Tech Chief Thom Shepard was an Engineering Technician aboard the UNSC cruiser Pillar of Autumn in 2552. He along with Tech Officer Sam Marcus unsealed the Master Chief from the Cryo-chamber at the beginning of Halo: Combat Evolved. He runs the Chief through several diagnostics and tests his MJOLNIR armor. Soon after, Captain Keyes calls the Chief to the Bridge of the ship. A Squad of Elites enter the conrol center of Cryo-B, killing Sam. He then rushes out the door where he is killed by an explosion of a conduit in the wall.