Last updated 24 March 2024


Episode 1

Series Episode Number: 265

World Premiere: Sat 21 Mar 1970 - 5:16pm BST [BBC One] (United Kingdom)
First Broadcast: Mon 13 Oct 1975 - 6:30pm CDT [WTTW 11 Chicago]
Running Time: 24 minutes 33 seconds

7.10 Million (UK)

Appreciation Index: 60 (UK)

Chart Position: 60 () (UK)

Recorded on Fri 13 Feb 1970 in Television Centre 3
Archive State: PAL 2 VT



Contact has been lost with Mars Probe 7. When contact is also lost with the recovery ship, UNIT is called in and the Doctor learns that someone is sending messages to the vessel.


Production Team hide uncredited
WriterDavid WhitakerInfo
WriterTrevor Ray (uncredited)Info
WriterMalcolm Hulke (uncredited)Info
WriterTerrance Dicks (uncredited)Info
DirectorMichael Ferguson
ProducerBarry Letts
DesignerDavid Myerscough-Jones
Script EditorTerrance Dicks
Special SoundBrian Hodgson (uncredited)
Special Sound BBC Radiophonic Workshop (uncredited)
CostumesChristine Rawlins
Make-upMarion Richards
Action by HAVOC
Visual Effects DesignerPeter Day
Film CameramanA A Englander
Film EditorDon Godden
Incidental MusicDudley Simpson
Title MusicRon Grainer
and BBC Radiophonic Workshop (uncredited)
Studio LightingGeoff Shaw (uncredited)
Studio SoundGordon Mackie (uncredited)
Technical ManagerBernard Fox (uncredited)
Vision MixerJohn Barclay (uncredited)
Grams OperatorAndy Stacey (uncredited)
Inlay OperatorAlan Gomery (uncredited)
Production AssistantNicholas John (uncredited)
Assistant Floor ManagerMargot Hayhoe (uncredited)
Floor AssistantJohn Turner (uncredited)
AssistantPauline Silcock (uncredited)
Location Make-UpTeresa Wright (uncredited)
Film SoundDoug Mawson (uncredited)
Assistant Sound RecordistMervin Broadway (uncredited)
Film Camera AssistantRoger Twyman (uncredited)
Film Camera AssistantNigel Walters (uncredited)
Videotape EditorJeff Higgs (uncredited)
Videotape EditorRon Bowman (uncredited)
Design AssistantDick Coles (uncredited)
Production SecretarySandra Brenholz (uncredited)
Director's AssistantKate Nemet (uncredited)
Artist BookingBarbara Buchanan (uncredited)
DresserArthur Funge (uncredited)
DresserJean Holder (uncredited)
Title Music ArrangerDelia Derbyshire (uncredited)
Title SequenceBernard Lodge (uncredited)