At some point during the Human-Covenant War, Staff Sergeant K. Stark of the 105th MEU's 19th Battalion, an acquaintance or relative of Tarkov, was killed in action. Tarkov attended Stark's funeral and afterward volunteered to be an Orbital Drop Shock Trooper. He then went through a series of brutal training exercises, including live ammunition combat crawls through mud, to prepare him for combat against the Covenant Empire in the same battalion in which Stark had served.
During one of his first battles, he dropped onto an unknown planet among other members of his battalion to engage Covenant forces. Several lances of Jiralhanae soldiers were present at the landing zone, with multiple Banshees providing close air support.
One Brute Minor struck Tarkov while he was moving up the line, knocking off his helmet and inflicting deep gashes in his face, and throwing him into a puddle. As the Brute was approaching the helpless Marine, who was firing his pistol at the Brute to no avail, a severely damaged Banshee crashed into his back, killing the Brute and saving Tarkov's life.
Years later, Tarkov, now a battle-hardened veteran whose gashes had turned into scars, led four other ODSTs in a field burial for a dead comrade. As plasma fire erupted and artillery detonated in the distance, the ODSTs put on their helmets and moved out.
- We Are ODST (First appearance)