Last updated 24 March 2024


Part One

Series Episode Number: 518

World Premiere: Sat 24 Nov 1979 - 6:01pm GMT [BBC One] (United Kingdom)
First Broadcast: Sun 1 Nov 1981 - 11:00pm CST [WTTW 11 Chicago]
Running Time: 24 minutes 17 seconds

8.70 Million (UK)


Chart Position: 41 () (UK)

Recorded on Sun 12 Aug 1979 in Television Centre 6



A terrible hyperspace accident results in two starships becoming locked together. The Doctor arrives and discovers that the incident may have also released a deadly menace.


Production Team hide uncredited
WriterBob Baker
DirectorAlan Bromly
ProducerGraham Williams
DesignerRoger Cann
Script EditorDouglas Adams
Costume DesignerRupert Jarvis
Make-up ArtistJoan Stribling
Visual Effects DesignerColin Mapson
Video EffectsA J Mitchell
Vision MixerNigel Finnis
Videotape EditorRod Waldron
Studio LightingWarwick Fielding
Studio SoundAnthony Philpott
Technical ManagerTerry Brett
Senior CameramanPeter Hider
Production AssistantCarolyn Montagu
Production Unit ManagerJohn Nathan-Turner
Director's AssistantMonica Rodger
Assistant Floor ManagerVal McCrimmon
Incidental MusicDudley Simpson
Special SoundDick Mills
Floor AssistantAlison Barnett (uncredited)
Grams OperatorAndrew Hunter (uncredited)
Make-Up AssistantElizabeth Hardiment (uncredited)
Design AssistantCarol Smith (uncredited)
Prop BuyerRobert Fleming (uncredited)
Show Working SupervisorChick Hetherington (uncredited)
K9 OperatorSteve Cambden (uncredited)
Title MusicRon Grainer (uncredited)
Title Music BBC Radiophonic Workshop (uncredited)
Title Music ArrangerDelia Derbyshire (uncredited)
Title SequenceBernard Lodge (uncredited)