with Dutch and Mickey via an NMPD officer. Dutch and Mickey, who were at the ONI Alpha Site, offered Buck an air evac. via a Pelican. On the way to the landing zone, Buck tried to contact Jonathan Doherty, but received no response.

When Dutch and Mickey's dropship arrived at the NMPD headquarters, it was ambushed and shot down by two patrolling Banshees. Romeo and Buck then moved through the NMPD Headquarters to find and rescue their squadmates on top of a neighboring skyscraper, defending it from waves of Covenant aircraft and infantry assaults. During the ensuing fight, a Jiralhanae Chieftain badly wounded Romeo with its gravity hammer, puncturing one of his lungs with its hind-blade, before being fatally stabbed in the neck by Buck. Buck then led the other ODSTs to Kikowani Station, intending to take the train out of the city, but found that the train tunnels had been flooded. He decided to have his squad steal a Phantom dropship to escape the city and escorted them with a stolen Banshee. As they made their way out of the city, Buck flew up to where he could see a Covenant fleet in the distance and wondered what they were looking for. Continuing with the escape, Buck killed many Huragok in their recharge stations on the way out. They encountered a Scarab as well, which Buck destroyed. After finally making it out of the city, he realized where Dare might be and ordered Mickey to fly the captured Phantom back into the city.

He headed into the Superintendent's Data Center alone, going right through the Yanme'e hive. When he neared the Data Center's infrastructure he was reunited with Dare, Jonathan, and the Huragok that had absorbed the Superintendent's subroutine, Vergil. Unaware as to the importance of the Huragok, he had a quick conversation with Dare as to why Vergil was so important, letting slip to Dare that he had killed "one or two" Huragok on the way, much to her annoyance. After finally making it to the elevator, Dare punched Buck in the face, for "abandoning the mission"; a furious Buck complained that she had been missing in action, and that his squad was scattered only to be cut off by Dare, who gave him a passionate kiss for "coming back". Remembering Jonathan and Vergil were present, and that they were rather awkwardly watching, he congratulated the former on doing a good job.

After battling through a Covenant outpost, and boarding another elevator for the highway, the presence of the Covenant fleet was revealed to Dare. Irritated that Buck had neglected to inform her of the fleet, the two began arguing again, Buck protested that he had been preoccupied with keeping the helpless Vergil alive. Taking the gunner position on various Warthogs and a Scorpion tank, Buck and Jonathan covered Dare and Vergil's Olifant, which they commandeered, down the coastal highway, witnessing the arrival of more Covenant ships—including two assault carriers—and marveling at their size. Upon seeing a carrier beginning to glass the city, he was reminded of Reach and briefly began to panic before Dare calmed him down. The Olifant was later severely damaged by a Scarab. Knowing that the Covenant had glassed the highway farther along, Buck ordered Mickey to meet them at the entrance to the Uplift Nature Reserve.

Buck and the others took the next exit off the highway, and Jonathan and Buck secured a building to hold and wait for Mickey's dropship to arrive. After fighting off waves of Covenant, Mickey arrived, and as the squad was evacuating, an assault carrier arrived close to their position. A frightened Vergil then refused to get on the Phantom, and was shoved in by Buck while Dare pulled it into the gravity lift. The group successfully escaped the city as it was glassed by the Covenant fleet.

Respite and redeployment
Buck and his squad guarded Vergil in the ONI-appropriated Crimson Wing of the Quito Space Tether's terminus for the following weeks, giving him time to catch up with Dare after spending six years apart. Approximately one month after the battle, they watched as Sergeant Major Avery Johnson interrogated the Engineer. Shortly after this, Alpha-Nine was redeployed in the field and fought in the concluding battles of the war. One of these operations, known as Operation: JOINT MONITOR, consisted of biohazard containment in the Voi Exclusion Zone, at some point following the Battle of Voi.

Post-Covenant War
After the end of the Covenant War in 2553, Buck and Dare traveled to Sundown for a vacation together while on shore leave. Near the end of their vacation, on February 15, 2553, Jun-A266 met with Buck and offered him the opportunity to join the first class of the new SPARTAN-IV program. To Jun's surprise, Buck declined the offer, as he felt that he might have to abandon his team and Dare. Buck was the first individual that declined Jun's offer to join the SPARTAN-IV program.

In 2554, the United Rebel Front attempted to take control of Draco III, which was finally being settled for the first time in nearly two decades. Dare sent Buck to lead the mission to eliminate the rebels on the planet, as he was one of the few Draconians left. Returning to Draco for the first time in years, Buck and the rest of Alpha-Nine traveled to New Albany and stormed the insurgents' headquarters established in the city's capitol building. After breaching their way into the building's legislature chambers, their entrance was quickly blocked off by some rebels. Buck sent the Rookie to secure the emergency exit, but he was ultimately captured and held at gunpoint by Captain Ingridson, the leader of the United Rebel Front on the planet. Spartan Sarah Palmer, who was battling insurgents elsewhere in the city, contacted Buck and offered her assistance with the situation.

However, Buck declined the aid as he believed that the appearance of Spartans would lead to the Rookie's execution. As a stand-off ensued, the URF soldiers were positioned safely on the presidential balcony, which was protected with energy shielding. Buck signaled for Dutch and Mickey to sneak up to the balcony, while he and Romeo distracted Ingridson. Buck and Ingridson engaged in a conversation about each others' views, with both individuals attempting to stall the other. Buck soon learned of Ingridson's intent when Palmer notified him that URF soldiers were surrounding the capitol building. Once Dutch and Mickey got into position, Buck ordered the squad to attack the rebels while having Palmer and her Spartans engage the approaching rebels outside. In the ensuring firefight, Buck was shot in the arm. Realizing she was out of options, Ingridson executed the Rookie. Dutch managed to kill Ingridson and one of the rebels, while the last one surrendered. Palmer and her Spartans arrived seconds later, having wiped out the rest of the rebels in the city. Afterwards, Alpha-Nine buried the Rookie out at sea on Draco III. Troubled by his death, Dutch decided to retire alongside his wife.

After the funeral, Buck returned to his former city of residence, Karnak. While he was at Leeward's, Jun visited him and the two shared baijiu together to honor the Rookie. Jun confirmed that Buck turned out to be the only candidate to turn down the chance to be part of the first class. Buck maintained that his answer was the same a year later, but Jun informed him that the increased funding in the program allowed for the remainder of Buck's team to become Spartans alongside him, and were he alive, that the Rookie certainly would have been offered a spot. With his largest concerns alleviated, Buck asked for Dare's opinion and with her blessing, decided to join the program.

At some point between the end of the war and 2555, he participated in reconnaissance and strike operations in an unknown Joint Occupation Zone as part of Operation: KINETIC STORM.

Becoming a Spartan-IV
After spending a week-long vacation on Desdoron V with Dare, Buck departed to Mars where he underwent the necessary augmentations alongside Mickey and Romeo. During his last recovery round, Dare visited him and warned him that an unknown individual covertly loyal to the United Rebel Front had succeeded in becoming a SPARTAN-IV. Buck and the rest of the Spartan trainees were transported to a space station orbiting a dwarf planet for further training. With Captain O'Day serving as their drill instructor, the Spartans were trained to break their bad habits that they had formed over their military careers. After a training exercise, Buck was nearly ready to leave the infirmary when medics carried in the mutilated body of Hideo Wakahisa, a Spartan that Buck had become acquainted with. Speaking with the medics and one of the doctors present, Buck was told that Wakahisa was found in the training chamber with the electronic locators under his jaw torn out. Moments later, Commander Musa-096 ordered for all trainees to return to their quarters. While waiting for the situation to be sorted out, Buck, Mickey, and Romeo were visited by Jun and Musa. Although they had found a medallion belonging to Mickey on the body of Wakahisa, Buck, Romeo, and Mickey insisted that the latter was not responsible for the murder. Using the time Mickey had last seen the medallion as a starting point, Musa ordered Jun to search the station's security footage of the locker room to find any further leads. Musa later had Jun assign the three Spartan trainees to a temporary quarters until the situation could be solved.

Rudolf Schein was soon proved responsible for the murder and Jun, Musa, and O'Day went to confront him. However, Schein was waiting for them at the recreational room with the intent to blow up the station, and a skirmish ensued. Buck and his team heard gunshots from their room and the three raced to its place of origin. Before the Spartans reached the rec room, O'Day warned them to stay back before Schein's grenade detonated and sent the four flying backwards as the station's artificial gravity was shut off. As they attempted to escape from the breached rec room, Buck and the heavily wounded O'Day smashed into a door, killing the latter instantly. The three Spartans took shelter in an empty room until the incident was over and the gravity returned an hour later. Returning to their quarters, Buck and his team were debriefed on the events that had transpired and on Schein's defection. For almost eighteen months, largely at his request, Buck and his squad battled Covenant remnants on human colonies, including New Caracas, Gaenir Beta, and Charion VI.

Mission to Talitsa
In August of 2555, Buck participated in a mission alongside Mickey and Romeo at a United Rebel Front facility on Talitsa to recover the captured Huragok Quick to Adjust, and his human handler, Sadie Endesha. The three were sent on the mission by Dare due to their past experiences with the Huragok. On the way to the base, however, they were surrounded and forced to surrender by a large number of insurgents; it was revealed that Crespo had betrayed the team and revealed their mission to the URF. As the rebels, led by Doctor Schein, led Buck and Romeo back to their base, the latter began to insult Mickey and Schein. In response, Mickey attacked and inadvertently pushed Romeo down a hill. While the URF soldiers chased after him, Buck used the opportunity to attack Mickey and succeeded in moving the fight just out of sight of Schein, and Romeo and his pursuers. Romeo learned of Buck's situation and began to massacre the rebels. As their brawl continued, Buck eventually managed to knock Mickey unconscious with a headbutt. However, Buck was shot in the back by Schein. The doctor held him at gunpoint and attempted to use him to force Romeo to surrender, but while Schein was distracted, Buck threw his helmet at Schein's chest and knocked him to the ground. Buck grabbed Schein's rifle and smashed the shoulder stock against his face, killing him.

Taking Schein's rifle, Buck waited for Mickey to gain consciousness and watched as Romeo eliminated the rebels. After eliminating the rebels nearby, Romeo moved on to rescue Quick to Adjust and Sadie Endesha. When Mickey awoke, he asked Buck to kill him. However, Buck opted not to and the two sat down together until a dropship arrived to extract them. When they returned to the Spartan base on Mars, Buck had Mickey handed over to Jun-A266 instead of the ONI operatives that were waiting for their return, since he believed that Mickey was still a Spartan. Afterwards, Buck was congratulated by Musa for his actions on Talitsa, stating that the fact that he had not executed Mickey when products of the older SPARTAN programs like the Master Chief might have (and Jun definitely would have) proved that the SPARTAN-IV program was an amazing triumph, all because of Buck's humanity. At Buck's request, Musa reassigned Romeo and Buck to another team, with Buck serving as a member of the team rather than as its leader.

At some point after the events on Talitsa, Buck wrote the New Blood report, and was reassigned to and acted as Spartan Commander for the Spartan contingent on the ship. In 2558, Buck had become a member of Fireteam Osiris, led by Jameson Locke and also consisting of Spartans Olympia Vale and Holly Tanaka. Serving as a joint-forces liaison and advisor, Buck's current position on the fireteam is engineered by his superiors to groom him for a greater role within the Spartan branch. Fireteam Osiris was charged with carrying out a variety of complex missions for the UNSC Security Council and High Command. At some point, Buck began to assist with providing commentary to Spartans in War Games simulations aboard the.

Battle of Kamchatka
"Edward Buck"

- Jameson Locke

After several human colonies were unexpectedly attacked by mysterious Forerunner entities, Doctor Catherine Halsey contacted UNSC Infinity with information about the attacks. In response, Buck and the rest of Fireteam Osiris were tasked with rescuing Dr. Halsey from the custody of “Covenant” Supreme Commander Jul 'Mdama on the Forerunner world of Kamchatka.

After being briefed by Captain Thomas Lasky of UNSC Infinity, the Spartans were delivered to Kamchatka via D79-TC Pelican, where they discovered the Covenant engaging their former Promethean allies. Osiris exited the Pelican dropship to free fall past battling Covenant and Promethean ships, using their armor's thrusters to control their following landing. Osiris landed on a mountainside, where the Covenant and Prometheans were currently engaged in combat and the Spartans fought their way through the terrain. While Vale eliminated Covenant forces aboard a Type-57 Phantom, Buck and the rest of Osiris killed Covenant and Promethean forces on the ground. As one of the Covenant blockade runners crashed into a nearby mountain peak, Osiris regrouped and was forced to outrun the ensuring avalanche. The Spartans leaped off a cliff and slide down the mountainside, where they promptly engaged nearby Covenant forces in a valley. With 'Mdama and Halsey located in a nearby Forerunner structure, Fireteam Osiris fought their way past Covenant and Promethean forces to reach their targets' location. Although 'Mdama had a deployed to fend off the hostile forces assaulting his location, the Prometheans managed to force the walker to retreat.

As Osiris battled their way to the structure, they arrived at 'Mdama's and Halsey's position on a balcony. Once they had a clear shot, Buck killed one of 'Mdama's Zealot guards with a Z-250 lightrifle and Locke charged towards 'Mdama to begin engaging the Supreme Leader in close-quarters combat. While Locke assassinated 'Mdama, Buck, Vale, and Tanaka eliminated the rest of the Sangheili on the platform. With Halsey recovered, Osiris and the doctor returned to UNSC Infinity.

Mission to Meridian
"You know, Locke… Every other Spartan… every soldier, when they hear about this… they're gonna hate us. You know that, right?"

- Edward Buck

Upon their return to Infinity, Fireteam Osiris learned that Spartan-IIs John-117, Kelly-087, Linda-058, and Frederic-104 of Blue Team traveled to the Outer Colony of Meridian—absent without leave—to investigate smart AI Cortana's location. Osiris was tasked with embarking to the recently resettled and now independent Meridian to track down Blue Team and take them back to the UNSC. Fireteam Osiris arrived at the Meridian space elevator—Pinnacle Station—via Pelican, where they descended to the moon's surface. Osiris quickly discovered that Meridian was also under attack from Promethean constructs and the moon's settlers were desperately attempting to fend off the invaders. Osiris agreed to help defend Meridian's settlers from the Prometheans in exchange for the cooperation of the colony's de facto leader, Governor Sloan. After destroying numerous Promethean constructs that were assaulting the outpost at the base of Pinnacle Station, the Spartans traveled to Meridian Station, the lead settlement on the moon which the Prometheans were attempting to invade. However, Sloan was initially unwilling to give the Osiris access to the road that led to Meridian Station, fearing that the Prometheans would follow. However, the Spartans defeated the nearby Prometheans and Sloane eventually gave them access to the road in response. While on the way to the settlement, Osiris aided the settlers under attack at a nearby service garage upon Sloan's request. In exchange for their help, Sloan had his men give the Spartans one of the Liang Dortmund Corporation's M820 Scorpions to use against the Prometheans.

After using the Scorpion to clear out the rest of the nearby Prometheans, Vale and the rest of Osiris proceeded to Meridian Station, where they discovered that Sloan was a smart AI suffering from onset rampancy. Sloan allowed the Spartans to search the settlement for clues about Blue Team's location, leading to Osiris splitting up to see if they could learn anything from the local settlers. After learning that Blue Team's prowler was seen traveling to the nearby Apogee Station, Fireteam Osiris boarded a transport Pelican and departed for the settlement. Upon arriving at Apogee, they found the settlement under attack. Working with Meridian soldiers, Buck and the other members of Osiris cleared out the Prometheans and discovered Blue Team's abandoned prowler. Accessing the prowler's data banks, Osiris discovered that Blue Team had traveled to the mines under the settlement. After eliminating more Prometheans throughout the mines, Osiris discovered that the Meridian settlers had found a massive Forerunner structure underneath the moon's surface. As they investigated the structure, they eventually came across the Warden Eternal, an ancilla that served as the protector of the Domain and claimed his loyalty belonged to Cortana. After refusing to allow the Spartans to pursue Blue Team, Fireteam Osiris engaged the Warden and eventually destroyed him. Advancing forward, Osiris came across a Guardian in a large, cavernous chamber. While exploring the area, Vale discovered a local slipspace translocation network throughout the cavern and noticed Blue Team using it on above platforms. Following Vale, Buck and the rest of Osiris pursued Blue Team as they advanced from platform to platform utilizing the translocation network. During the chase, Locke got ahead of the rest of his fireteam and was teleported to the same platform that Blue Team was on.

As the Spartan-IIs prepared to travel through one last teleporter to reach the Guardian, Locke ordered them to stand down. The rest of Osiris was teleported to a higher platform, but John-117 ordered his own teammates to go through the portal ahead of him. When John refused to stand down and moved to follow his team, Locke attempted to detain him, leading to John disarming Locke and engaging him in hand-to-hand combat while the rest of Osiris watched nearby. John eventually gained the upper hand and used Locke's own armor-locking device against him. As John escaped through the portal and entered the Guardian, the massive construct began to activate and the floating platforms around Osiris began falling out of place and into the lava below. Freeing Locke and with retracing their steps impossible, on Buck's suggestion the four Spartans rushed back the way Blue Team had entered, traveling back to each platform via teleporter. While the rest of Osiris was just able to enter the last teleporter with little difficulty, Buck's jump was misplaced and he nearly fell off the platform, though Locke managed to return in time to help him through the teleporter just as the platform plummeted into the lava below. The Spartans were teleported to Meridian's surface, where the colony was already well into its evacuation as settlers rushed into the moon's space tether. As Osiris raced to the elevator to escape the ensuring damages that would be caused by the Guardian's activation, the construct rose out of the surface nearby. While en route to the elevator, the Spartans and the evacuating settlers were once again attacked by Prometheans. After eliminating the Prometheans near the base of the elevator, Sloan allowed Osiris to enter. Vale managed to have Sloan reveal that he was warned of the Guardian's activation by Cortana, and that he intended to be a part of the future Cortana was creating for humans and AI. Osiris destroyed the remaining Prometheans nearby and, after activating it, the fireteam began ascending the elevator. On the way to the elevator terminal, while engaging more Prometheans, the Guardian sent out a shockwave that heavy damaged the elevator. The Spartans were forced to climb the elevator as the structure slowly began to fall. Just as Osiris arrived at the platform their Pelican was on, the Guardian continued to send out more frequent shockwaves that slowed the Spartans down and caused the platform they were on to collapse. Osiris barely managed to enter the dropship and promptly left Meridian's atmosphere, as the Guardian entered slipspace and left the moon.

The Guardian of Sanghelios
"Jameson Locke"

- Edward Buck

After Fireteam Osiris returned to Infinity, Lasky ordered for the fireteam—along with Commander Palmer and Halsey—to travel to the Sangheili homeworld of Sanghelios to utilize the planet's inactivate Guardian to pursue Blue Team. The Swords of Sanghelios had Buck and the rest of Osiris deployed to the planet's surface via, where they were tasked with finding Arbiter Thel 'Vadam while he was leading the Swords of Sanghelios against the invading remnants of 'Mdama's Covenant at the Elder Council Chamber in the Nuusra territory. As Osiris engaged Covenant forces, Palmer had Mahkee 'Chava deploy two Mantises for the Spartans to utilize in clearing out the Covenant warriors at the Elder Council Chamber. Upon arriving at the chamber, Osiris battled the Covenant forces assaulting the building and fought their way inside, where they meet up with 'Vadam. With Osiris' help, the Swords of Sanghelios eliminated the Covenant forces at the Council Chamber. Moments later, 'Chava arrived in a Phantom and extracted the Arbiter and Spartans. Traveling to the Swords of Sanghelios' encampment at Nuusra, Osiris worked together with Halsey, Palmer, and 'Vadam to formulate a plan to utilize the Guardian. Osiris was tasked with locating a Forerunner Constructor at one of the Guardian's nearby support stations to allow Halsey to input commands into the construct to force it to activate the Guardian. Palmer flew Fireteam Osiris to the support station, but she was forced to drop them off just south of the facility due to the presence of a nearby Covenant Kraken. While Osiris provided ground support, the Arbiter's forces assaulted the walker from the air. The Swords of Sanghelios flight squadrons forced the Kraken into retreat, and Osiris fought their way to an ancient Sangheili temple located near the support facility. After Osiris destroyed several Prometheans that had arrived at the temple, the Kraken arrived at the structure, threatening the Spartans' mission. As the walker neared, Buck and Osiris boarded the Kraken and destroyed its power generator from within. Osiris fled that doomed walker and traveled into the support facility via stolen s. Once inside the station, Osiris retrieved a Constructor, but were promptly attacked by Promethean forces. After battling their way back to an extraction point with the Constructor, a Phantom transported them back to the Swords of Sanghelios' encampment.

With the Constructor, Halsey inputted her commands into it and the construct took off to activate the Guardian. However, the Guardian was located in the Csurdon Sea next to the city of Sunaion, the last bastion of the Covenant on Sanghelios. The Arbiter's forces regrouped and prepared to attack the city to eliminate the Covenant and give Osiris a chance to board the Guardian. Traveling to Sunaion with a group of air vehicles, the Spartans, the Arbiter, and several Swords of Sanghelios forces deployed on the ground and engaged Covenant soldiers. While the Arbiter led his forces against the Covenant directly, Osiris eliminated anti-air emplacements to allow the Arbiter's fleet to move in closer to the city. Unable to receive air support for transport to the Guardian, Osiris accessed Sunaion's undercity to travel towards the construct's location. As the Constructor activated the Guardian, more Promethean forces arrived at the battle and began engaging the Arbiter and his forces. When the Guardian began rising out of the water nearby and started to activate its shockwaves, the buildings around the Spartans began to fall apart. As the Spartans moved to safety, they encountered the Arbiter engaging Promethean forces. The five battled the onslaught of Prometheans, which were soon led by the Warden Eternal, now utilizing another physical body. After a lengthy engagement, the five defeated the Warden and the nearby Prometheans just as the Guardian prepared to leave. While the Arbiter remained behind to finish eliminating Covenant and Promethean forces, Palmer and Halsey picked up Osiris in the Pelican and flew towards the Guardian. A pursuing Covenant Banshee damaged the dropship, resulting in Buck nearly falling out of the Pelican with Locke preventing him from doing so. Palmer was able to fly close enough to the Guardian's surface to drop off Osiris just as the construct entered slipspace and left Sanghelios.

Cortana and Genesis
"Cortana"

- Edward Buck

Upon exiting slipspace, the Guardian arrived at the Forerunner world of Genesis, where all the other Guardians had traveled to at Cortana's demand. While the Spartans observed their new surroundings, the Guardian attempted to shake the Spartans off, forcing Buck and the rest of Osiris to quickly descend down the construct until they were close enough to the ground to safely jump off the Guardian. Osiris soon encountered monitor 031 Exuberant Witness, who served as caretaker of the Genesis installation. The ancilla revealed that Cortana was intending to use the Guardians to force peace across the galaxy and to wipe out those that refused, apparently trying to instill the Forerunners' Mantle of Responsibility on all species with herself and other AI—now calling themselves the Created—as its holders. Osiris resolved to regrouping with Blue Team and stopping Cortana, with the help of Exuberant Witness. As the Spartans traveled to Blue Team's position at Genesis' Gateway, they encountered Covenant forces that were inadvertently brought to Genesis with the Guardians, as well as hostile Promethean forces led by the Warden. Osiris fought their way towards the Gateway, where they were attacked by the Warden Eternal once again, though the Spartans eventually managed to defeat him. Upon arriving just outside the Gateway, Osiris came under attack from several of the Warden's bodies and his forces, as the Prometheans attempted to buy more time for Cortana to finish her plans. After a long engagement, Osiris was able to defeat their Promethean opponents and Exuberant Witness was able to provide the Spartans with access to the inside of the Gateway.

Upon entering, Osiris and Exuberant Witness encountered Blue Team. While the eight Spartans agreed to work together to stop Cortana from enacting her plans, the AI suddenly teleported Blue Team to near her position. Cortana ultimately placed Blue Team in a Cryptum with the intention of keeping them in stasis for ten thousand years while she initiated her plans. Osiris moved to free Blue Team and, upon exiting the Gateway, noticed that the Guardians were entering into slipspace to begin enforcing Cortana's new order. As the Spartans engaged Covenant and Promethean forces while on their way to the Cryptum, Cortana revealed that hundreds of AIs had pledged their allegiance to her, including Governor Sloan. Reaching the Cryptum, Osiris had to destroy several gravitational cores keeping the Cryptum in place. As Osiris came close to freeing Blue Team, Cortana began to taunt the Spartans in hopes of demoralizing them, but to no avail. After destroying the gravitational cores, Osiris activated a terminal to lower the Cryptum. However, Cortana suddenly pulled the Cryptum to the Guardian she was preparing to leave on. As Cortana prepared to leave, she disconnected herself from Genesis' systems, giving Exuberant Witness an opportunity to take full control of the planet once again. To aid the monitor, Osiris activated two nearby auxiliary power stations to help Exuberant Witness regain control of Genesis. The monitor provided the Spartans a passage to Cortana's Guardian and the Cryptum, and Osiris rushed to stop their departure, pushing past the Guardian's shockwaves. Locke managed to reach the relay terminal that gave Cortana control and destroyed it, reinstating full control of Genesis to Exuberant Witness. Cortana prepared to leave the planet aboard her Guardian with the Cryptum, but Exuberant Witness sent a fleet of Constructors to take the Cryptum from the Guardian just as it entered slipspace. Following Cortana’s departure, both Blue Team and Fireteam Osiris together fought their way through hordes of Promethean constructs to reach a D79-TC Pelican that had previously arrived on the planet via a Guardian’s Slipspace entry. Agreeing to return to Sanghelios, the joint team requested Witness’ help, who opened a Slipspace portal for them.

Regroup
Upon their arrival at Sanghelios, they deduced that surviving allies might be hiding in the region of Nuusra. Sure enough, they located the Swords of Sanghelios’ makeshift campsite in the cliffs and touched down, reuniting with Halsey, the Arbiter, and Palmer.

Reuniting Alpha-Nine and marriage
After returning to the Infinity, Buck was reunited with Dare who recruited him for a mission to learn about the Forerunner technology on Cassidy III that allowed the United Rebel Front to cloak themselves. To Buck's anger, this required breaking Mickey out of jail as Buck was still angry with his old friend for betraying him. Buck rescued Romeo from Balaho and Vergil and Sadie Endesha from a secret ONI facility on Luna before going after Mickey alone at the Spartan-IV training station where Mickey was imprisoned. Buck's anger at his old friend led to Buck blowing up at him and seriously considering leaving Mickey behind. Buck decided to shut down the station's AI Leonidas who was suspected to be compromised. Leonidas attempted to stop Buck, going so far as to declare him a rogue Spartan and threatening to kill everyone on the station if he didn't surrender. Thanks to the timely intervention of Vergil, Buck managed to shut Leonidas down and destroyed the AI's data crystal chip to keep him from being rebooted. With the occupants of the station after him due to Leonidas, Buck struggled to escape with Mickey only to receive unexpected help from Dutch and Gretchen Ketola who were training on the station. With his team reunited, Buck escaped and to his relief, was contacted by Jun who Buck had feared was dead. Buck evaded Jun's questions about his actions, but warned Jun of the possibility of a Guardian coming after the station. Jun thanked Buck for helping him regain control of the station and promised not to forget what Buck did for him. Jun acknowledged that he knew that Buck had helped Mickey to escape, but also acknowledged the circumstances surrounding it and told Buck that Mickey was his responsibility.

With his team reunited, Buck led them to Cassidy III where they witnessed Dare negotiate with Mayor Wells. Buck's knowledge of Dare's mannerisms allowed him to tell when she was lying and he continued to clash with Mickey over Mickey's betrayal. When Leonidas summoned a Guardian to the planet, Buck and Alpha-Nine helped with the evacuation and Buck and Mickey finally reached an understanding with each other. During their escape in a Condor, Buck helped Vergil conduct repairs, but almost fell out of the ship to his death. Buck was saved by his teammates, including Mickey to his surprise. Grateful to his friend, Buck agreed to help keep him out of jail for the time being at least despite knowing that Mickey could never be fully trusted again.

After returning to the Infinity, Buck met with Laskey and Palmer on the mission. To their surprise, Buck advocated for Mickey and got them to agree to allow Mickey to remain free, though all three agreed that Mickey couldn't be trusted with missions regarding the Front. While Buck admitted that he might be able to forgive Mickey, he would never forget what he had done. Buck later talked with Locke about the Mickey situation and admitted that he had blamed himself for Mickey's defection, but finally understood that it wasn't his fault. With Buck's confidence in his leadership skills restored, Buck stated that if he was asked to lead Alpha-Nine again instead of being a part of Fireteam Osiris he'd be fine with it.

Buck later joined his two teams in celebrating in the Full Moon, one of the bars aboard Infinity. Dare essentially dared Buck to marry her, knowing that he would never propose if she didn't make a move. Buck agreed and was surprised when Dare immediately began preparing to be married through an automated program on a bar tablet. When Buck asked about getting Lasky to marry them, Roland interrupted to offer to marry them instead. With Roland assuring him that such a ceremony would still be legal, Buck, who held affection for the AI due to his rejection of Cortana and the Created, agreed. Buck and Dare were then married by Roland which was witnessed by their friends from Fireteam Osiris and Alpha-Nine.

Leader of Alpha-Nine once more
Soon after Buck's honeymoon, the restored Alpha-Nine was sent on another classified mission. After all the hardships the team had gone through, they worked together better than ever much to Buck's happiness.

Personality and traits
"Bam, said the lady!"

- A recurring catchphrase used by Buck

Edward Buck is a brave soldier who consistently displays strong leadership skills and perseverance. He is also adept at de-escalating situations and hyper-focusing a team on a task, especially under great duress. Buck models a classical and robust strategy logic but also can think fast on his feet. He exemplifies a strong team ethic that includes a strong emphasis on the value of each member, even at the expense of the whole team. Decisions in the field are informed by the same wide moral framework that affects all aspects of his performance. Buck's commendable success in his early military career led to the acceptance of his application to the Orbital Drop Shock Troopers. Buck's over two decades of service at the front lines of the Human-Covenant War established him as an incredibly devoted leader and effective combatant, even among the elite ODSTs. By the time of the Battle of New Mombasa, Buck was considered to be one of the most skilled ODSTs alive, with only SPARTANs being better soldiers than him. By January 2553, he was being considered for both the SPARTAN-IV program by Musa Ghanem and the ONI covert intelligence unit, Kilo-Five, by CINCONI Margaret Parangosky. His inclusion on Kilo-Five was ultimately judged against due to his attachment to his teammates in Alpha-Nine, ethical convictions, and prioritization of personnel over objectives. After Buck helped Mickey escape from the Spartan-IV training station during a covert mission for ONI, he was evasive when contacted by Jun-A266 about his actions, but warned him of the possible threat coming. Though Jun initially threatened to court-martial Buck, he dropped his hostility after the formalities were over to express understanding for Buck's actions and thanks for his help in retaking the station from Leonidas as well as a promise to remember what Buck did for him.

Watching so many of his fellow Marines die has left Buck brash and ill-tempered, but this was not always so. When he was younger, Buck never had a particular interest in school. He did, however, love fishing on the Gold Sea with his uncle and other fishers. In his view, he felt free and believed he would be happy living life as a fisherman. However, when the Covenant attacked Harvest, he put his dreams aside to join the UNSC and aid humanity. Buck is particularly stubborn, a fact that he is aware of, having been told by his mother many times. Buck is able to always come up with a plan on the fly, an ability he believed was the reason he was in command of Alpha-Nine.

His only regret during his service is that he was not given the chance to participate in the Covenant's assault on his homeworld, Draco III, in 2545, in which many of the planet's residents were slaughtered by starving Unggoy and Kig-Yar soldiers; he only shared his remorse with his closest friends. This led to Buck forming a bloodlust against the Covenant, one which he eventually mitigated through his relationship with Veronica Dare. When ever he had spare time during his service in the SPARTAN-IV program, Buck generally kept close to Dare, or remained at a UNSC military base and socialized with the leaders of the Spartan branch.

After the disbanding of Alpha-Nine, Buck was happy to let someone else make the decisions as part of Fireteam Osiris instead of being a leader. This was because his inability to see Mickey's betrayal coming had shaken Buck's confidence in his own leadership skills and left him preferring to let others make the decisions for him. However, Buck's abilities as a leader were so valued that Captain Thomas Lasky told Buck that if he ever wanted to leave Osiris to lead his own fireteam again, Sarah Palmer would have no trouble giving him one in a heartbeat. When approached to reunite Alpha-Nine for a mission during the Created conflict, Buck was reluctant to become a leader again following his perceived failures. After being the leader of Alpha-Nine again as well as finally understanding that he wasn't at fault for Mickey's actions, Buck's confidence was restored to the point that he left Osiris to lead his old team again full time.

Relationships
"Take my advice, Rookie. You ever fall for a woman? Make sure she's got balls."

- Buck to the Rookie, referring to Dare

Buck developed a romantic relationship with Veronica Dare, an intelligence officer in Section One of the Office of Naval Intelligence. At one point, he proposed to her, but Dare remained silent, feeling that her job would force them to split. The two eventually agreed to end their relationship. The two first met on Castellaneta, a resort orbiting Saturn. Although the two enjoyed their week of shore leave together, Dare left him after Buck realized that she was a "spook". After their encounter on Sargasso, the two avoided each other for the remainder of the war, until they were forced to work together in the Battle of Mombasa. Although he thought he had buried his feelings for her, Buck's search for her during the battle made him realized that he had not gotten over her. After their time together on Mombasa reignited a spark in their relationship, the two vacationed together on Sundown.

In late 2558, after reuniting Alpha-Nine to negotiate with the United Rebel Front on Cassidy III, the two discussed their relationship and the possibility of getting married. Though Buck had proposed in the past at least a couple of times, both had agreed that it was a bad idea with their jobs and the dangers that came with them. When Buck thought he was going to fall to his death, he admitted regret for not marrying Dare when he had the chance before being saved by his teammates when Dare overrode Buck's orders to leave him behind. After returning to the, Dare proposed to Buck in the form of a dare when she realized that he would never propose first. They were subsequently married by Roland in a bar on the Infinity moments after Dare proposed, witnessed by both Fireteam Osiris and Alpha-Nine.

Buck formed close relationships with his squadmates in Alpha-Nine. One of Buck's primary reasons for not originally joining the SPARTAN-IV program was due to his unwillingness to leave his teammates behind. He developed particularly close friendships with Taylor "Dutch" Miles, Kojo "Romeo" Agu, and Michael "Mickey" Crespo, having served with them for several years. Though he sometimes lost his temper with them, Buck genuinely cared for his squad mates safety, going to far as to abandon Dare's mission in order to find them. He held himself accountable for the lives of each member of his squad. Even after joining Fireteam Osiris, Buck maintains contact with his former subordinates.

Due to Mickey's betrayal on Talitsa, Buck felt a great deal of anger and resentment towards his former friend and questioned his decision to let the man live instead of executing him. Much of this came from not just the betrayal, but the fact that he didn't see it coming and that Mickey hadn't tried to come to him with his concerns before turning traitor. When ordered to break Mickey out of prison, Buck was reluctant and outright considered just leaving Mickey behind when he actually found him. Throughout the reunited Alpha-Nine's mission, Buck was extremely hostile towards Mickey and his insurrectionist views. However, when Cassidy III came under attack by a Guardian, the two men were able to reach an understanding with each other. After Mickey risked his own life to save Buck, Buck lost much of his hostility towards him and advocated for his remaining free and stated that he might be able to forgive Mickey, but he would never forget what he did. Buck also acknowledged that Mickey could never be fully trusted again, at least with regards to the Front, but was someone they needed. Buck later admitted to Locke that much of his anger and resentment came from his belief that he should've seen Mickey's betrayal coming and he now recognized that while he was open and honest with Mickey and a good friend, Mickey didn't honor that in return.

Buck's impression of the Spartan-IIs lined up with the rest of the ODST sentiment that they are "glory hounds," but softened into having an admiration for John-117 after learning his military history and entering the SPARTAN-IV program, considering John as a "superhero." When Fireteam Osiris was assigned to hunt down Blue Team on Meridian, Buck vocally raised his concerns about hunting Blue Team, stating that everyone in the UNSC military would hate Osiris for carrying out their mission. While he grew to respect the Master Chief, he was disturbed by the relationship he and the Spartan-IIs had with Catherine Halsey, as she had a role in kidnapping, militarily enlisting, and cybernetically augmenting them since they were kids, and yet still has a motherly attitude towards them; he stated that he would not feel "clean" if he read the Spartans' psyche evaluation.

Buck developed a budding friendship with his squadmates in Fireteam Osiris as well, maintaining some levity with the high-risk situations they were trust into. Buck opened up about his relationship with Dare to Olympia Vale, stating that the two women would get along well. Compared to his professional experience with Dare, Buck has a friendly working relationship with ONI agent Jameson Locke, even cracking jokes when Locke saves him from fatal situations. When it comes to addressing his concerns about the nature of their mission, Locke is transparent in what must be done with some explanation. Buck was able to talk to Dare about his assignment to Fireteam Osiris with Locke's permission much to Dare's surprise, especially with Locke's reputation as "ONI to the bone." Buck would later state that working with any member of Fireteam Osiris was easier than working with Romeo.

Buck held a high level of respect for the Sangheili, both to the ones who were still fighting the UNSC, and the ones who have pledged themselves to the Swords of Sanghelios; he particularly held high regard toward Arbiter Thel 'Vadam, whom he credited for contributing to humanity's survival. This was best shown when he decided to avenge the death of the Arbiter's fallen warriors (whom he respectfully called "brothers") who died fighting the Covenant, simply because they were humanity's allies.

Equipment
As an Orbital Drop Shock Trooper, Edward Buck wore basic ODST armor with a CNM attached to the right side of the helmet and a combat knife on the right side of his chestplate. After joining the SPARTAN-IV program, Buck now wears the Helljumper variant of the MJOLNIR GEN2 armor, modeled after ODST armor, as well as a Gallows visor. His new armor had many similarities to his old armor as he still as his last name on his chestplate, has ammo packs on his right leg and retains his combat knife but it is now on his left side near his shoulder. There is an ODST crest near his left armpit. The left side of his chestplate bears a carving beneath his knife of an arrow-pierced heart with the letter "V" in it, referencing his relationship with Veronica Dare. As an ODST, Buck preferred using an MA5D assault rifle and M6H2 pistol in combat.

Miscellaneous

 * Canonically, Buck's blood type is O-, making him a universal blood donor, but O- is also the hardest type to match. However, in Halo: Reach, his MEDREF patch shows his blood type to be O+. This is because he has the same character model as all other ODSTs in the game, as he is not meant to be seen up close.
 * In an Easter egg in the epilogue cutscene after the credits in Halo 3: ODST, if the player looks to the left near the end of Johnson's talk with Quick to Adjust, the camera will pan over to Buck standing next to a caveman, he attempts to groom and eat off it.
 * Rarely, if the player jumps with Buck somewhere in a vehicle, he will sing the first few bars of "Dixie" in reference to The Dukes of Hazzard.
 * In the level New Alexandria in Halo: Reach, the player can follow Buck into the building after he lands, but he will disappear after a few moments.
 * When Buck requests assistence in the level New Alexandria in Halo: Reach, where he is sitting in the Falcon depends on which mission he gives.
 * If Buck states that a Phantom has his team pinned down, then he will be piloting the Falcon (with his teammates manning the guns once evacuated).
 * If Buck states that he is on a classified operation, then he will be manning one of the Falcon's guns while a normal Marine pilots the Falcon.
 * If Buck states that his team was caught in a firefight and he needs an escort to them, then Buck will be sitting in one of the passenger seats while a normal Marine pilots the Falcon.

Production notes

 * Edward Buck debuted as one of the main characters of Halo 3: ODST and is the main protagonist and narrator of the novels Halo: New Blood and Halo: Bad Blood.
 * Buck is voiced by, and his appearance is modeled on, Nathan Fillion, who also starred in Halo 3 as Gunnery Sergeant Reynolds. Fillion has described Buck as "...a bit hardened and a bit cranky."
 * Some of Buck's lines, such as "Gorram!" and "Bam, said the lady!" come from the television shows Firefly and Castle, respectively; Fillion plays the starring roles of both shows. On Firefly, Fillion acted with both Adam Baldwin and Alan Tudyk, who respectively provided the voices of Dutch and Mickey in Halo 3: ODST. Buck's middle name, Malcolm, is a probable reference to Malcolm Reynolds, Fillion's character in Firefly.
 * Travis Willingham, who portrays Frederic-104 in Halo 5: Guardians, was a stand-in for Fillion during a few mocap scenes as Fillion was unavailable at the time. However, scenes with Willingham as Buck were redone with Fillion when the actor's schedule let him three months later.
 * In Halo 3: ODST, Buck is unlocked for play in Firefight by getting the Tayari Plaza achievement. In Halo: Reach, Buck's voice can be purchased for 15,000 credits for use in Firefight mode.
 * Buck is the first playable character in the Halo series to speak during combat gameplay.
 * Buck's place as the fourth member of Fireteam Osiris was filled by Gabriel Thorne in an early phase of the development of Halo 5: Guardians; Thorne was replaced by Buck later on after Nathan Fillion agreed to reprise his role. Thorne is still shown alongside the members of Osiris in an early piece of artwork featured as the cover of The Art of Halo 5: Guardians.
 * Buck is a playable character in Halo 5: Guardians. His unique base attributes are increased melee damage, faster thruster recharge and slower stabilizer descent.
 * Due to fan popularity, Buck is one of three bonus multiplayer announcers in Halo 5: Guardians, with the other two being 031 Exuberant Witness and Yabda, all obtainable through the Voices of War Pack.

List of appearances

 * Halo 3: ODST Pre-mission Evaluation
 * Halo 3: ODST
 * Halo: Reach
 * Halo 2: Anniversary
 * Halo: New Blood
 * Hunt the Truth
 * The Hunt Begins


 * Halo 5: Guardians
 * Limited Edition dossiers
 * Halo Mythos
 * Halo: Bad Blood
 * Halo: Official Spartan Field Manual
 * Halo: Shadows of Reach