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-096 to Edward Buck, commemorating him for sparing Michael Crespo

Spartan Edward "Eddie" 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. He was regarded as an extremely skilled Marine and by the Battle of Earth, was the leader of a small team, 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 became a SPARTAN-IV and eventually joined Fireteam Osiris, led by Jameson Locke.

Early life
Edward 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. He served in many battles during the Human-Covenant War, including the Harvest campaign in 2531. During the campaign, Buck and his unit were posted at the ruins of the capital city of Utgard and he was commended for his actions during the Liberation of Harvest. He continued to serve on the front lines for the following two decades.

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 a transfer for the Orbital Drop Shock Troopers immediately afterwards; his request was granted three weeks later, on February 27. 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. Although the two parted on rough terms, at some point they reconciled and Buck even asked her to marry him, though Dare unfortunately remained silent, 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 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 vocally voiced his disapproval of the mission, as he was reluctant to allow another ODST squad 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 by 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 had 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
Buck was 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 23rd, 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 Earth
During the early stages of Battle of Earth in October 2552, Buck's squad was part of the 105th Shock Troops Division that was to be inserted onto the Prophet of Regret's flagship, Solemn Penance, which was stationed over the city of New Mombasa. 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. During the drop, Dare ordered the squad to adjust their SOEIVs trajectory away from the assault carrier. Immediately after this, 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 the Rookie, 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 steal a Phantom dropship to escape the city, killing 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, The Rookie, 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 the Rookie 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 the Rookie 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. When the first carrier started 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 The Rookie 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.

Buck and his squad guarded Vergil at an ONI orbital facility for the following weeks. A 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 ensured, 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-Five 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. 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. With his largest concerns alleviated, Buck 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 witnessed medics carrying away the mutilated body of Hideo Wakahisa, a Spartan that Buck had become acquainted with. Seconds 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. 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 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. 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 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.

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, Tanaka 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 Kraken 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 Commander 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 Fred-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 a hand-to-hand combat fight between the two 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, the four Spartans rushed back the way Blue Team came by 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 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 Type-56 Lich, 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 Type-54 Banshees. 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. Once Blue Team was freed from the Cryptum, the group traveled back to Sanghelios to rendezvous with the Arbiter, Palmer, and Halsey to discuss their next move now that Cortana and other AIs were commanding numerous Guardians throughout the galaxy to enforce the Mantle of Responsibility.

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. His commendable success in his early military career led to the acceptance of his application to the Orbital Drop Shock Troopers. Buck's two-decade 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. 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.

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.

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.

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. 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.

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.

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."

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 the ODST armor, as well as a Gallows visor. 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. He still retains his combat knife on his chestplate but it is now on his left side near his shoulder. There is an ODST crest near his left armpit. Buck typically uses an MA5D assault rifle and M6H2 pistol in combat, though he also owns a powerful, customized pistol.

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, 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.

Production notes

 * 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.
 * 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 character in the Halo series to speak while being controlled by the player.
 * 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 and faster thruster recharge and slower stabilizer descent.

List of appearances

 * ONI Candidate Assessment Program V5.02A
 * Halo 3: ODST
 * Halo: Reach
 * Halo 2: Anniversary
 * Halo: New Blood
 * Hunt the Truth
 * The Hunt Begins
 * Halo 5: Guardians
 * Limited Edition
 * Halo Mythos