Dr C. Evans was the chief doctor on the Moonbase. He was the first victim of the Cybermen's virus. He died in the medical bay and warned the Second Doctor and Polly Wright about "the silver hand". However, because he had been converted, the Cybermen were able to control him. After rendering Sam unconscious, they sent him to the control room to work the Gravitron's controls. He managed to sneak into the control room when everyone's attention was elsewhere, attacked Benson, who was working at the controls, and took over. He was stopped when the Cybermen shot a hole in the Moonbase, resulting in a drop in the oxygen level. (TV: The Moonbase)