The Doctor
Tom Baker
Sarah Jane Smith
Elisabeth Sladen
John Stevensen
Hubert Rees
Charles Winlett
John Gleeson
Doctor Chester
Ian Fairbairn
Major Beresford
John Acheson
Sergeant Henderson
Ray Barron
Chauffeur
Alan Chuntz
Guard Leader
David Masterman
Guard
Harry Fielder
Harrison Chase
Tony Beckley
Richard Dunbar
Kenneth Gilbert
Sir Colin Thackeray
Michael Barrington
Amelia Ducat
Sylvia Coleridge
Scorby
John Challis
Arnold Keeler/Krynoid Voice
Mark Jones
Hargreaves
Seymour Green
Derek Moberley
Michael McStay
Producer
Philip Hinchcliffe
Script Editor
Robert Holmes
Director
Douglas Camfield
Writer
Robert Banks Stewart
Music
Geoffrey Burgon