Jon Pertwee
The Doctor
Caroline John
Liz Shaw / Section Leader Elizabeth Shaw
Nicholas Courtney
Brigadier Lethbridge-Stewart / Brigade Leader Lethbridge-Stewart
John Levene
Sergeant Benton / Platoon Under Leader Benton
Olaf Pooley
Professor Stahlman / Director Stahlman
Christopher Benjamin
Sir Keith Gold
Sheila Dunn
Petra Williams / Dr Petra Williams
Derek Newark
Greg Sutton
