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Childhood and training
Thom was orphaned in the early years of the Human-Covenant War when the Covenant glassed his homeworld. He was identified as a potential candidate for the first class of the SPARTAN-III program at a young age and, after "volunteering" for the program, was taken to the classified world Onyx for training under Lieutenant Kurt Ambrose and SCPO Franklin Mendez in late 2532. Thom was identified by Ambrose and Mendez as one of a handful of exceptional specimens within the SPARTAN-III Alpha Company and was extracted from the group before the disastrous Operation: PROMETHEUS. He and a small number of other Spartans were given MJOLNIR Powered Assault Armor and were assigned to smaller special operations units, eventually NOBLE Team.
During the Battle of Fumirole on April 22, 2552, Thom participated in an operation put together by Lieutenant Commander Kat-B320 to destroy the CCS-class battlecruiser, Sanctity of Purification, maintaining position above a city. However, Kat, who carried the Fury tactical nuclear weapon intended to destroy the Covenant ship, was incapacitated while on her way to the objective by an enemy Banshee.
Thom was the first to arrive to where Kat was laying wounded, picking up the nuke for her and using his jetpack to fly into the battlecruiser's gravity lift. Once inside, he threw the nuke into a crowded hangar and attempted to escape the ship before it went off, without success. The nuke detonated before Thom could safely make it out, destroying the ship and killing him.
Both Commander Carter-A259 and Lt. Commander Kat took responsibility for Thom's death, unable to admit that his death was his own decision. The team's commanding officer, Colonel Urban Holland, asserted that Thom died because he chose to attack Covenant forces without waiting for backup. Thom was replaced on Noble Team by SPARTAN-B312 in July 2552, only days prior to the Fall of Reach.
Thom wore gray Mark V MJOLNIR armor and a Mark V[B] helmet with an Up-Armor attachment, and FJ/PARA knee guards. During the Covenant attack on Fumirole, he was seen with a Series 8 jetpack on his back. He was also known to use an M392 Designated Marksman Rifle.
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