The Deadly Assassin is the third serial of the 14th season of the British science fiction television programme Doctor Who, which was first broadcast in four weekly parts on BBC1 from 30 October to 20 November 1976.
In the serial, the renegade alien Time Lord the Master (Peter Pratt) seeks to restore his life force by disrupting a power source that would destroy the planet Gallifrey along with his archenemy the Fourth Doctor (Tom Baker).
Following Elisabeth Sladen's departure, Tom Baker told producer Philip Hinchcliffe that he wanted to do a story without a companion.
[1] Robert Holmes said that it was difficult to write the script for The Deadly Assassin without anyone for the Doctor to share his thoughts and plans with, which was the usual role of the companion.
[citation needed] Working titles for this story included The Dangerous Assassin (which Holmes changed to "deadly" because he thought it "didn't sound right").
Other parts played by Horsfall in Doctor Who were Gulliver in The Mind Robber (1968) and Taron in Planet of the Daleks (1973), all of which were directed by David Maloney.
Peter Pratt, who plays the Master, was previously a leading man with the D'Oyly Carte Opera Company and a radio actor.
[4] The cliffhanger to Part Three—where Goth holds the Doctor's head underwater in an attempt to drown him—came in for heavy criticism, particularly from the 'clean-up TV' campaigner Mary Whitehouse.
[9] Paul Cornell, Martin Day and Keith Topping wrote of the serial in The Discontinuity Guide (1995), "The reputation of The Deadly Assassin rests with its violence and its revelations about the Doctor's people and their culture.
He described "the Master's putrid skull and split bangers for fingers" as "the most revolting images presented on teatime TV" but was positive towards its supporting characters, though he did criticise the Matrix sequences for being more earthly rather than alien, despite them being constructed from deceased Time Lords.
[17] Tat Wood suggests it is "blindingly obvious" that the story was largely inspired by the film and book The Manchurian Candidate.
[11] A novelisation of this serial, written by Terrance Dicks, was published by Target Books in October 1977, entitled Doctor Who and The Deadly Assassin.