Serial 4F:
Terror Of The Zygons


Working Titles: Loch Ness, T
he Secret Of The Loch, The Secret Of Loch Ness, The Loch Ness Monster, The Zygons.
Starring: Tom Baker (The Fourth Doctor)
, Nicholas Courtney (Brigadier Lethbridge Stewart), John Levene (RSM Benton), Elisabeth Sladen (Sarah Jane Smith), Ian Marter (Surgeon-Lieutenant Harry Sullivan).

Plot
The Brigadie
r summons the Doctor back to Earth to investigate mysterious goings-on around Loch Ness in Scotland. The Doctor, Sarah Jane and Harry discover that the Loch Ness Monster is no myth -- in fact, it is really the Skarasen, a cybernetic reptile used as a servant by shape-shifting aliens known as the Zygons. The Zygons are paving the way for an invasion of Earth, and have already used their powers to infiltrate the local authorities.

Production
In casting about for new writers for Docto
r Who script editor Robert Holmes invited an acquaintance named Robert Banks Stewart to discuss ideas for the programme. After their meeting in early 1974, Stewart devised a storyline for a six-part adventure called The Secret Of Loch Ness. Stewart felt that the Scotland's legendary Loch Ness Monster would make an ideal basis for a story because there were so few details about the mythical creature. Stewart's serial was commissioned by May. Although at first focussing on the Loch Ness Monster itself, Holmes encouraged Stewart to concentrate more on the Zygons, the shape-shifting aliens of the story. As the story evolved, it was known variously as The Loch, The Secret Of The Lock, The Loch Ness Monster, The Zygons and finally Terror Of The Zygons.

Throughout 1974, buzz was building
about Gerry and Sylvia Anderson's new science-fiction series Space: 1999, set for a September 1975 debut on ITV, the commercial channel which was the BBC's principal rival. Since 1970, Doctor Who had lead off the BBC's winter season in late December or early January, and BBC was afraid that if Season Thirteen started three months after Space: 1999 debuted, viewing figures might be compromised. Consequently, it was decided that Doctor Who thirteenth season would be brought forward to an August 1975 debut. This meant that the thirteenth recording block, which normally wouldn't begin until September, would also have to start earlier. In the end, it was decided to trim Season Twelve from twenty-six episodes to twenty, to air the last story of the twelfth production block as part of Season Thirteen, and to basically have the twelfth and thirteen blocks run into one another with no appreciable break in between.

What all this meant was that Terror Of The Zygons, origi
nally intended to be the last story of Season Twelve, would now be the first story of Season Thirteen. This also necessitated a reduction in length from six episodes to four. Holmes helped Stewart make the necessary cuts, with much of the material lost involving location material in the Scottish Highlands, it having been decided at this point that taking a film crew to Scotland was prohibitively expensive. Terror Of The Zygons would still be made at the end of the twelfth production block, but because the thirteenth block now began immediately thereafter, the difference was essentially meaningless.

One
extra requirement for Serial 4F was that it had to remove Harry Sullivan from the TARDIS crew. The character had been devised because plans had originally called for the Fourth Doctor to be elderly, and the casting of Tom Baker had made Harry all but redundant. It was decided that Harry would follow in the footsteps of the rest of the UNIT crew and become a semi-regular character.

It was with this story that Douglas Camfi
eld made his return to Doctor Who. Once a prolific Who helmer, Camfield had not worked on the program since 1970, when he experienced heart trouble while making Inferno. Despite his love of Doctor Who, the stress associated with the programme forced him to stop working on it, until Stewart's script finally drew him back.

The first material recorded for Terror Of
The Zygons involved the "Loch Ness Monster" itself, the Skarasen. One version of the creature was designed for stop-motion animation while another was a puppet-type design for real-time filming. Unfortunately, both Camfield and producer Philip Hinchcliffe were very disappointed by the resulting footage. As a result, only a bare minimum was included in the final edit, and some scenes were rewritten to avoid having to show the Skarasen on-screen.

Location filming occurred in late Marc
h 1975, with Charlton in West Sussex doubling for the Scottish village of Tullock. Studio recording then began on April 7th. Unusually for the twelfth production block (which had consisted of fortnightly Monday/Tuesday studio tapings), the second block of recording took place on Tuesday the 22nd and Wednesday the 23rd. The latter also marked the final work by Nicholas Courtney as a semi-regular on Doctor Who. Courtney was well aware that Hinchcliffe wanted to move away from the UNIT format of the early Seventies, and indeed the two had discussed possible ways of writing out the Brigadier, with Courtney suggesting he be killed in a final blaze of glory (an idea Hinchcliffe felt would be inappropriate for such a popular character). Indeed, Terror Of The Zygons was not intended to be the Brigadier's last appearance, but a planned return later in Season Thirteen did not pan out because of scheduling conflicts. Courtney would return to Doctor Who several times, however, including Mawdryn Undead and The Five Doctors in 1983, Battlefield in 1989, and the radio plays The Paradise Of Death and The Ghosts Of N-Space in the Nineties. In the meantime, Courtney continued to work prolifically on television, stage and film.

Terror Of The Zygons got Doctor Who's thirteenth se
ason started on August 30th. It was the first time since The Dominators in 1969 that a Doctor Who season had started in August.