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Each episode is identified with date of transmission, duration, ratings in millions, and (for 1963-1974 only) archive status.
30 August 1975 | 21'41" | 8.4
06 September 1975 | 25'08" | 6.1
13 September 1975 | 24'09" | 8.2
20 September 1975 | 25'22" | 7.2
(Doctor Who), Elisabeth Sladen
(Sarah Jane Smith), Nicholas Courtney
(Brigadier Lethbridge-Stewart), John Woodnutt
(Duke of Forgill / Broton), John Levene
(RSM Benton), Lillias Walker
(Sister Lamont), Robert Russell
(The Caber), Angus Lennie
(Angus), Tony Sibbald
(Huckle), Hugh Martin
(Munro), Bruce Wightman
(Radio Operator), Bernard G. High
(Corporal), Peter Symonds
(Soldier), Keith Ashley
(Zygon), Ronald Gough
The Brigadier has summoned the Doctor as there have been several mysterious attacks on oil rigs in the North Sea off the Scottish coast. The Doctor, somewhat dismissive of the urgency, reluctantly agrees to help. In the meantime, Harry finds a body washed up on the beach, but when he tries to help he is shot by the Caber, a highland gamekeeper employed by the Duke of Forgill.
Harry is taken to the sick bay of the Hibernian Oil Company where Sarah is attacked by a hideous orange humanoid monster and knocked unconscious. When she comes to she finds herself locked in a pressure chamber.
Investigating all these happenings, the Doctor realises that the oil rigs have been attacked by something huge and monstrous - it later turns out to have been a cyborg called the Skarasen - and that the attacks are being controlled from Loch Ness. He rescues Sarah but Harry has been abducted and duplicated by the humanoid creatures. The Doctor realises that the Duke of Forgill himself is involved, and in Forgill Castle Sarah discovers an entrance to an underwater spacecraft.
The craft belongs to the Zygons, who centuries ago arrived on Earth, and with their ship crippled, awaited rescue. Their home planet has since been destroyed in a stellar explosion and now they want to take control of the Earth. To this end the Zygon leader Broton has taken on the form of the Duke to infiltrate a World Energy Conference in London which they plan to destroy with the Skarasen.
The Zygons on Earth are destroyed when the Doctor engineers an explosion in their space craft, and Broton is shot by UNIT troops at the Conference. The Skarasen, now without the controlling influence of the target reciprocator, makes its way back to the only home it knows, Loch Ness, there to be occasionally mistaken for the fabled Loch Ness Monster.
The Doctor and Sarah decide to travel back to London by TARDIS, but Harry, feeling that his time with the Doctor has all got a little too much for him, elects for the safer and more reliable method of British Rail.
Synopsis from Doctor Who: The Fourth Doctor Handbook by David J. Howe, Mark Stammers and Stephen James Walker, reprinted with permission; further reproduction is not permitted.
(Assistant Floor Manager), James Acheson
(Costumes), Nigel Curzon
(Designer), Peter Hall
(Film Cameraman), Ian McKendrick
(Film Editor), Geoffrey Burgon
(Incidental Music), Sylvia James
(Make-Up), Philip Hinchcliffe
(Producer), Edwina Craze
(Production Assistant), George Gallacio
(Production Unit Manager), Robert Holmes
(Script Editor), Dick Mills
(Special Sounds), John Dixon
(Studio Lighting), Michael McCarthy
(Studio Sound), Delia Derbyshire
(Theme Arrangement), Ron Grainer
(Title Music), John Horton
(Visual Effects), John Friedlander
Originally planned as the closing segment of season 12, "Terror of the Zygons" was postponed to start season 13 in early August to offset the challenge of ITV's new show "Space: 1999"; it was originally to be a six-part story but was pared down to four for this reason. The original working title was "The Secret of Loch Ness" and also bore the titles "The Loch," "The Secret of the Loch," "The Loch Ness Monster" and "The Zygons". This was the final story to feature Harry Sullivan as a regular cast member, although Sullivan would later return briefly in "The Android Invasion"; it was also the final story in which the Brigadier and Benton would appear as regulars (the Brigadier would later return for guest appearances during the 1980's). Douglas Camfield returned to the program for the first time since 1970. The design of the Zygons was based partly on a human embryo, while the Skarasen was achieved by using two puppets, a small stop-motion one and a larger one for the Thames emergence sequence; both were realized poorly. The Zygons were designed to glow internally by the provision of a series of lights inside the rib cage and the head, all powered from a concealed battery pack; the idea was not used much during recording. A scene of the TARDIS arriving invisibly at the start of part one was dropped after filming because of technical difficulties discovered during editing. John Woodnutt also played Broton in all four episodes, but was uncredited for this on screen.
For more in-depth information about the contents of this story, a complete episode-by-episode detailed breakdown can be found at the Doctor Who Reference Guide
Released as "Terror of the Zygons" in the UK [November 1988] and Australia/New Zealand [April 1987] (BBC catalog #4186), US/Canada [April 1991] (CBS/FOX catalog #5422; never reclassified with WHV catalog #); omnibus (movie) format, photomontage cover. Rereleased in unedited format in the UK [August 1999] and Australia/New Zealand [January 2000] (BBC catalog #6773), US/Canada [May 2000] (WHV catalog #E1410); episodic format, with new photomontage cover. Also released on Laserdisc in the UK in 1997, details unknown.
Released on audio by the RNIB, narrated by Gabriel Woolf. A music suite from the story was released on "Doctor Who: Terror of the Zygons" arranged by Geoffrey Burgon, released by BBC Music (2000).
Novelised as “Doctor Who and the Loch Ness Monster” by Terrance Dicks (Target #40), first released in 1976 with cover art by Chris Achilleos. Re-released as “Doctor Who – Terror of the Zygons” in 1993 with cover illustration by Alister Pearson. Released via Pinnacle Books in 1979 in US (#6); this version was also used in “The Adventures of Doctor Who” hardcover published in US by Nelson Doubleday.
For more details on the various novelizations of this story, with additional background material, artwork and details of both UK and foreign releases, visit On Target