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 castSarah Jane Smith: Elisabeth Sladen;
Guest castProfessor 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);
Uncredited cast: 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);
|BBC 1||406||Part One||Sat 27 September 1975||5:45 pm - 6:10 pm||10.4M||19th|
|BBC 1||407||Part Two||Sat 4 October 1975||5:45 pm - 6:10 pm||9.9M||24th|
|BBC 1||408||Part Three||Sat 11 October 1975||6:05 pm - 6:30 pm||9.1M||29th|
|BBC 1||409||Part Four||Sat 18 October 1975||5:45 pm - 6:10 pm||10.1M||26th|
Repeats (on the BBC)
This programme does not have any outside filming
Ealing Television Film Studios; Television Centre Studio 3; Television Centre Studio 6;
Bloopers and mistakes
Episode 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.
Episode 4: When the Doctor drags the antimatter-infected Sorenson into the TARDIS, he dematerialises without closing the doors.
Episode 4: As Tom Baker walks around the anti-matter pool, his foot crashes through the set!
Notes and trivia
This programme has no additional notes.
This programme has no other working titles, or they have not been yet been entered.