Serial: CCC  Episode Nos. 265, 266, 267, 268, 269, 270, and 271.  Title: The Ambassadors of Death

A British space capsule has run into trouble on a mission to Mars. The astronauts have not responded once during their trip back to Earth, and upon arrival, refuse to come out of the capsule! What’s more, it seems that people within the British government itself are conspiring against UNIT to kidnap the astronauts! And then there’s the matter of the mysterious radio signals the capsule’s emitted, and how when the astronauts finally do come out... they are lethal to the touch and highly radioactive. Fortunately for UNIT, the Doctor is on their side... but whose side is everyone else on?

starring Jon Pertwee as Doctor Who, Caroline John as Liz Shaw, Nicholas Courtney as Brigadier Lethbridge-Stewart, and John Levene as Sergeant Benton. Written by David Whitaker, Produced by Barry Letts, Directed by Michael Ferguson.

Originally transmitted from 21 March 1970 to 2 May 1970 on BBC1.

55% of the color originally on this story has been restored. Episode 1 is completely color from the surviving original archive videotape.

Episode 2 is 10 minutes of color, 15 minutes of black and white. Episode 3 is 4 minutes color/21 b&w. Episode 4 is all b&w.

Episode 5 is all color, and VidFIRE was also used to improve the video look. Episode 6 is 16 minutes color/8 b&w. Episode 7 is

16 minutes color/9 b&w. The color and partly-color episodes have not been broadcast in North America in color since the 1970s.

This is a 2-tape set.