| Episode | Credits | Transcript |
Cast[]
- Martin Landau as Commander John Koenig
- Barbara Bain as Dr. Helena Russell
- Catherine Schell as Maya
- Tony Anholt as Tony Verdeschi
- Nick Tate as Alan Carter
- Zienia Merton as Sandra Benes
- Brian Blessed as Mentor
- Anouska Hempel as Annette Fraser
- John Hug as Bill Fraser
- Gerard Paquis as Lew Picard
- Peter Porteous as Petrov
- Nick Brimble as Ray Torens
- Anton Phillips as Dr. Mathias
Uncredited[]
- Sarah Bullen as Operative Kate Bullen
- George Lane Cooper and Alf Joint as Overseers
- Jenny Cresswell as Receptionist / Operative
- John Dixon and Neil McCaul as Aliens in cave
- Reuben Martin as Gorilla
- Nina Mitchen as Alphan
- Geoffrey Moon as Short alien in cave
- Robert Reeves as Peter Reeves
- Pam Rose as Command Center Operative
- Roy Stewart as Tall Alien in Cave
Crew[]
- Directed by Charles Crichton
- Written by Johnny Byrne
- Produced by Gerry Anderson (Producer), Fred Freiberger (Producer) F. Sherwin Green (Associate producer)
- Music by Derek Wadsworth
- Cinematography by Frank Watts
- Film Editing by Mike Campbell
- Casting by Lesley De Pettit (Credited as Lesley de Pettitt)
- Production Design by Keith Wilson
- Costume Design by Emma Porteous
- Hairdresser: Patrick Grant
- Makeup Artist: Basil Newall
- Production Manager: Donald Toms
- Assistant Director: Ken Baker
- Second Unit Director (Uncredited): David Lane
- Assistant Art Director: Michael Ford
- Sound Recordist: Claude Hitchcock
- Sound Editors: Jack T. Knight (Credited as Jack Knight) and Peter Pennell
- Re-Recording Mixer: Otto Snel
- Lighting Cameraman: Nick Allder
- Electronics: Michael S.E. Downing
- Special Effect Designer / Director: Brian Johnson
- Camera Operator: David Litchfield
- Model Makers (Uncredited): Andrew Kelly and Martin Bower
- Camera Operator: Neil Binney
- Wardrobe: Masada Wilmot
- Continuity: Gladys Goldsmith
- Drivers (Uncredited): Ray Atkins, Steve Smith and Doug Wetherley
- Cutting Room: Frederick Buckman
- Financial Director: Terence Connors
- Production Executive: Reg Hill
- Technical Director: David Lane