Simon Oates as Dr. Joe Burke

Zena Marshall as Sandy Lund

Charles Hawtrey as Joshua Yellowlees

Patricia Hayes as Mrs. Jones

Stanley Meadows as Ben Keller

Max Adrian as Dr. Henry Shore

Frank Barry as Burke (as a child)

Leonard Cracknell as Nick

André Maranne as Gendarme

Frank Forsyth as Uncle

Robert Jewell as Robot Operator

Richard Carpenter as Danny