Fireteam Osiris

"We are the shield between humankind and danger."

- Spartan Jameson Locke

Fireteam Osiris is a specialized combat and intelligence gathering team of Spartan-IV supersoldiers of the Spartan branch. The team carries out complicated 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. Fireteam Osiris' activities are classified at the highest levels of government.

History
After John-117 went AWOL along with his old Spartan-II unit, Blue Team, Jameson Locke recruited a team of Spartan-IV operatives with the task of recovering the Master Chief and Blue Team. The team was fitted with cutting-edge technology (including the Artemis Tracking System) to help them track down Blue Team.

During their quest to find Blue Team, Fireteam Osiris engaged the forces of Jul 'Mdama's Covenant faction on Kamchatka and participated in a joint mission with the Swords of Sanghelios in Sunaion.

Members
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 causes them to be commonly deployed in extremely sensitive and complex missions.
 * Jameson Locke – Team leader; former acquisitions specialist for the Office of Naval Intelligence.
 * Olympia Vale – Former UNSC Navy intelligence officer and xenoanthropologist.
 * Holly Tanaka – A highly skilled engineer; former member of the UNSC Army Corps of Engineering.
 * Edward Buck – A former Orbital Drop Shock Trooper.

Trivia
Osiris was an Egyptian god of the afterlife, the underworld, and the dead.

Production notes

 * Fireteam Osiris will be featured in Halo 5: Guardians. They will accompany Locke throughout the campaign and accept commands from the player. Buck, Tanaka, and Vale will also be playable in cooperative play, each with a specialized default loadout. The team will have access to the Artemis Tracking System which can highlight alternate routes as well as various items of interest.
 * 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.

List of appearances

 * Halo 2: Anniversary
 * Hunt the Truth
 * The Hunt Begins
 * Halo 5: Guardians