Development This was the last story to be produced under the aegis of
Doctor Who creator
Sydney Newman, who left his position as
Head of Drama at the BBC upon the expiration of his contract at the end of 1967. The four key production roles for this story were all taken by men heavily involved in the development of Doctor Who. Author
David Whitaker had been the show's first script editor;
Barry Letts, directing the show for the first time, later became the show's producer (for the majority of the
Jon Pertwee era), executive producer, and occasional script writer; script editor
Peter Bryant became the show's producer from the next story;
Innes Lloyd was the show's current producer, but left after this story. Much like the
First Doctor serial ''
The Massacre of St Bartholomew's Eve'' (1966), this serial was influenced by the lead actor's desire to play roles other than the Doctor. Initially, it was planned that Troughton's two characters would meet more than once, but due to the technical complexity, there was eventually only the one confrontation scene, at the story's climax (utilising editing and a split-screen technique).
The Enemy of the World is the only serial in
season 5 which lacks a "monster" (e.g. the
Yeti or
Cybermen) as the villain and does not follow the "base under siege" structure.
Filming and editing stood in for the Australian coast. Much of the location filming took place at
Climping Beach by
Littlehampton,
West Sussex from 5 to 8 November 1967. It was Troughton's idea that the Doctor should strip to his long johns when exploring the beach. The helicopter was hired from
Bristow Helicopters; this was the first time a helicopter was used in
Doctor Who. The BBC-owned Villiers House in
Ealing stood in for Kent's office and was filmed on 9 and 10 November. Interior TARDIS scenes, including the meeting of the Doctor and Salamander in Episode 6, Salamander's speech that the characters view in Episode 1, and model filming took place 10-13 November. The rest of the taping took place weekly on Saturdays from 2 December 1967 to 6 January 1968. Barry Letts planned six
split-screen shots showcasing Salamander and the Doctor. He called for a
matte box to mask half of the camera lens, having read about the technique used for old
Hollywood films. The film was rewound after the first take and Troughton was then filmed in his other costume. However, after the first such shot, the camera jammed, and no more split-screen takes were filmed. Later, Letts mentioned this to
Derek Martinus, director of the
preceding story, who brought Letts up to date with the contemporary technology of filming normally then using an
optical printer to combine the material. The now-disproved notion of the switch-over occurring at Episode 3 was most likely due to an error in documentation. The editing of the serial was plagued by several issues. 45 minutes of footage from Episode 1 were lost because the tape had been reversed, causing a backlog that led to an eleven-hour editing session to finish Episodes 4 and 5 on 1 January 1968.
Cast notes Frazer Hines and Deborah Watling did not appear in episode 4, as they were on holiday. Many of
The Enemy of the World's cast reappeared in later
Doctor Who stories.
Milton Johns appeared in
The Android Invasion (1975) as Guy Crayford and
The Invasion of Time (1978) as Castellan Kelner.
Colin Douglas played Reuben the lightkeeper (as well as voicing the
Rutan scout) in the 1977 serial
Horror of Fang Rock.
George Pravda later appeared in
The Mutants (1972) as Jaeger and
The Deadly Assassin (1976) as Castellan Spandrell. ==Broadcast and reception==