On screen
Cast
28 credited performers
Tom Baker
The Doctor
Elisabeth Sladen
Sarah Jane Smith
Tony Beckley
Harrison Chase
Artwork unavailable
Kenneth Gilbert
Richard Dunbar
Artwork unavailable
Michael Barrington
Sir Colin Thackeray
Artwork unavailable
Sylvia Coleridge
Amelia Ducat
John Challis
Scorby
Mark Jones
Arnold Keeler / Krynoid (voice)
Artwork unavailable
Seymour Green
Hargreaves
Artwork unavailable
Michael McStay
Derek Moberley
Artwork unavailable
Hubert Rees
John Stevensen
Artwork unavailable
John Gleeson
Charles Winlett
Artwork unavailable
Ian Fairbairn
Doctor Chester
Artwork unavailable
John Acheson
Major Beresford
Artwork unavailable
Ray Barron
Sergeant Henderson
Alan Chuntz
Chauffeur
Artwork unavailable
David Masterman
Guard Leader
Artwork unavailable
Harry Fielder
Guard
Artwork unavailable
Pat Gorman
Guard
Artwork unavailable
Ian Elliott
Guard
Artwork unavailable
Keith Ashley
Sir Colin's Aide
Artwork unavailable
Ronald Gough
Marine
Artwork unavailable
Patrick Milner
Marine
Artwork unavailable
Barry Summerford
UNIT Soldier
Artwork unavailable
Tony Snell
UNIT Soldier
Artwork unavailable
Patrick Ginter
UNIT Soldier
Artwork unavailable
Rowland Geall
UNIT Soldier
Artwork unavailable
Derek Wayland
UNIT Soldier