Kert Gantry was a Space Security Agent. He was posted with another agent, Bret Vyon, on a mission to the planet Kembel to investigate suspicious activity by Mavic Chen, Guardian of the Solar System. SSS agent Marc Cory had already visited the planet and been exterminated by Daleks.
When he was injured in a crash and pursued by Daleks, Gantry told Vyon to complete his mission while he held off the Daleks. Unable to stop them, he was killed shortly after. (TV: The Daleks' Master Plan)