Cast
Peter Davison
The Doctor
Sarah Sutton
Nyssa
Janet Fielding
Tegan Jovanka
Mark Strickson
Vislor Turlough
Nicholas Courtney
Brigadier Alistair Gordon Lethbridge-Stewart
Valentine Dyall
The Black Guardian
David Collings
Mawdryn
Angus MacKay
Headmaster
Stephen Garlick
Ibbotson
Roger Hammond
Dr. Runciman
Sheila Gill
Matron
Peter Walmsley
Mutant
Brian Darnley
Mutant
William Hartnell
The Doctor (1) (archive footage)
Patrick Troughton
The Doctor (2) (archive footage)
