A freak accident leaves two dangerously unstable spacecraft locked together, and a horde of monsters unleashed on their passengers.
Tom Baker
as The Doctor
Lalla Ward
as Romana
David Brierly
as K9 (voice)
Lewis Fiander
as Tryst
David Daker
as Rigg
Geoffrey Bateman
as Dymond
Jennifer Lonsdale
as Della
Stephen Jenn
as Secker
Richard Barnes
as Crewman
Barry Andrews
as Stott
Geoffrey Hinsliff
as Officer Fisk
Peter Craze
as Officer Costa