K-9, or K9, is the name of several fictional robotic dogs in the long-running British science fiction television series, Doctor Who, and its spin-off series, The Sarah Jane Adventures. There have been at least four separate K-9 units in the series, with the first two being companions of the Fourth Doctor. Voice actor John Leeson has provided the character's voice in most of its appearances, except during Season 17, when David Brierley temporarily provided the voice. K-9's most recent appearance was in the episode "Journey's End", the finale of series four. All four of the K9 models have the same catchphrase which is "Affirmative".
A new television series starring K-9, K-9, is currently in development and is planned to air in 2008.
All the K-9s referred to whoever owned them as "Master" or "Mistress" depending on their gender. The units were programmed to be both loyal and logical, with a penchant for taking orders literally, almost to a fault. The Fourth Doctor would often use a glib remark to disarm those who were surprised by K-9's appearance; in The Stones of Blood he said, "They're all the rage in Trenton, New Jersey." The Tenth Doctor defended its less-than-streamlined design ("...so disco!") to Rose Tyler, remarking that it was cutting edge in the year 5000.
To date, four different versions of K-9 have appeared in the series:
The practical challenges of working with the K-9 prop have accompanied the robotic pooch in his return to Doctor Who. Producer Russell T Davies told SFX magazine, "Yes, just as we expected, multiple takes when he bumped into a door or veered off to the left. Lis Sladen did warn us, and she was right!
In the 1998 computer game Fallout 2, the Navarro base has a damaged robot dog known as K-9, which uses similar speech mannerisms to the Doctor Who character. If repaired, the cyberdog is willing to join the character's party as a companion.
In the 1999 television series Queer as Folk (written by current Doctor Who executive producer Russell T Davies), a K-9 model is given to the character Vince as a birthday present. The prop used was an original, operated — as occasionally in Doctor Who — by visual effects assistant Mat Irvine.
In the South Park episode "Go God Go XII", Eric Cartman, being trapped in the year 2546, has acquired a robot dog called "K-10", a parody of K-9. Due to timeline alterations, he is replaced by robot cat "Kit-9" and later robot bird, "Cocka-3".
Engineers at NASA's Ames Research Center have dubbed two intelligent mobile robots designed to explore the surface of Mars "K-9" and "Gromit". NASA's K-9 is named after both Doctor Who's K-9 and Marvin the Martian's pet dog.
In the second series of I'm Alan Partridge, the character of Alan Partridge recalls how his purchase of the rights to K-9 assisted in him mentally breaking down and driving to Dundee in his bare feet while gorging on Toblerone.
K-9 appeared on a 2007 Doctor Who special edition of The Weakest Link, but was voted out unanimously at the end of the first round, despite answering all of his questions correctly. Anne Robinson (whom K-9 addressed as "Mistress") said "I'm so sorry" before declaring him the weakest link.
When Romana eventually returned to her own universe, she brought K-9 Mark II with her (presumably having repaired it) and eventually became Lady President of Gallifrey. K-9 Mark II is first seen on Gallifrey in the Virgin New Adventures novel Lungbarrow by Marc Platt, alongside K-9 Mark I, which had remained with Leela. Both K-9 Mark I and Mark II appear, voiced by Leeson, in the Big Finish Productions audio adventure Zagreus and the Gallifrey audio series. Leela's K-9 (Mark I) was destroyed at the conclusion of the second Gallifrey series and only Mark II appears in the third series.
In 1985, a series of gamebooks featuring the Sixth Doctor were published by Severn House under the title Make your own adventure with Doctor Who in Britain and Find Your Fate — Doctor Who in the United States. These books were actually written by scriptwriters for the television series. Martin wrote Search for the Doctor which takes place in the mid-21st century and features K-9 Mark III being reunited with the Sixth Doctor long after Sarah's death.
A short story, Moving On, in Virgin Publishing's Decalog 3: Consequences anthology and the Big Finish Productions-produced Sarah Jane Smith audio play Mirror, Signal, Manoeuvre (both written by Peter Anghelides) indicate that K-9 Mark III broke down and Sarah was unable to repair it as the replacement circuits would not be invented for several centuries.
Another short story, Tautology, by Glenn Langford (Doctor Who Magazine #194), suggests that K-9 Mark III's motherboard will be passed down through Sarah's descendants and eventually end up in the hands of Professor Marius, who will use it to build the first K-9, creating an ontological paradox.
Jealous, Possessive by Paul Magrs, the "Scorpio" story in Big Finish's anthology Short Trips: Zodiac features K-9 Mark I and Mark II relaying their exploits to each other, and their veiled put-downs to each other reveal that each considers the other to be the "inferior" version. This attitude is also occasionally hinted at in the way the two units refer to each other in the Gallifrey audio series.
The Eighth Doctor Adventures novel Interference: Book Two by Lawrence Miles indicates that the Doctor built a Mark IV model sometime prior to the events of that book, but what happened to this unit is not stated. In the novel The Gallifrey Chronicles by Lance Parkin, K-9 Mark II makes another appearance, having been trapped within the TARDIS since the events of The Ancestor Cell. At the end of The Gallifrey Chronicles the Doctor sends K-9 on a secret mission to Espero, presumably to seek out his former companion, the living TARDIS known as Compassion.
The canonicity of the spin-off stories is unclear, especially in light of K-9 and Sarah's return.
On April 24 2006 The Independent, the Daily Star and The Times confirmed, following previous rumours, that K-9 would be featured in a 26-part children's series, K-9, to be written by Bob Baker. The article in The Times also featured a picture of the redesigned K-9 for the animated series. The series will be a blend of live-action and a CGI K-9.
Each episode will be 30 minutes long, made by Jetix Europe and London-based distribution outfit Park Entertainment. According to a report in Broadcast magazine, the BBC opted out of involvement in order to focus on their own Doctor Who spin-off, Torchwood, meaning that BBC-owned characters are unlikely to appear in the series. A broadcast date for the series has not been officially announced, but a 2008 debut is planned.