| Episode | Credits | Transcript |
Cast[]
- Martin Landau as Commander John Koenig
- Barbara Bain as Dr. Helena Russell
- Barry Morse as Prof. Victor Bergman
- Shane Rimmer as James Kelly
- Carla Romanelli as Melita Kelly
- Prentis Hancock as Paul Morrow
- Clifton Jones as David Kano
- Zienia Merton as Sandra Benes
- Anton Phillips as Dr. Bob Mathias
- Nick Tate as Alan Carter
- Derek Anders as Wayland
===Uncredited===[]
- Tony Allyn and Joe Dunne as Security Guards
- Robert Atiko and Mike Sirett as Technicians
- Sarah Bullen as KateBullen
- Loftus Burton, Laurie Davis, Jacqueline Delhaye, Andy Dempsey, Ann Maj-Brit and Michael Stevens as Main Mission Operatives
- Carol Dee as Patient
- Alan Harris as Alphan
- Judith Hepburn, Diana Reeves and Erica Svenson as Nurses
- Quentin Pierre as Pierce Quinton
- Suzanne Roquette as Tanya Aleksandr
- James Snell as Cousteau
Crew[]
- Directed by Charles Crichton
- Written by Christopher Penfold
- Produced by Gerry Anderson (Executive Producer), Sylvia Anderson (Producer)
- Music by Barry Gray
- Cinematography by Frank Watts
- Editing by Derek Chambers (Credited as Derek Hyde Chambers)
- Supervising Editor: David Lane (Credited as Dave Lane)
- Casting by Michael Barnes
- Production Design by Keith Wilson
- Hair Designer: Helene Bevan
- Makeup Artist: Ann Cotton
- Production Manager: Ron Fry
- Assistant Director: Ken Baker
- Scenic Artist (Uncredited): Bill Beavis
- Props (Uncredited): John Chisholm
- Sound Recordist: David Bowen
- Sound EditorRoy Lafbery
- Re-Recording MixerOtto Snel
- Special Effects Director: Nick Allder
- Electronics: Michael S.E. Downing
- Camera Operator: Frank Drake
- Special Effects: Brian Johnson
- Lighting Cameraman: Harry Oakes
- Model Maker (Uncredited): Andrew Kelly
- Stunts (Uncredited): Marc Boyle, Joe Dunne, Dorothy Ford and Eddie Stacey
- Camera Operator: Neil Binney
- Costumes: Moon City: Rudi Gernreich
- Wardrobe: Eileen Sullivan
- Music Associate: Vic Elms
- Music Editor: Alan Willis
- Composer: Stock Music (Uncredited): Gustav Holst
- Script Editor: Johnny Byrne
- Continuity: Gladys Goldsmith
- Drivers: Ray Atkins, Steve Smith and Doug Wetherley
- Runner (Uncredited): Jeremy Coote
- Stand-In for Barbara Bain: Suzanne Heimer
- Stand-In for Martin Landau: Alan Meacham
- Stand-In for Barry Morse: Ron Watkins