|Doctor Who and the Daleks in the Seven Keys to Doomsday|
|Doctor:||Fourth Doctor (The Seven Keys to Doomsday)|
The Doctor and his two newest companions, Jenny and Jimmy, prevent the Daleks and their crab-like slaves, the Clawrantulars, finding the seven crystals of Karn which would enable them to control all life in the universe.
- The Doctor - Trevor Martin
- Jenny - Wendy Padbury
- Jimmy - James Matthews
- Jedak - Ian Ruskin
- Tara - Patsy Dermott
- Garm - Anthony Garner
- Master of Karn - Simon Jones
- Marco - Robin Browne
- Clawrantulars - Peter Jolley, Mo Kiki, Peter Whitting
- Dalek Emperor - Jacquie Dubin
- Dalek voices - Peter Jolley
- Writer - Terrance Dicks
- Designer - John Napier
- Director - Mick Hughes
- Sound - Philip Clifford
- Production Supervisor - Trevor Mitchell
- Production Coordinator from the BBC - Barry Letts
- Fight Arranger - Mo Kiki
- Monster Coordination - James Acheson
to be added
- The play would open with screens showing Jon Pertwee's face changing into Trevor Martin's, followed by Martin entering dressed as the Third Doctor, apparently having only regenerated. Jenny and Jimmy would rush from the audience to help him, then become his companions for the adventure.
- The original conception had the Third Doctor as the protagonist.
- The main setting for this stage play was the planet Karn; Terrence Dicks reused the name of this planet in TV: The Brain of Morbius.
- The play has been recreated by Big Finish Productions as an audio drama. Trevor Martin reprises his role as the alternative Fourth Doctor.
- In 2008, Big Finish Productions mounted a new audio version of the play for release on CD, entitled Seven Keys to Doomsday.