All Cast
Colin Baker
The Doctor
Bonnie Langford
Mel Bush
Michael Jayston
The Valeyard
Lynda Bellingham
The Inquisitor
Honor Blackman
Professor Sarah Lasky
Michael Craig
Commodore Travers
Denys Hawthorne
Rudge
Yolande Palfrey
Janet
Malcolm Tierney
Doland
David Allister
Bruchner
Tony Scoggo
Grenville
Arthur Hewlett
Kimber
Simon Slater
Edwardes
Sam Howard
Atza
Leon Davis
Ortezo
Hugh Beverton
First Guard
Barbara Ward
Mutant / Ruth Baxter
Mike Mungarvan
Duty Officer
Martin Weedon
Second Guard
Peppi Borza
First Vervoid