Guest Stars Lynda Bellingham as The Inquisitor Michael Jayston as The Valeyard Honor Blackman as Professor Lasky Yolande Palfrey as Janet Leon Davis as Ortezo Michael Craig as Commodore Travers Denys Hawthorne as Rudge Arthur Hewlett as Kimber Malcolm Tierney as Doland Sam Howard as Azta David Allister as Bruchner Tony Scoggo as Grenville Richard Bonehill as Hyperion III Officer Hugh Beverton as Guard Tony Scoggo as Enzu Uncredited Robert Goodman as Hyperion III Officer Robert Goodman as Loader