The Doctor, Sarah and Harry return to the Nerva Beacon, but inadvertently appear thousands of years before they left. Whilst awaiting the arrival of the TARDIS, they discover the Beacon -- at this point in time used to direct interstellar traffic -- is overrun by a plague which has wiped out most of the crew. The culprits are the Cybermen, on a vendetta to destroy the deciding factor in humanity's war against them: Voga, the Planet of Gold.

In 1972, Doctor Who producer Barry Letts had enjoyed ratings success when he resurrected the Daleks for Day Of The Daleks, following half a decade's absence from the programme. When it came to planning the first season for the Fourth Doctor, Letts hoped that lightning might strike twice and decided to bring back the series' other prominent monster race, the Cybermen. The Cybermen had not been featured in a Doctor Who serial since The Invasion in 1968.

To write the Cyberman adventure, Letts turned to former Doctor Who story editor Gerry Davis, who had cocreated the villains with Kit Pedler. Davis' last scripting contribution to the programme had been 1967's The Tomb Of The Cybermen. Concerned about the Doctor Who budget, Letts asked Davis to make use of the same setting (albeit in a different time period) as another planned Season Twelve serial, Christopher Langley's “Space Station”, permitting the two adventures to share sets. The storyline for Revenge Of The Cybermen (at this point designated Serial 4C) was commissioned on May 9th, 1974.

Davis' original notion was that, in his story, Langley's space station would be operating as a casino. The Cybermen would be using their small, robotic Cybermats to spread a plague (intended to be the same virus introduced in 1967's The Moonbase), only to have the Doctor use the casino's gold reserves to eradicate them. Script editor Robert Holmes contracted Davis to turn his storyline into full scripts (under the slightly amended title of “The Revenge Of The Cybermen”) on June 6th, although it was agreed that the idea of portraying the space station as a casino would be dropped. Around the same time, Langley's scripts were discarded; the Cyberman serial would now be acting as a sequel to The Ark In Space by John Lucarotti.

As Davis set to work, the production office secured Kit Pedler's permission to make use of the Cybermen; the deal was officially reached on July 8th. Davis' scripts had now become “Return Of The Cybermen”, with the space station serving as a relay beacon. The writer gave each episode its own title, even though this practise had been abandoned while Davis was a member of the production team. In the absence of a concrete idea of how Tom Baker would be portraying the new Doctor, Davis also elected to essentially write the character in the vein of Patrick Troughton's Second Doctor, including the use of such signature elements as his 500-year diary.

Hewing to Letts' original request for a fairly inexpensive serial, most of Davis' action took place on board the Nerva beacon. The Nerva crew at this stage include a scientist named Anitra Berglund, and Warner was female. The Cybermen have been smuggled onto Nerva by Kellman before the story begins, with the aim of destroying a gold-rich asteroid in the station's vicinity. Kellman has betrayed a group of miners (led by a man named Evans, and also including Jones and Williams) who have been marooned on the asteroid for a quarter of a century; they eventually kill him by dynamiting a tunnel. The Doctor manages to reprogram the Cybermats to destroy the Cybermen using gold dust he has retrieved from the asteroid.

Both Holmes and new producer Philip Hinchcliffe were concerned throughout the writing process that Davis was pitching his scripts at an audience younger than Doctor Who was now targetting. Hinchcliffe was also concerned that Sarah was largely extraneous to the action, and that Harry dominated episode four at the expense of the Doctor. Davis agreed to a number of rewrites (which included eliminating Berglund and switching Warner's gender). Around the middle of September, the title was changed back to “The Revenge Of The Cybermen”, while the production code was amended to Serial 4D.

At the end of the month, however, it became clear that more money was available for “The Revenge Of The Cybermen” than had previously been anticipated. Hinchcliffe and Holmes decided that more material should therefore take place on the asteroid, which could now been filmed on location. Deciding to tackle this overhaul of Davis' scripts himself, Holmes replaced the miners with an alien race. The asteroid itself increased in stature to that of a moon or planet, and Holmes considered several names -- including Alanthea and Vega -- before finally christening it Voga, after a mythical Atlantic island sought by Christopher Columbus. Originally, Holmes had Kellman perish during Lester's self-sacrifice, before eventually killing him off in the rockfall. Around this point, the serial's title reverted to its original designation, Revenge Of The Cybermen.

Work on the story began with a day at the BBC Television Centre Puppet Theatre on November 12th, where all the model shots were completed. The director was Michael E Briant, who had last worked on Death To The Daleks the year before. After deciding against reusing the remaining Cyberman costumes left over from The Invasion due to their antiquated appearance, Briant had four new suits made for Revenge Of The Cybermen. For the first time, the rank of Cyberleader was visibly denoted by painting the “handlebar” section of his helmet black rather than silver.

For the scenes set on Voga, Briant decided to make use of the network of natural caverns known as Wookey Hole, near Wells in Somerset. Inhabited by primitive man since around 50,000 BC, Wookey Hole in modern times had gained a reputation for being haunted by a Dark Ages witch, now petrified as one of the cave's rock formations. While scouting the complex, Briant's wife Monique discovered several Iron Age arrowheads in the sand, which she kept as a memento. Some crewmembers would come to believe that this precipitated a chain of strange occurrences and bad luck which thereafter beset the production.

The first event attributed to this “curse” occurred later in the reconnaissance trip, when Briant encountered an individual dressed in spelunking gear, of whom the Wookey Hole staff had no knowledge. The director came to believe that this was actually the ghost of an Irish potholer who had perished in the caves three years earlier. The four-day location shoot then began on November 18th. On the first day, the boats hired for use as the Vogan skimmers repeatedly broke down. Assistant floor manager Rosemary Hester suffered an attack of claustrophobia and had to be replaced by Russ Karel, while unit armourer Jack Wells was also very unwell.

Matters worsened on the 20th, the same day that some of the crew disobeyed their instructions and interfered with the “Witch” formation. That afternoon, the boat being driven by Elisabeth Sladen on the pond in the “Witch's Parlour” cave went haywire, forcing the actress to jump overboard to avoid smashing into a cavern wall. Sladen nearly drowned before being pulled from the water by stuntman Terry Walsh, who fell ill afterward. Later, a ladder collapsed under an electrician, who suffered a broken leg. The final day saw visual effects assistant Tony Harding experience unusual difficulty in setting up basic pyrotechnics. Briant subsequently blamed all of these occurrences on the arrowheads taken by his wife, and had them disposed of.

Fortunately, the remainder of the schedule proceeded under less supernatural conditions. As usual for four-part Doctor Who stories, Revenge Of The Cybermen was allocated a pair of two-day studio sessions. As he had done on Death To The Daleks, however, Briant elected to use the first day for rehearsals and the second day for recording, rather than rehearsing then recording each scene as usual. Briant also favoured recording on a set-by-set basis rather than episode-by-episode.

The first session took place in TC1 on Monday, December 2nd and Tuesday the 3rd. All the material set on the crew deck and the transom was completed, along with scenes in the control rooms from the first three installments. The second session occurred exactly a fortnight later, on the 16th and 17th -- this time in TC3. The remainder of the outstanding material was taped, with the exception of the serial's opening effects shot, which was recorded during the making of Genesis Of The Daleks in TC8 on February 10th, 1975.

It had long been planned that, despite the order in which they were being made, Revenge Of The Cybermen would succeed Genesis Of The Daleks in the broadcast schedule, making it the fifth adventure of Season Twelve. The original intention, however, had been to follow the Cyberman tale with Terror Of The Zygons, the final serial to be made as part of the twelfth recording block and the conclusion of the story sequence begun in Robot, the season premiere.

In January, however, the BBC decided that Doctor Who's thirteenth season should begin in the autumn -- the first time this had transpired since 1968 -- in order to get a jump on rival ITV's lavish new science-fiction drama, Space: 1999. Consequently, Terror Of The Zygons was held over to start Season Thirteen. The result of this was that the broadcast of Revenge Of The Cybermen part four on May 10th brought an end to Doctor Who's truncated twelfth season.

Gerry Davis was unhappy with what would turn out to be his final writing contribution to Doctor Who. Nonetheless, Revenge Of The Cybermen earned a peculiar distinction in the programme's history when it was chosen in 1983 to be the first Doctor Who story released for public consumption on videocassette. The honour was more than a little dubious, however: although touted as the choice of attendees at the Twenty Years Of A Time Lord event at Longleat House that April, Revenge Of The Cybermen was actually selected by BBC Video to replace the fans' true choice: Tomb Of The Cybermen, which at the time was missing from the BBC Archives. Nonetheless, Revenge Of The Cybermen spearheaded a range which would grow to encompass more than 130 titles before coming to an end -- having essentially exhausted its supply of material and on the verge of being superceded by the DVD format -- twenty years later.

• Doctor Who: The Handbook: The Fourth Doctor by David J Howe, Mark Stammers and Stephen James Walker (1992), Virgin Publishing, ISBN 0 426 20369 8.
• Doctor Who: The Seventies by David J Howe, Mark Stammers and Stephen James Walker (1994), Virgin Publishing, ISBN 1 85227 444 1.
• Doctor Who Magazine #297, 15th November 2000, “Archive: Revenge Of The Cybermen” by Andrew Pixley, Panini Publishing Ltd.
• Doctor Who Magazine Special Edition #8, 1st September 2004, “You Ain't Seen Nothing Yet” by Andrew Pixley, Panini Publishing Ltd.
• In-Vision #5, June 1988, “Production” edited by Justin Richards and Peter Anghelides, Cybermark Services.