Cast 18

1. 

   Tom Baker

   The Doctor

2. 

   Elisabeth Sladen

   Sarah Jane Smith

3. 

   Tony Beckley

   Harrison Chase

4. Kenneth Gilbert

   Richard Dunbar

5. Michael Barrington

   Sir Colin Thackeray

6. Sylvia Coleridge

   Amelia Ducat

7. 

   John Challis

   Scorby

8. 

   Mark Jones

   Arnold Keeler/Krynoid Voice

9. Seymour Green

   Hargreaves

10. Michael McStay

    Derek Moberley

11. Hubert Rees

    John Stevensen

12. John Gleeson

    Charles Winlett

13. Ian Fairbairn

    Doctor Chester

14. John Acheson

    Major Beresford

15. Ray Barron

    Sergeant Henderson

16. 

    Alan Chuntz

    Chauffeur

17. David Masterman

    Guard Leader

18. Harry Fielder

    Guard

Crew 5