The Krotons - Production

Production

Working titles for this story included The Trap and The Space Trap. Holmes had originally submitted The Trap to the BBC as a stand-alone science-fiction serial in 1965. Head of Serials Shaun Sutton rejected the serial as being not the kind of thing the BBC was interested in making at the time, but suggested the writer pitch it to the Doctor Who production office as an idea for that series. Holmes did so, and although story editor Donald Tosh was interested, the scripts went no further at the time. Some years later, assistant script editor Terrance Dicks found the story in the production office files when clearing a backlog, and decided to develop it with Holmes as a personal project, in case other scripts fell through. When the latter event occurred, Dick Sharples script Prison in Space a comedic dystopian tale where females rule with dollybird guards proved unworkable, Dicks was able to present the serial to his superiors as a ready production. Director David Maloney agreed the serial was viable, and it went before the cameras very quickly as an emergency replacement.

Robert La'Bassiere is actually a pseudonym for Robert Grant, who requested that he be credited under this name for his appearance as one of the Krotons. Scenes set on the planet's surface were filmed at the Tank Quarry and West of England Quarry on the Malvern Hills.