is the third serial of the seventh season of Doctor Who , originally broadcast in seven weekly parts from March 21 to May 2, 1970 . It features Jon Pertwee as the Third Doctor in his first major venture into space during his Earth-bound era. Plot Summary
: Features the first instance of the TARDIS console being used while removed from the TARDIS. It is also known for its gritty "Quatermass-style" thriller vibe and extensive location filming. Episode List & Original Air Dates Original Air Date Episode 1 March 21, 1970 Episode 2 March 28, 1970 Episode 3 April 4, 1970 Episode 4 April 11, 1970 Episode 5 April 18, 1970 Episode 6 April 25, 1970 Episode 7 May 2, 1970 Critical Reception
: The kidnapping is orchestrated by General Carrington , a xenophobic ex-astronaut who intends to use the ambassadors to incite a war against their kind. "Doctor Who" The Ambassadors of Death: Episode ...
: Primarily credited to David Whitaker , though the final script was heavily rewritten by Malcolm Hulke , Trevor Ray , and Terrance Dicks .
: The Doctor and UNIT eventually thwart Carrington's broadcast plans and arrange a peaceful exchange: the ambassadors return home, and the human astronauts are released safely to Earth. Production & Cast is the third serial of the seventh season
: A recovery mission, Recovery 7 , returns to Earth, but the occupants are kidnapped by criminals led by Reegan . It is discovered that the "astronauts" are actually radiation-dependent alien ambassadors who swapped places with the humans.
: Includes Jon Pertwee (The Doctor), Nicholas Courtney (Brigadier Lethbridge-Stewart), and Caroline John (Liz Shaw). It is also known for its gritty "Quatermass-style"
: The Doctor takes a solo flight into space—without the TARDIS—to find the real astronauts aboard an alien mother ship.