K-9 and Company is a one-episode television pilot, for a proposed 1981 television spin-off of the British science fiction television series Doctor Who. It features former series regulars Sarah Jane Smith, an investigative journalist played by Elisabeth Sladen, and K9, a robotic dog voiced by John Leeson. Both characters had been companions of the Fourth Doctor, but they had not appeared together before. The single episode, “A Girl’s Best Friend”, was broadcast by BBC1 as a Christmas special on 28 December 1981, but was not taken up for a continuing series.
“A Girl’s Best Friend” is set in the fictional English village of Moreton Harwood in 1981. In the programme, Sarah and K9 investigate the disappearance of Brendan Richards (Ian Sears), the ward of Sarah’s Aunt Lavinia (Mary Wimbush), in the wake of increasing reports of witchcraft.
Under a different production team, the overall concept of a Sarah Jane and K9 series did eventually come to fruition: The Sarah Jane Adventures (2007–2011), featuring both of these key characters and actors (though K9 and Leeson only appear in some episodes).
The programme has its roots firmly in the desire of Doctor Who producer John Nathan-Turner to get Elisabeth Sladen back into the TARDIS. He wanted her to have the contract eventually awarded to Janet Fielding in late 1980. John Nathan-Turner’s preferred plan for the transition from Baker to Davison was to have Sarah Jane be along for the ride from Logopolis to the second story of series 19. However, Sladen had no interest in returning simply to reprise a role and function identical to the one she had left years before.
Meanwhile, Nathan-Turner was trying to figure out what to do about K9. The robot dog was very popular among children but was difficult to deal with technically and Nathan-Turner felt that it made the TARDIS crew almost overwhelmingly formidable. He decided that a child-orientated spin-off series with K9 might be just the thing. However, such a series would require a human as the lead, and his prime candidate for this role was Sladen. He pitched the part to the actress as a departure from what she had previously done: she would be returning as Sarah Jane Smith, but she would do so as the heroine and not just a sidekick. This offer Sladen accepted.