'The Ambassadors of Death' (7 Parts) Story Code 'CCC' by David Whitaker (and Malcolm Hulk)**

The Doctor, Liz and UNIT are at Space Control, investigating the mystery surrounding Mars Probe 7, which began its return journey from Mars seven months ago, but has made no contact with Earth in that time. The centre is headed by Professor Ralph Cornish, who is overseeing the Recovery 7 rescue mission, which has now also run into difficulties. Recovery 7 returns to Earth, but after landing, the astronauts are kidnapped. Liz notices that the Geiger counter is at a maximum, which indicated radiation levels that would have killed any humans aboard. It transpires that the ship's occupants were not the human crew after all, but instead are a trio of radiation dependant alien ambassadors, who have swapped places with them. The Doctor makes a solo flight in Recovery 7, and docks with Mars Probe 7, which is still orbiting in space. A huge alien spaceship intercepts the Probe, and the Doctor is taken on board, where he finds the real astronauts unharmed. The alien captain threatens to destroy the Earth unless the three ambassadors are released. The Doctor is allowed to return to Earth, and discovers that the kidnapping of the ambassadors is part of a scheme devised by General Carrington, a xenophobic ex-astronaut. The General plans to discredit the aliens, and to convince the world's authorities to wage war against them. The Doctor and UNIT stop his plans, and arrange for the safe exchange of the astronauts.

Jon Pertwee (Doctor Who), Caroline John (Liz Shaw), Nicholas Courtney (Brigadier Lethbridge-Stewart), Ronald Allen (Ralph Cornish), Robert Cawdron (Taltalian), John Abineri (Carrington / General Carrington), Ric Felgate (Van Lyden), Michael Wisher (John Wakefield), Cheryl Molineaux (Miss Rutherford), Ray Armstrong (Grey), Robert Robertson (Collinson), Dallas Cavell (Quinlan); Bernard Martin, Joanna Ross, Carl Conway (Control Room Assistant); Juan Moreno (Dobson), James Haswell (Corporal Champion), Derek Ware (Unit Sergeant), William Dysart (Reegan), Cyril Shaps (Lennox), Gordon Sterne (Heldorf); Steve Peters, Neville Simons, Ric Felgate (Astronauts); Max Faulkner (Unit Soldier), John Lord (Masters), Tony Harwood (Flynn); John Levene (Sergeant Benton), James Clayton (Private Parker), Roy Scammell (Technician), Peter Noel Cook (Alien Space Captain), Peter Halliday (Aliens' Voices), Steve Peters (Lefee), Neville Simons (Michaels), Geoffrey Beevers (Private Johnson)

Produced by Barry Letts
Directed by Michael Ferguson

TX:
Part 1 - 21st March, 1970 @ 5.15pm - 5.40pm
Part 2 - 28th March, 1970 @ 5.15pm - 5.40pm
Part 3 - 4th April, 1970 @ 5.20pm - 5.45pm
Part 4 - 11th April, 1970 @ 5.45pm - 6.10pm
Part 5 - 18th April, 1970 @ 5.15pm - 5.40pm
Part 6 - 25th April, 1970 @ 5.25pm - 5.50pm
Part 7 - 2nd May, 1970 @ 5.15pm - 5.40pm

Notes:
*Featuring the Third Doctor, Liz, the Brigadier and UNIT

**David Whitaker wrote Parts 1-3; Malcolm Hulk wrote Parts 4-7

*Part 4 was transmitted 30 minutes late due to 'Grandstand' overrunning

*All episodes were made on colour videotape, but for many years later only part 1 existed in full colour in the BBC archives, while parts 2-7 survived as black and white film recordings and poor-quality domestic colour recordings made from a US transmission in the 1970s. For the story's May-2002 VHS release, the usable colour information from the domestic recordings was combined with the black and white picture from the film prints to create a high-quality colour picture; more than half of the story's running time was presented in colour on this release, including all of episodes 1 and 5; the remaining footage was deemed unsuitable for colour restoration. Happily, further advances in technology enabled a fully-restored colour version of the story to be released on DVD in October 2012.

*Working titles: 'Carriers of Death' and 'Invaders From Mars'