The Doctor and Jamie find themselves on a space wheel in the 21st century. Mysterious things have been happening on board the wheel: equipment has been sabotaged, crewmembers have gone missing, and the director, Bennett, is on the verge of a nervous breakdown. The Doctor discovers that the Cybermen, once again intent on invading the Earth, are about to board the wheel, taking control of the entire crew.

As 1967 drew to a close, interest in the Cybermen continued to ride high amongst Doctor Who's production team. On December 5th, permission was sought from Dalek creator Terry Nation to feature both monster races together in the same story. Nation denied this request but did note that further Dalek serials were not out of the question, as long as he was given the right of first refusal. By this time, Cyberman cocreator Kit Pedler had already been in talks for some months about conceiving a new storyline for Doctor Who. With the Dalek/Cyberman team-up having been vetoed, Pedler instead developed an idea which he apparently called “The Space Wheel”.

As with his earlier contributions to the series -- most recently The Tomb Of The Cybermen at the end of the last recording block -- there was no question of Pedler writing the scripts himself. However, his previous writing partner, Gerry Davis (with whom Pedler had collaborated in inventing the Cybermen), had now left his post as Doctor Who's story editor. In his stead, the programme's original story editor, David Whitaker, was brought in to turn Pedler's ideas into full scripts. Whitaker had recently completed work on The Enemy Of The World. He was commissioned on December 14th for what was now called The Wheel In Space; Pedler himself received a belated commission for his storyline on the 18th.

At around the same time, Deborah Watling informed producer Peter Bryant that she would be leaving Doctor Who with Fury From The Deep, the story which would precede The Wheel In Space into production. Story editor Derrick Sherwin was therefore tasked with devising a new companion; in contrast to Victoria, Sherwin created a character who was a scientific and intellectual prodigy. Peter Ling -- who was writing The Mind Robber, the final serial of the fifth recording block -- had used the name “Zoe” for the female companion in his scripts, and with Ling's permission, Sherwin adopted Zoe Heriot as the new character's name.

A year earlier, the Doctor Who production team had hoped that the character of Samantha Briggs, played by Pauline Collins in The Faceless Ones, would become the Doctor's new companion. However, Collins had been unwilling to commit to an ongoing role, and this eventually lead to Watling joining the series as Victoria. Bryant, however, was still eager to bring Collins onto Doctor Who in a regular capacity, and offered her the role of Zoe. When Collins refused once again, Bryant held auditions for the part in early February 1968. Amongst the applicants was Susan George, who was dating Frazer Hines at the time. However, it was Wendy Padbury who won the role.

Padbury had gotten her start on stage, often in children's roles, and also worked as a swimwear model. More recently, she had earned experience on both television and film, including the soap opera Crossroads. Accepting the job on Doctor Who unfortunately meant turning down a part in the award-winning film The Prime Of Miss Jean Brodie. On February 27th, Padbury was contracted for The Wheel In Space and the subsequent story, The Dominators (at this stage still six parts long), with an option for twelve more episodes; she was unveiled to the press via a photocall in Hammersmith Park on March 14th. The next day, Troughton's services were secured through the first serial of the sixth recording block. Meanwhile, Hines had also been issued a new contract on January 19th which covered the three remaining serials of the current block.

The director assigned to The Wheel In Space -- allocated the production code Serial SS -- was Tristan de Vere Cole, who had previously worked on Doctor Who as a production assistant on The Gunfighters. De Vere Cole had only recently attained the post of director, and had helmed episodes of the football soap United!. As de Vere Cole prepared to head into production, several of the supporting characters in The Wheel In Space were renamed, largely to give the space station a more international feel. Nell Corwyn became Gemma Corwyn; Tanya Lerner's surname was changed to the Russian Lernov; Tom Stone gained a promotion when he was rechristened Captain Leo Ryan; Harry Carby became the Italianate Enrico Casali; and Ken was switched to the Asian Chang. Also notable in the script was Jamie's use of the alias “Doctor John Smith” for the Doctor (inspired by a box bearing the label “John Smith & Associates”); this would become a recurring gag for the series.

De Vere Cole spent five days filming at the Ealing Television Film Studios, from March 18th to 22nd. These sessions concentrated on scenes involving the Servo Robot and the spacewalks, with March 21st devoted exclusively to model sequences. Studio recording for Doctor Who was now taking place on Fridays to enable the programme to be taped at the BBC's Television Centre whenever possible. For the recording of part one on April 5th, however, cast and crew temporarily returned to the show's old home at Lime Grove Studio D. This episode saw the final appearance of Victoria Waterfield, albeit only in material filmed for Fury From The Deep.

Patrick Troughton enjoyed a rare holiday the following week and so was absent from Padbury's in-studio debut, which occurred in Television Centre Studio 3. The scripts for the latter episodes were still being worked on at this stage in an effort to better develop Zoe's character. Troughton returned for part three, which was taped in TC1 on April 19th. On this day, the sound box which created the Cyberman voices broke down. Consequently, the climactic scene was later replaced with the cliffhanger reprise taped the following week (in TC3) while the remaining material was remounted alongside part five on May 3rd. For the two final installments, recording moved to Riverside Studio 1, where Doctor Who's second and third production blocks had been taped. Unusually, both of these episodes were captured on 35mm film rather than the standard 625-line videotape.

The Wheel In Space was completed on May 10th. Uniquely, part six -- which was scheduled to end Doctor Who's fifth season on June 1st -- was structured to dovetail explicitly into a repeat of The Evil Of The Daleks (itself the first-ever complete repeat of a Doctor Who story). Twenty seconds from episode two of that serial were edited into the installment, appearing on the TARDIS scanner during the scene where the Doctor warns Zoe about the dangers that might face her should she choose to travel with him. Although Season Five was now complete, the fifth production block would continue with both The Dominators and The Mind Robber, which would be held over to start Season Six in the autumn.

Unfortunately for de Vere Cole, he would not be given the opportunity to return to Doctor Who. He had not gotten along well with Bryant, who felt that the director was circumventing the chain of command by communicating frequently with Pedler and Sherwin, and was unhappy with some of de Vere Cole's modifications to the script. Bryant further alleged that de Vere Cole had exceeded his allotted budget, meaning that the director would not be invited back to Doctor Who. De Vere Cole went on to work on a variety of programmes, including Z Cars, Emmerdale Farm and Survivors.

• Doctor Who: The Handbook: The Second Doctor by David J Howe, Mark Stammers and Stephen James Walker (1997), Virgin Publishing, ISBN 0 426 20516 2.
• Doctor Who: The Sixties by David J Howe, Mark Stammers and Stephen James Walker (1992), Virgin Publishing, ISBN 1 85227 420 4.
• Doctor Who Magazine #254, 30th July 1997, “Archive: The Wheel In Space” by Andrew Pixley, Panini UK Ltd.
• Doctor Who Magazine Special Edition #4, 4th June 2003, “Heroes And Villains” by Andrew Pixley, Panini Publishing Ltd.