An Earth spacecraft has crashlanded on Dido in the year 2493, and most of its crew has been murdered by the planet's denizens. The only survivors are Bennett, crippled and bedridden, and an orphaned girl named Vicki. They are now being terrorised by the monstrous Koquillion while they wait for a rescue ship to arrive. When the TARDIS lands on Dido, the Doctor expects to meet a peaceful native race, and is baffled that the planet seems all but deserted. When Koquillion tries to kill them, the time travellers become determined to discover his true motives, and his real identity.

Doctor Who producer Verity Lambert and story editor David Whitaker had planned since at least May 1964 to make changes to their lead cast should the programme be renewed for a second recording block. When the Controller of Programmes for BBC One, Donald Baverstock, finally granted Lambert thirteen more weeks of Doctor Who on August 14th, Lambert quickly set about finalising plans to write out Carole Ann Ford's Susan in the concluding episode of The Dalek Invasion Of Earth, the last story of the first production block. Her replacement would be the freedom fighter Jenny, introduced in the same story.

In the wake of Doctor Who's renewal, however, Lambert was confronted by various contractual demands from her remaining stars. This cast a shroud of uncertainty over the programme's future yet again. Consequently, on August 19th, Lambert decided not to install Jenny as the new companion, although Ford would still exit the programme as previously planned. Instead, the new companion -- who, like Susan, would be a teenaged girl -- would debut in the first serial of the new recording block. This gave Lambert time to work out the issues raised by William Hartnell, William Russell and Jacqueline Hill. In the process of settling their contracts, Lambert was also able to get a guarantee of another thirteen weeks from Baverstock; talk of Doctor Who being cancelled in favour of a different show was put to rest entirely.

David Whitaker agreed to introduce the new companion as a coda to his regular involvement in Doctor Who

By this time, Whitaker had made it known that he would be leaving his post as story editor as of October 31st. His successor was Dennis Spooner, who had already written The Reign Of Terror and who was now working on the second story of the new recording block, The Romans. Around late August, Whitaker agreed to write a two-part adventure that would introduce the new companion. This coda to his regular involvement in Doctor Who would be his second set of scripts for the show, following Inside The Spaceship. Although Whitaker's serial would be the first to be made as part of the second production block, it would be the third of Doctor Who's new season, since both Planet Of Giants and The Dalek Invasion Of Earth were being held over.

Names that Whitaker initially considered for the new character included Valerie and Millie. The latter was inspired by pop star Millie Small (whose version of My Boy Lollipop had peaked at number two in the UK charts following its release in May), but was rejected because of its association with well-known comedian Millicent Martin. Whitaker then settled on the name Tanni, which gave the story its working title. The formal commission for “Tanni” did not come until November 1st, following Whitaker's official departure from Doctor Who.

On September 14th, camera tests for the part of Tanni were held, with two actresses present. Television newcomer Maureen O'Brien won the role over Denise Upson, who had appeared in an installment of ITV Play Of The Week. O'Brien was contracted for her introductory story, as well as The Romans and The Web Planet, on October 9th. A few days earlier, on September 30th, O'Brien's co-stars had also been formally contracted for the same serials, plus The Crusade.

A rather private individual, O'Brien was happy to heed Lambert's request to keep her casting a secret until an official BBC press release. She was therefore shocked when a number of reporters descended on her Liverpool home one morning; O'Brien subsequently discovered that her parents had naively mentioned the good news to a friend, who gave the story to the newspapers. The official announcement of Doctor Who's new castmember ultimately came on November 10th, with a photocall held the following day.

Meanwhile, the new companion continued to be developed over the break in production during the autumn of 1964. The name Tanni was discarded, and O'Brien's contract used “Susan” as a placeholder. By November 12th, Lambert's preference was Lukki (pronounced “Lucky”). On November 20th, the character finally became known as Vicki, although the spelling “Vikki” may also have been considered. Around the same time, the serial's title was amended to The Rescue. Another significant change involved the weaponry wielded by Koquillion. As Whitaker had originally envisaged his first confrontation with Ian and Barbara, Koquillion was to use a device which forced the schoolteachers to answer his questions truthfully and obey his commands. He tried to use them to lure the Doctor out of the TARDIS, but their awkward speech patterns tipped off the Doctor that something was amiss.

The Rescue was made by the same team as The Romans

Given the brevity of The Rescue, it was decided that it would be made by the same team as The Romans, working under director Christopher Barry. A year earlier, Barry had been responsible for most episodes of The Daleks. Filming for The Rescue began on November 16th and 17th, when the serial's model shots were captured at the BBC Television Film Studios in Ealing, London.

As with the first production block, the new slate of episodes would be recorded on consecutive Fridays, with Doctor Who returning to Riverside Studio 1 in Hammersmith, London. The first installment of The Rescue, The Powerful Enemy, was taped on December 4th, reuniting Hartnell, Russell and Hill after a six-week break. O'Brien was initially nervous about joining such a well-established ensemble, but was reassured following a visit by Carole Ann Ford, who dropped by on the first day of rehearsals to wish the new castmember good luck. O'Brien quickly developed a rapport with Hartnell, finding herself a calming influence when his temper began to fray.

Episode two, Desperate Measures, was taped on December 11th. An accident occurred during the sequence in which Barbara shot the sand monster, Sandy, with the flash charge in the pistol discharging prematurely. Jacqueline Hill was badly startled, and suffered some facial discomfort. When the scene was remounted, a flash charge was detonated on the set near Sandy, instead of in the gun prop itself.

The Rescue was the first Doctor Who story to make use of an alias in the end credits in order to avoid spoiling the plot. Specifically, the secret of Bennett's dual identity was preserved by listing Koquillion as being played by “Sydney Wilson”, rather than by Ray Barrett, at the end of The Powerful Enemy. The pseudonym was derived from the names the BBC's Heads of Drama and Serials -- respectively, Sydney Newman and Donald Wilson -- both of whom had been driving forces behind the initial development of Doctor Who.

Although The Dalek Invasion Of Earth had drawn record audiences for Doctor Who, The Rescue managed to better it. On January 9th, 1965, Desperate Measures became the first episode to reach eighth place amongst the week's programmes. It would not be the last time Doctor Who would attain such lofty heights.

• Doctor Who Magazine #325, 8th Jan 2003, “Archive: The Rescue” by Andrew Pixley, Panini Publishing Ltd.
• Doctor Who Magazine Special Edition #7, 12th May 2004, “I'm Into Something Good” by Andrew Pixley, Panini Publishing Ltd.
• Doctor Who: The Complete History #4, 2017, “Story 11: The Rescue”, edited by Mark Wright, Hachette Partworks Ltd.
• Doctor Who: The Handbook: The First Doctor by David J Howe, Mark Stammers and Stephen James Walker (1994), Virgin Publishing.
• Doctor Who: The Sixties by David J Howe, Mark Stammers and Stephen James Walker (1992), Virgin Publishing.