Editing Fireteam Osiris

{{Status|Canon}}

{{Disambig header|the Spartan-IV team|other uses|Osiris (disambiguation)}}

|image= [[File:Osiris.png|100px]]<br/>Fireteam emblem

[[File:H5G-Rad.png|300px]]<br/>Fireteam Osiris avoids a crashing [[Sangheili]] [[Hekar Taa-pattern blockade runner|blockade runner]] at [[Kamchatka]].

|branch=[[Spartan Operations|Spartan]]{{Ref/Reuse|universe}}

|size=3 (as of [[2558|November 2558]])

|commanders=[[Jameson Locke]]{{Ref/Reuse|universe}}

'''Fireteam Osiris''' is a specialized combat and intelligence gathering team of [[SPARTAN-IV program|Spartan-IV supersoldiers]] of the [[Spartan Operations|Spartan branch]].{{Ref/Reuse|universe}}<ref name="GI">'''Game Informer''', ''July 2015 issue''</ref> The team carries out complicated and classified missions for the [[Unified Earth Government]] and its [[United Nations Space Command]], typically dealing with issues that are deemed hard to control by the [[UNSC High Command]].<ref>'''Halo: New Blood''', ''Coda''</ref> Fireteam Osiris' activities are classified at the highest levels of government.{{Ref/Reuse|universe}}

Fireteam Osiris is composed of four of the most prominent and effective personnel from throughout the different branches of the [[United Nations Space Command]]. Osiris' members were selected based on their skills, with the desired outcome being that each team member's skills would mitigate another's deficiencies. The [[fireteam]]'s balanced skillset and impressive success rates cause them to be commonly deployed in extremely sensitive and complex missions.{{Ref/Reuse|universe}}

*Spartan [[Jameson Locke]] – Team leader; former acquisitions specialist for the [[Office of Naval Intelligence]].{{Ref/Reuse|universe}}

*Spartan [[Holly Tanaka]] – A highly skilled engineer; former member of the [[UNSC Army]] Corps of Engineering.{{Ref/Reuse|universe}}

*Spartan [[Edward Buck]] – A former [[Orbital Drop Shock Trooper]],{{Ref/Reuse|universe}} and former advisor and mentor of the team.<ref>[http://news.microsoft.com/stories/halo5/ '''Microsoft''': ''Stories - Halo 5'']</ref> After the beginning of the [[Created conflict]], Buck was sent by ONI on a secret mission to [[Cassidy III]] that led him to reform his old team of [[Alpha-Nine]]. Following the mission, Buck chose to leave Osiris to lead Alpha-Nine again on a permanent basis.<ref name="Bad Blood">'''[[Halo: Bad Blood]]'''</ref>

After several human colonies were unexpectedly attacked by mysterious Forerunner entities, Doctor [[Catherine Halsey]] contacted {{UNSCShip|Infinity}} with information about the attacks. In response, Fireteam Osiris was tasked with rescuing Dr. Halsey from the custody of [[Jul 'Mdama's Covenant faction|Covenant]] [[Supreme Commander|Supreme Commander]] [[Jul 'Mdama]] on the [[Forerunner]] world of [[Kamchatka]].{{Ref/Reuse|osiris}}

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 [[Battle of Kamchatka|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 {{Pattern|Mikpramu|Phantom}}, Locke and the rest of Osiris battled numerous Covenant and Promethean forces on the ground. As one of the [[Sangheili blockade runner|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 {{Pattern|Shuul'se|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. While Tanaka, Vale, and Buck engaged 'Mdama's [[Sangheili Zealot|Zealot]] guards, Locke charged towards 'Mdama and engaged the Supreme Commander in close-quarters combat. After a brief fight, Locke managed to assassinate 'Mdama, and Tanaka, Vale, and Buck quickly eliminated the remaining Sangheili soldiers on the platform. With Halsey recovered, Osiris and the doctor returned to UNSC ''Infinity''.{{Ref/Reuse|osiris}}

{{Quote|no=two|q1=Cortana's our concern now, sir.|Locke|q2=Like hell she is.|The Master Chief|Spartan Locke and the Chief arguing{{Ref/Reuse|unconfirmed}}}}

Upon their return to ''Infinity'', Fireteam Osiris learned that [[SPARTAN-II program|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.{{Ref/Reuse|glassed}} To prepare for the mission, Locke tasked [[Unidentified AI|an AI]] to identify weaknesses in Spartan-IIs and the [[MJOLNIR Mark VI]] and acquired an [[Armor restraint|armor-locking device]] that could short circuit their armor's systems.<ref>'''[[Hunt the Truth]]''', ''[[Hunt the Signal]]''</ref> Fireteam Osiris arrived at [[Pinnacle Station]]—the Meridian [[space elevator]]—via Pelican, where they descended to the [[moon]]'s surface. Osiris quickly discovered that the world was also under attack from Promethean constructs, with Meridian's settlers desperately attempting to fend off the invaders. In exchange for colony leader [[Governor Sloan]]'s cooperation, Osiris agreed to help defend Meridian from the Prometheans. After destroying the Prometheans that were assaulting the outpost at the space elevator's base, the Spartans began travelling to [[Meridian Station]], the lead settlement on the moon which the Prometheans were attempting to invade. However, Sloan was reluctant to give Osiris access to the road leading to the settlement, fearing that the Prometheans would follow. However, after Osiris eliminated the surrounding Prometheans, Sloan allowed the Spartans access to the road. At Sloan's request, Osiris aided several settlers under attack at a nearby service garage and Sloan ordered his men to give the Spartans one of the [[Liang Dortmund Corporation]]'s [[M820 Scorpion]]s to use against the Prometheans in exchange for their help.<ref name="glassed">'''Halo 5: Guardians''', campaign level ''[[Glassed]]''</ref>

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, as 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 restraint 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. Fireteam Osiris was just able to enter the last teleporter as its platform plummeted towards the lava, with Locke assisting Buck through the portal when the latter had nearly fallen off the platform.{{Ref/Reuse|unconfirmed}} The Spartans were teleported back to Meridian's surface, where they discovered that the colony was already well into its evacuation as settlers rushed into the moon's space elevator. As Osiris raced to the elevator to escape the ensuring damage that would be caused by the Guardian's activation, the construct rose out of the surface nearby. After fighting their way to the base of the elevator, Sloan allowed Osiris to enter. Sloan then revealed 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 AIs. Osiris destroyed the remaining Prometheans nearby and, after activating it, the fireteam began ascending the space tether. 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, with Locke having to use his armor thrusters to board the Pelican as it fell from the platform. Once Locke was aboard, the Spartans left Meridian's atmosphere as the Guardian entered slipspace and left the moon.<ref name="evacuation">'''Halo 5: Guardians''', campaign level ''[[Evacuation]]''</ref>

{{Quote|no=two|q1=If we miss this Guardian, what's Plan B for catching up to Chief?|Buck|q2=This is Plan B. It's the only Guardian that we know of.|Locke|Members of Osiris discussing mission{{Ref/Reuse|sunaion}}}}

After Fireteam Osiris returned to ''Infinity'', Lasky ordered for the fireteam—along with Commander [[Sarah Palmer]] and Halsey—to travel to the Sangheili homeworld of [[Sanghelios]] to utilize the planet's inactive Guardian to pursue Blue Team. Vale and the rest of Osiris were taken to the planet's surface via {{Pattern|Kmiro'sish|Lich}}, where they were tasked with finding Arbiter Thel 'Vadam while he was leading the Swords of Sanghelios against the [[Sanghelios global war|invading]] remnants of 'Mdama's Covenant at the [[Elder Council Chamber]] in [[Nuusra]]. As Osiris engaged Covenant forces, Palmer had [[Mahkee 'Chava]] deploy two [[HRUNTING/YGGDRASIL Mark IX Mantis|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.<ref name="sos">'''[[Halo 5: Guardians]]''', campaign level ''[[Swords of Sanghelios (level)|Swords of Sanghelios]]''</ref> 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. 'Vadam, recognizing Locke as the ONI agent that had planned to assassinate him in the Covenant War, was initially reluctant to move his forces to assist the Spartans. However, when Cortana briefly shorted out all electronics at the encampment, 'Vadam agreed to work with Locke. 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.<ref name="alliance">'''Halo 5: Guardians''', campaign level ''[[Alliance]]''</ref> Palmer flew Fireteam Osiris to the support station, but was forced to drop them off just south of the facility due to the presence of a Covenant Kraken nearby. While the Spartans provided ground support, the Swords of Sanghelios assaulted the walker from the air. While the Arbiter's flight squadrons forced the Kraken into retreat, Osiris fought their way to an ancient Sangheili temple located near the support facility. After defeating several Prometheans at the temple, the Kraken arrived at the temple, threatening Osiris' mission. As the walker neared, the Spartans boarded the Kraken and destroyed its power generator from within. Osiris fled that doomed walker and traveled into the support facility via stolen {{Pattern|D'nomlhe|Banshee}}s. Once inside the station, Osiris retrieved a Constructor, but were 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.<ref name="enemy lines">'''Halo 5: Guardians''', campaign level ''[[Enemy Lines]]''</ref>

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.<ref name="before the storm">'''Halo 5: Guardians''', campaign level ''[[Before the Storm]]''</ref> Traveling to Sunaion with a squadron of air vehicles, Fireteam Osiris, Arbiter 'Vadam, and several Swords of Sanghelios forces were deployed to Sunaion and [[Battle of Sunaion|engaged]] Covenant soldiers throughout. While the Arbiter led his forces against the Covenant directly, Osiris destroyed Covenant [[Upisa'weri-pattern Shrike|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 to its location. When the Constructor activated the Guardian, Promethean forces arrived at the battle and began engaging the Spartans, as well as the Arbiter and his forces. When the Guardian began rising out of the sea nearby and started to activate its shockwaves, the buildings around the Spartans were ripped apart. As the Spartans moved to safety, they regrouped with the Arbiter as he was 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 destroyed 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 Banshee damaged the dropship, though Palmer was still able to drop Osiris off on the Guardian's surface just as it entered slipspace and left Sanghelios.<ref name="sunaion">'''Halo 5: Guardians''', campaign level [[Battle of Sunaion (level)|Battle of Sunaion]]</ref>

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.{{Ref/Reuse|genesis}} 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.<ref name="breaking">'''Halo 5: Guardians''', campaign level ''[[The Breaking]]''</ref> Osiris moved to free Blue Team and, upon exiting the Gateway, witnessed the numerous Guardians entering 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 began to disconnect 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 route to Cortana's Guardian and the Cryptum, and Osiris rushed to stop their departure, pushing past the Guardian's powerful shockwaves. Locke managed to reach the relay terminal that gave Cortana control and destroyed it, reinstating full control of Genesis to Exuberant Witness. As Vale came to Locke's aid, 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, freeing Blue Team. Following Cortana’s departure, both Blue Team and Fireteam Osiris together fought their way through hordes of Promethean constructs to reach [[India 127|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.<ref name="Halo: Bad Blood">''[[Halo: Bad Blood]]''</ref><ref name="ReferenceA">'''Halo 5: Guardians''', campaign level, ''[[Guardians]]''</ref>

Upon their arrival at Sanghelios, now mostly in the dark due to the Guardian attack at Sunaion, they correctly deduced they’d find their allies near Nuusra. Sure enough, they located the Swords of Sanghelios’ [[Sangheili hut|makeshift campsite]] in the cliffs and touched down, reuniting with Halsey, the Arbiter, and Palmer.{{Ref/Reuse|Halo: Bad Blood}}{{Ref/Reuse|ReferenceA}}

Soon afterwards, Buck was recruited to lead a secret ONI mission to contact the [[United Rebel Front]] on [[Cassidy III]] in order to learn more about the Forerunner technology cloaking their colony. Buck reformed his old team of [[Alpha-Nine]] for the mission while the rest of Fireteam Osiris, even Locke, were kept out of the loop on Buck's secret mission. Having regained his confidence in his leadership skills after the mission, Buck chose to leave Osiris to lead Alpha-Nine again on a permanent basis. After Buck's return, he found Osiris in the ''Infinity's'' Full Moon bar and they joked around together about what had happened since Buck was gone. When Buck and Captain [[Veronica Dare]] were married by [[Roland]] shortly after their return from the mission, both Alpha-Nine and Fireteam Osiris were in attendance.{{Ref/Reuse|Bad Blood}}

File:H5 Concept OsirisLineup.jpg|Concept art of Fireteam Osiris for ''[[Halo 5: Guardians]].''

**''[[Halo 5: Guardians Limited Edition dossiers|Limited Edition dossiers]]''