Planet of Evil

Planet of Evil is the second serial of the 13th season of the British science fiction television series Doctor Who. It was first broadcast in four weekly parts on BBC1 from 27 September to 18 October 1975.

The serial is set on and above the planet Zeta Minor, the last undiscovered planet in the known universe, more than 30,000 years in the future. In the serial, the Morestran geologist Sorenson (Frederick Jaeger) seeks to exploit the antimatter minerals on the planet to use as a power source for his own planet when he and the military mission looking for him are attacked by a creature from a universe of anti-matter.

In the story, the Fourth Doctor and Sarah Jane Smith arrive on planet Zeta Minor in response to a distress call. They find a Morestran geological expedition attacked by an unseen killer, leaving only Professor Sorenson alive. A military mission arrives to investigate, initially suspecting the Doctor and Sarah Jane. The true culprit is revealed to be an antimatter creature, provoked by Sorenson's removal of antimatter samples from a pit connecting two universes. The Morestran ship is dragged back to the planet due to the antimatter on board, and Sorenson transforms into a life-draining monster. The Doctor ultimately returns Sorenson and his samples to the pit, fulfilling a bargain with the antimatter creature. Sorenson is restored, and the Morestran ship is freed from the planet's influence.

The plot was inspired by the film Forbidden Planet and the novella Strange Case of Dr Jekyll and Mr Hyde, with a focus on antimatter. The jungle setting was entirely studio-bound, with an impressive set design that earned accolades.