Lester

Lester was a member of the Nerva Beacon crew. He, Commander Stevenson and Kellman were the last survivors of the plague affecting the station.

When the Cybermen captured him, they forced him to carry Cyberbombs deep inside Voga on a suicide mission, but he was rescued and helped the Fourth Doctor defeat them. When the Doctor and Harry Sullivan were running away from some Cybermen, Lester sacrificed his life so that they could get away. When the Doctor's plan to suffocate their chest cavities by plugging them up with gold did not work and the Cybermen overpowered him and Harry, Lester leapt down from a rock ledge, catching the Cybermen by surprise. He immediately released his Cyberbomb harness, setting off a fail-safe in the event the bomb was detached from him before it reached the core of Voga. Instead of exploding at full power, a secondary explosion went off, killing the Cybermen, but also disintegrating him. (TV: Revenge of the Cybermen)