Last updated 24 March 2024


Episode Three

Series Episode Number: 320

World Premiere: Sat 22 Apr 1972 - 5:50pm BST [BBC One] (United Kingdom)
First Broadcast: Wed 1 Oct 1975 - 6:30pm CDT [WTTW 11 Chicago]
Running Time: 24 minutes 32 seconds

7.90 Million (UK)


Chart Position: 36 () (UK)

Recorded on Mon 13 Mar 1972 in TC8
Archive State: PAL 2 VT



Ky opens the message box but cannot understand the ancient carved tablets inside. The Marshal seals the Doctor and his friends in the caves and prepares to gas them to death.


Production Team hide uncredited
WriterBob Baker
WriterDave Martin
DirectorChristopher Barry
ProducerBarry Letts
DesignerJeremy Bear
Script EditorTerrance Dicks
Visual Effects DesignerJohn Horton
Film CameramanFred Hamilton
Film SoundDick Manton
Film EditorDave King
Special SoundBrian Hodgson
Incidental MusicTristram Cary
Title MusicRon Grainer
Title Music BBC Radiophonic Workshop
Studio LightingFrank Cresswell (uncredited)
Studio SoundTony Millier (uncredited)
CostumesJames Acheson (uncredited)
Make-upJoan Barrett (uncredited)
Fight ArrangerTerry Walsh (uncredited)
Production AssistantFiona Cumming (uncredited)
Assistant Floor ManagerSue Hedden (uncredited)
Title Music ArrangerDelia Derbyshire (uncredited)
Title SequenceBernard Lodge (uncredited)
AssistantJoan Elliott (uncredited)
Floor AssistantPhillip Hall (uncredited)
Grams OperatorGordon Phillipson (uncredited)
Vision MixerMichael Turner (uncredited)
Technical Manager(TM2)Clive Leighton (uncredited)