At Space Observatory 1, Matt and Dr. Stamp work on a new Ultrascope space probe. However, the people of the planet the probe is sent to observe don't take too kindly to being watched and kidnap the scientists.
Gerry Anderson
Robert the Robot (voice) (uncredited)
David Graham
Lieutenant Ninety (voice)
Sylvia Anderson
Doctor Venus (voice)
Paul Maxwell
Colonel Steve Zodiac (voice)
John Bluthal
Commander Wilbur Zero (voice)