The handler and dog must also be able to pass the police test, which involves controlling the dog fully, even after giving the dog the attack command. The dog must stop immediately and fulfill any command it is given by the handler. There are specifications of training involved in using trained K9 police dogs in the airport, marine ports, railroads, in a metro station.
Damaged by the time winds, K9 Mark II could not cross back into N-Space with the Doctor. He decided to stay behind at the Gateway with Romana II to help her free the remaining Tharils from slavery. (TV: Warriors' Gate) Eventually, Romana II and the presumably repaired K9 returned to their own universe and K9 Mark II came to live on Gallifrey. (PROSE: Lungbarrow, WC: Shada, AUDIO: Zagreus)
K9 helped Sarah Jane to defeat Moreton Harwood's murderous Hecate Cult. (TV: A Girl's Best Friend) Circa 1983, K9 Mark III and Sarah Jane lived in semi-detached house where their gate bore a "beware of dog" sign and Sarah Jane permitted him outside unconcealed. Sensing danger, he advised Sarah Jane to either not go out, or to take him with her. She declined, and K9 thus did not accompany her to Gallifrey. (TV: The Five Doctors) K9 accompanied Sarah to an archaeological dig in Egypt. (COMIC: City of Devils) In the early 1990s, K9 assisted Sarah in investigating a supposedly haunted house. (PROSE: Housewarming)

The original K9 model was designed by visual effects designer Tony Harding. One early concept was to have a small actor in a large Doberman-shaped costume; however, Graham Williams vetoed this, saying that the robot should not look like a person in a costume. The eventual design was closely based on Harding's third concept sketch. (DCOM: The Invisible Enemy)

On 24 April 2006, The Independent, the Daily Star and The Times confirmed, following previous rumours, that K9 would be featured in a 26-part children's series, K9, to be written by Bob Baker.[9] The article in The Times also featured a picture of the redesigned K9 for the animated series.[10] The series will be a blend of live-action and a CGI K9.


K9 stayed with Leela on Gallifrey for many years. It was only after the disappearance of her Time Lord husband, Andred, that Leela and her K9 met Romana II and her K9. The two K9s did not get on well and competed. (AUDIO: Weapon of Choice) After Leela became Romana's bodyguard and after many important missions on her behalf, Leela's K9 was destroyed by an exploding bomb. Leela was heartbroken, but refused to have a duplicate unit built. (AUDIO: Imperiatrix)
K9 Mark III was a gift from the Doctor to Sarah Jane Smith (TV: A Girl's Best Friend). This K9 was broken for many years, until he was repaired by the Tenth Doctor. This K9 also had a "maximum defence mode", as well as offensive capabilities, such as a nose-mounted laser gun. He sacrificed himself to save Deffry Vale High School from Krillitanes. (TV: School Reunion)

On 24 April 2006, The Independent, the Daily Star and The Times confirmed, following previous rumours, that K9 would be featured in a 26-part children's series, K9, to be written by Bob Baker.[9] The article in The Times also featured a picture of the redesigned K9 for the animated series.[10] The series will be a blend of live-action and a CGI K9.

K9 returned when Ship used the black hole as fuel. Though Sarah Jane, Luke, Rani and Clyde were happy to have K9 back, Mr Smith was not. (TV: The Mad Woman in the Attic) K9 spent a lot of his time in Sarah Jane's attic at 13 Bannerman Road, Ealing, but left to defeat Travast Polong. He attended Sarah Jane's abortive wedding to Peter Dalton, where he helped the Tenth Doctor, Luke, Rani and Clyde defeat the Trickster. (TV: The Wedding of Sarah Jane Smith) After helping defeat the Slitheen family, Clyde brought K9 to Park Vale Comprehensive School to help him with his test. He helped defeat the Rakweed before returning home. (TV: The Gift) K9 went to the University of Oxford with Luke, but restored Mr White's original programming through a mobile phone.(TV: Goodbye, Sarah Jane Smith)
Professor Frederick Marius, who invented the first K9 in the year 5000 while working on the asteroid K4067, described him as "my best friend and constant companion." Marius had a dog on Earth, but weight requirements did not allow him to bring his real dog into space, so he built K9. (TV: The Invisible Enemy) He built K9 by using the latest technology. Marius used his own medical computer, a state-of-the-art intraresponsive brain app, protective anti-radiation cladding, probes, a laser scapel, a vision and voice box and two scanning antennas. He put these parts together and created K9. (PROSE: One Man and His Dog) According to one account, the Professor copied the remnants of one of the versions of K9 created by the Doctor and given to Sarah Jane Smith. (PROSE: Tautology)
Despite those drawbacks, K9 comes with a handful or so of predesigned filters and an option to customize. With more than 50 categories for organizing Web sites, and the keyword-free proprietary K9 rating system, the Web monitoring and blocking aspects of the software functioned well. K9 also has categories for blocking sites that have been detected as potential malware threats. Equally impressive, and a little bit scary, was the log that detailed not just blocked Web sites but also every Web site visited.

To run the program, you must register on the Web site to get the free activation code. The control panel is accessible only through the Internet. Uninstalling requires removing the app from the Task Manager, then using its password to delete it from the Windows Control Panel, and finally, rebooting. Because the password gets sent to the e-mail account of the person who registered the program, it's possible that an enterprising user could disable K9 on a shared computer.


K9 Mark I was created about the year 5000 by Professor Frederick Marius, who gave the dog to the Fourth Doctor and Leela. He was left behind with Leela on Gallifrey. (TV: The Invasion of Time) Some time later, he was blown up by a bomb on Gallifrey, (AUDIO: Imperiatrix) but survived. This model came to an end when Alistair Gryffen's Space-Time Manipulator randomly pulled him to London in the year 2050. There, he almost immediately self-destructed to protect Gryffen and a group of teenagers from Jixen warriors. (TV: Regeneration)
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, K9 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 K9 on a secret mission to Espero, presumably to seek out his former companion, the living TARDIS known as Compassion.
×