Beings from space arrive in England, calling themselves Axons. They bring with them a fantastic substance called Axonite which can affect the structure of matter. The Axons offer to exchange the Axonite with the various world powers, but the Doctor discovers there is something sinister about the aliens -- not the least of which is their secret allegiance with the Master.

Bob Baker and Dave Martin had both held a variety of jobs before getting into writing for television in the late Sixties. One of Baker's skills was animation, and the pair -- who would become known as “the Bristol Boys” -- tried to interest the BBC in this material. Soon thereafter, they began writing plays for telecast, and developed a sitcom entitled A Man's Life, the script for which ended up on the desk of Doctor Who script editor Terrance Dicks. Dicks, his assistant Trevor Ray, and producers Derrick Sherwin and Peter Bryant met with Baker and Martin and asked the duo to submit an idea for Doctor Who.

The storyline conceived by Baker and Martin was a seven-part adventure featuring Patrick Troughton's then-current Second Doctor, entitled “The Gift”. It involved evil aliens who land in Hyde Park in a skull-shaped spacecraft, and featured spaceship battles and even a giant carrot crashing into the park. “The Gift” was scaled back to six installments by the time the script for episode one was commissioned on December 1st, 1969, by which point Jon Pertwee had been cast as the new Doctor. However, the script was not submitted to the production office until April 6th, 1970 -- more than three months past the original delivery date of January 2nd -- and failed to meet the approval of incoming producer Barry Letts. Letts felt that “The Gift” was too much of a jumble of ideas, and was unhappy with the skull spaceship image. The script also seemed to overestimate what could be accomplished on the limited Doctor Who budget.

After talking things over with Dicks on the 6th, Baker and Martin received a commission for a revised version of the storyline, now called “The Friendly Invasion”. This time around, the pair sought to exploit the idea of the aliens appearing to be philanthropic while secretly scheming to destroy the Earth. However, Letts and Dicks still felt that “The Friendly Invasion” was too full of disparate ideas and Dicks thereafter worked closely with the writers to rein in their exuberance.

Baker and Martin were also asked to insert the Master into their storyline. This character had been designed by Letts and Dicks to be the Doctor's new archfoe, and was being included in every story of Doctor Who's eighth season. Baker was displeased with this remit, as he did not feel that the Master fit well in the established plot. The adventure's title became “The Axons” at about this stage; this was the name of the evil aliens, which was inspired by the term for the nerve fibre along which neurological impulses are carried. The serial's length was also pared back to four episodes. By this time, it was thought that “The Axons” would be the third story of Season Eight, earning the production code GGG.

The script for part one was commissioned on September 11th, followed by part two on October 18th and the remaining installments on the 29th. It was Dicks' idea that the interior of Axos should appear organic rather than man-made, and that Axos would drain the life out of the surrounding countryside. The use of Axonite was to have been demonstrated using a rat instead of a toad; the scripts also indicated that Winser's first name was Malcolm.

In mid-December, the title was changed again to “The Vampire From Space”. This was felt to be more Doctor Who-ish, although the production office was not happy with the term “vampire” being used. Michael Ferguson was assigned to direct the story, having most recently worked on the programme on The Ambassadors Of Death one year earlier. It was decided that Fernanda Marlowe would reprise the role of Corporal Bell which she had originated in the previous serial in production, The Mind Of Evil. Bell replaced a scripted “UNIT R/T Man”; this would be the character's second and final appearance.

All location work on Serial GGG took place in Kent, beginning on January 4th, 1971 at Dengemarsh Road in Lydd for some roadside scenes. More of these, as well as all the Axos exterior material, was recorded on the 5th and 6th at nearby Dungeness Road. Yet more road sequences, most notably the fight between Yates and Benton and the Axons, were then filmed on the 7th at St Martin's Plain Camp in Shorncliffe. January 8th took cast and crew to the Dungeness ‘A’ Nuclear Power Station in Dungeness, which served as the Nuton Power Complex.

Frustratingly, the weather proved highly variable throughout the five-day shoot, ranging from snow at the start of the week, through fog and finally to sunshine on the final day. To explain the inconsistency, Dicks assigned a new line of dialogue to Corporal Bell which noted that Axos' arrival had prompted “freak weather conditions”. Some model filming was also completed for the story.

The first studio session took place on Friday, January 22nd and Saturday the 23rd in BBC Television Centre Studio 3. These two days were used exclusively for scenes from the first two episodes, with material set in UNIT HQ and the Mobile HQ recorded on the Friday, and the remainder of the material scheduled for the Saturday. This included the debut of the new TARDIS console, designed by Kenneth Sharp. The original had been tinted light green to show up better as white on monochrome videotape, but was no longer suitable now that Doctor Who was being broadcast in colour. It had also been badly damaged over its seven years of service.

Unfortunately, complicated effects work meant that time ran out on the final scenes of part two, set in the Nuton Complex. These had to be rescheduled for the second recording block, which occurred exactly two weeks later on February 5th and 6th, albeit in TC4 this time. The Friday was dedicated to episode three (as well as the remaining material from part two), while episode four scenes were taped on the Saturday. The serial's title also underwent one final evolution at this time, to The Claws Of Axos. The late change meant that the opening credit sequences for the first two installments had to be rerecorded on the 6th, and the original title was inadvertently retained on some overseas prints as well as in most of the story's publicity material.

The Claws Of Axos was the last of Michael Ferguson's four directorial outings on Doctor Who. He went on to helm episodes of programmes such as Colditz before becoming a producer, with credits including The Sandbaggers, EastEnders and Casualty.

• Doctor Who: The Handbook: The Third Doctor by David J Howe and Stephen James Walker (1996), Virgin Publishing, ISBN 0 426 20486 7.
• 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 #264, 6th May 1998, “Archive: The Claws Of Axos” by Andrew Pixley, Panini UK Ltd.
• Doctor Who Magazine Special Edition #2, 5th September 2002, “Something Old, Something New” by Andrew Pixley, Panini Publishing Ltd.