Guard 1 (The Enemy of the World)

A guard came with Donald Bruce to Giles Kent's caravan to arrest Kent, Astrid Ferrier and the Second Doctor in 2018. When the Doctor made Bruce take him to the Kanowa research station, Bruce told the guard to guard the caravan.

When Astrid broke a window and pretended Kent was dead, he bent over the "body" to exam it, Astrid slipped out. He followed her, allowing Kent to escape to the station. (TV: The Enemy of the World)