4H. Planet Of Evil

Season Thirteen - 1975/1976

Script Editor: Robert Holmes
Writer: Louis Marks
Produced by: Philip Hinchcliffe
Director: David Maloney
Designer: Roger Murray-Leach
Incidental Music: Dudley Simpson


The Doctor and Sarah respond to a distress call and the TARDIS materialises on Zeta Minor at the edge of the known Universe. A geological party from the planet Morestra has run into trouble, and only Professor Sorenson has survived.

A military party from Morestra has been sent to investigate the mysterious disappearances. The Doctor discovers that Sorenson has been attempting to take anti-matter from the planet, and an entity from the anti-matter universe has been retaliating.

The Doctor communicates with the entity and secures freedom for all on the condition that no anti-matter is taken from the planet. The Doctor convinces the military party to leave the anti-matter behind, and the ship manages to take off. Sorenson, however, has smuggled on board a consignment, and the ship is gradually dragged back to the planet..

Sorenson becomes infected by the anti-matter, and transforms into anti-man. The Doctor manages to get himself, Sorenson and the anti-matter back onto the planet. He throws Sorenson and the anti-matter into the entity's pit, fulfilling his part of the bargain.

Sorenson is returned, and the ship is allowed to leave. Sorenson has amnesia, and the Doctor suggests that he derives power from planetary motion.

Regular Cast

  • Sarah Jane Smith: Elisabeth Sladen

Guest Cast

  • Professor Sorenson: Frederick Jaeger
  • Vishinsky: Ewen Solon
  • Salamar: Prentis Hancock
  • De Haan: Graham Weston (1-3)
  • Morelli: Michael Wisher (1-3)
  • Ponti: Louis Mahoney (1-2)
  • O'Hara: Hayden Wood (1-2)
  • Reig: Melvyn Bedford (3-4)
  • Monster: Mike Lee Lane
  • Baldwin: Tony McEwan (1)
  • Cewleader Ranjit: Michael Wisher (4)
  • Sorenson Monsters: Ray Knight (4), Douglas Stark (4)
  • Morestrans: Alfred Coster (1-2), Richard Eden, Max Faulkner (1-2), Julian Hudson, David Rolfe (1,2,4), Terry Walsh (1,2,4)
  • Double for the Doctor and Sorenson: Terry Walsh (2,4)

Original broadcast on the BBC

Channel Title Date Viewers Rating
BBC 1 406. Part One Saturday, September 27, 1975 5:45 PM - 6:10 PM 10.4M
BBC 1 407. Part Two Saturday, October 4, 1975 5:45 PM - 6:10 PM 9.9M 55%
BBC 1 408. Part Three Saturday, October 11, 1975 6:05 PM - 6:30 PM 9.1M 57%
BBC 1 409. Part Four Saturday, October 18, 1975 5:45 PM - 6:10 PM 10.1M 54%

Click here to show repeat broadcasts on the BBC


  • Ealing Television Film Studios
  • Television Centre Studio 3
  • Television Centre Studio 6


Part 1: When the Doctor and Sarah first leave the TARDIS, the light on top of the police box keeps flashing (this is only supposed to happen in flight). And when Sarah returns later in the episode, the light has stopped flashing.

Part 4: When the Doctor drags the antimatter-infected Sorenson into the TARDIS, he dematerialises without closing the doors.

Part 4: As Tom Baker walks around the anti-matter pool, his foot crashes through the set!