K is for... K9

 

Mark I

K9 was originally the personal computer of Professor Marius, of the Bi-Al Foundation. This hospital complex was located in the asteroid belt. Unable to take his real dog there, he had fashioned his mobile computer into a dog-like shape, taking the name K9 from "canine".

It had a powerful blaster in its nose, with a ticker tape outlet beneath, and spoke with a clipped male voice. As well as a gun with different stun or kill levels, the weapon could be used as a cutting or welding tool.

When the Foundation fell under attack by people who had been infected with an alien virus, K9 assisted the Doctor and Leela. The virus was noetic, meaning it targeted intelligence centres and even K9 was temporarily affected by it. After the virus had been destroyed, Marius announced that he was due to return to Earth but weight penalties on the shuttle meant that he would have to leave K9 behind. He was offered to the Doctor. He was uncertain, but Leela was pleased to accept him, and K9 entered the TARDIS.

The robot dog claimed to be much smarter than the Doctor, but as a machine he took things very literally. For instance, when told to forget about something - as in "forget I asked" - K9 took this to mean deleting all information on the subject from his databanks.

K9 accompanied the Doctor and Leela to the dwarf planet of Pluto, and then to a brand new world, which was forming around a spaceship called the P7E. K9 provided a power boost to allow another spaceship - the R1C - to blast free from this new planet before it was destroyed. K9 then visited the Doctor's home planet of Gallifrey. The Doctor used him to trace the home planet of the alien Vardans, helping to expel them and place them in a time loop using access to the Matrix. When Leela elected to stay behind on Gallifrey with Chancellery Guard Commander Andred, K9 opted to remain with her.

Mark II

The Doctor set about programming a new improved version - K9 Mark II - which he had been planning. Almost immediately, the Doctor was sent on a mission by the White Guardian to locate the six segments of the Key to Time. K9 was joined by a new companion - a Time Lady named Romana - for this mission. He was called upon to defend the Doctor and Romana from fierce Shrivenzale creatures, and later fought a duel with a deadly robotic parrot on the planet Zanak - pet of a pirate Captain. K9 proved the victor. The Doctor had now perfected an electronic dog whistle to call K9, unheard by potential enemies.

On the third moon of Delta Magna, the watery environment was such that K9 had to remain in the TARDIS. On the planet Atrios, the planet's military commander tried to get rid of K9 by luring him into a recycling furnace. Later, he was tempted away from the planet by an automated distress signal, and found himself on the neighbouring world of Zeos. Here K9 encountered the super-computer Mentalis, which was running the Zeon war machine. Only K9 could communicate with it.

A fault prevented K9 from encountering the Daleks on Skaro - the robot version of laryngitis - and the Doctor kept K9 in the TARDIS when he and Romana visited the French capital Paris.

K9 later helped defend the Doctor and Romana from Wolfweeds, Mandrels and Nimon.

The robot dog suffered a number of mishaps before leaving the TARDIS to accompany Romana in E-Space. On a visit to Brighton he went into the sea without proper water defences and exploded. The Doctor and Romana had to repair him, but his power packs were prone to running low very quickly after this. On the planet Alzarius K9 had his head knocked off by Marshmen, though the Doctor found that it acted as a sort of totem for the creatures. 

Further damage from exposure to the Time Winds at the point where E-Space and N-Space met meant that K9 could only continue to function in the smaller Exo-universe, which Romana intended to make her new home. K9 stayed with her, informing her that he held complete blueprints for the building of a new TARDIS.

Mark III

When Sarah Jane Smith returned from working abroad she went to live with her aunt, Lavinia, at her Cotswolds home. The contents of her Croydon house had been transferred here, and amongst these was a large crate. This proved to contain a gift from the Doctor - K9 Mark III.

Once activated he helped her rescue her cousin Brendan from Hecate worshippers who planned to sacrifice him to improve their harvests. He also tried to warn Sarah of impending danger when she left for work one day. She failed to heed this - only to be transported to the Death Zone on Gallifrey.

Over time, however, K9's systems ran down. Sarah could not repair him after he deactivated.

When Sarah encountered the Doctor again, at Deffry Vale School in West London, she showed him the defunct K9. He was able to repair him and he helped them to investigate the alien Krillitanes who had infiltrated the school. K9 agreed to destroy the Krillitane by igniting their highly flammable oil in the school kitchens, even though this would destroy himself in the process. Sarah was deeply upset at the loss of her friend.

Mark IV

The Doctor gave Sarah a new K9 model just before he, Rose and Mickey left West London. He claimed to have repaired Mark III, but Sarah realised that he had just given her a whole new model. To begin with K9 was tasked with preventing a Black Hole, created by accident by the CERN project, from destroying the Earth, so was unable to assist Sarah on a regular basis. Whenever he was able to visit the attic, he did not get on well with Sarah's computer Mr Smith, who could be quite jealous.

Once the Black Hole situation had been resolved, K9 took up permanent residence in the attic - much to Mr Smith's annoyance. K9 assisted in getting the Earth back from the Medusa Cascade, where it had been taken by Davros and the Daleks. K9 assisted Sarah and her young friends in their investigations into alien activity. Clyde Langer once tried to cheat on a biology exam by sneaking K9 into the classroom. K9 was invited to attend Sarah's wedding.

When Luke Smith went off to university, Sarah gave K9 to him as a parting gift, so that he could look after her adopted son.

Voiced by: John Leeson and David Brierly (Season 17 only). 

Appearances: The Invisible Enemy (1977) to Warrior's Gate (1981), The Five Doctors (1983),

K9 & Company: A Girl's Best Friend (1981), 

School Reunion (2006), Journey's End (2008), 

The Sarah Jane Adventures (Series 1 - 5).

• K9 was designed by Tony Harding, who was assisting Ian Scoones on the VFX for The Invisible Enemy. Scoones' own attempt looked like an armoured Doberman which could have accommodated an actor inside. The Radio Times would only permit one of the VFX crew to be credited, and producer Graham Williams gave it to Harding due to K9, despite Scoones being the senior.
• According to the Complete History partwork, K9 Mark I was painted a dark gold colour, and only appears grey on screen. K9 Mark II did appear darker in colour, as it was painted a charcoal grey.
• Initially, its remote control clashed with the cameras and it frequently went out of control. Once it was known that it was going to be appearing in more than one story, the VFX team came up with some adaptations, which is why we got K9 Mark II for the following season.
• As K9 couldn't feature in The Power of Kroll, due to the swampy location, John Leeson was able to appear on screen as a new character.
• David Brierly lasted only one season voicing K9, quitting when he was told he couldn't be promised an on-screen role in the show. Brierly only featured on three broadcast stories.
• Terry Nation refused to have K9 meet the Daleks (K9 would have to win, which would make the Daleks look weak), so he did not appear in Destiny of the Daleks. He is confined to the TARDIS with laryngitis - his croaky voice being Roy Skelton on this occasion.
• John Leeson was talked into returning only because he knew that K9 was going to be written out in Season 18. He has voiced K9 ever since - in the revived series, The Sarah Jane Adventures, and the 2009 Australian-made independent production K9 Adventures. 
• This latter series followed the adventures of K9 Mark I, which regenerated in the opening episode into a more cartoon-ish form, capable of flying. How K9 got to leave Leela and Gallifrey was never explained. 
• K9's co-creator Bob Baker attempted other spin-off series and even a movie for him. One movie was officially announced, which would have featured Omega, but nothing ever came of it.
• There is some confusion as to the uniqueness of the original K9. It is implied in The Invisible Enemy that Prof. Marius invented him, yet the Doctor already had a Mark II boxed in the TARDIS before he could have known that K9 was going to stay behind with Leela. When trying to fix K9 in Meglos, the Doctor and Romana use a repair handbook - suggesting that K9 Mark II must have been supplied by a manufacturer and is not unique. The Doctor is also able to come up with Mark IV very quickly.
• Below, K9 at the 2013 Official Convention and the Doctor Who Experience: