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Affirmative, Master

All you ever wanted to know about K9

By Jon Preddle

Love him, or hate him, K9 is as much a part of Doctor Who as is the sonic screwdriver, the TARDIS and jelly-babies. K9 first appeared on British TV on 8 October 1977, and went on to become the Doctor's longest-running companion. This article looks at the creation of K9, details the TV stories that K9 appeared in, and then lists the merchandise aspects of the character.

Behind the Scenes

Originally called F1D0, K9 was created as a one-off character by writers Bob Baker and Dave Martin for the Season Fifteen serial The Invisible Enemy. It has been said that they were inspired by the robots of Star Wars however the time factor between when the script for The Invisible Enemy was written and the release of Star Wars in Britain clearly shows that K9 was created well before R2D2 and C3PO appeared on the scene.

In terms of the story K9 was the computer pet of Professor Marius who built the robot dog to replace the real pet he had to leave behind on Earth because of the weight restriction on the shuttle from Earth to the Bi-Al Foundation. In the script, K9 was simply described as a 'personal Komputa [sic] which is like a tin dog on wheels', and was envisaged by Baker and Martin to be 'performed' by a midget actor in a dog-shaped suit. The effects designer assigned to this story, Ian Scoones, did a series of preliminary sketches, the first of which looked somewhat like a fierce armoured doberman, but due to the heavy workload of miniatures requirements for the serial, he had to hand the final design and building of K9 to his assistant, Tony Harding.

Harding had only two weeks in which to draw up plans for the machine; his main brief that it should not look as if there were a man was inside. This meant that 'the Dog' (by which the production crew affectionately referred to K9) had to be remote-controlled.

Harding's first design sketches were not that different from K9's eventual look. From this a rough form test model of the basic shell was made, After assessing the different requirements the Dog needed to perform for the story; e.g. tail wagging, head movement, gun and probe etc, it was realised that the motor for these functions would have to be housed in the head. The original molded head therefore had to be made larger to incorporate all the electronics for this. Once the final shell was made, the electronics could be fitted. The mechanics of K9 included rotating ear-probes, telescopic 'eye' probe, extendable nose, flashing lights on the top and the 'eye' panel, waggling tail antennae, and ticker-tape tongue. The head could also move up and down. The shell was painted in gold/grey metallic. Around K9's neck was a tartan collar, from which hung a silver disk. Surprisingly there was nothing engraved on the disk, not even K9's name!

K9 was operated by effects man Nigel Brackley using a Futaba radio-control unit. The chassis housed his battery power source, servos, and motor. One of the two steerable front wheels was connected by the chain drive to the motor. One major problem with K9's radio-control was that it operated on the same wave-length as the studio cameras, causing several delays in the studio when K9, receiving jumbled signals from the cameras, went in the wrong direction and crashed into the set! K9 was originally driven by a chain-drive. Unfortunately, this was rather noisy to the extreme that composer Dudley Simpson was forced to compose loud incidental music for scenes that featured K9. One example of this is in The Sun Makers, where K9 is 'sneaking silently' up to a guard. We, the audience, can hear the loud whine of the motor, and the crashing music while the guard stands completely unaware of the 'danger' behind him!

Producer Graham Williams realised the potential for K9 to become a long-serving member of the TARDIS crew shortly before The Invisible Enemy went before the cameras. Tony Harding once said that had he known beforehand that K9 would become a permanent feature on Doctor Who he would have designed it totally differently. Contrary to popular belief, there were not two different endings recorded for The Invisible Enemy. The original script ended with the destruction of Titan, the Doctor, Leela and K9 heading back to the Bi-Al Foundation, presumably to return K9 to Marius. However, Williams insisted that a tag scene showing K9 being given to the Doctor be added during recording of the serial.

Including K9 in the TARDIS line-up proved a minor headache for script editor Robert Holmes. At the time of The Invisible Enemy's recording (it was the first story recorded for the season but broadcast second) most of the other scripts for the season were being written - and none of them featured K9. So, while the first serial of the season, Horror of Fang Rock, was in the studio (it was recorded after The Invisible Enemy), Holmes was busily amending scripts to accommodate K9, either including the machine, or providing an explanation for its non-appearance.

In terms of TV continuity there have been three separate K9's but in reality, there has been only one, but which has been repainted and re-built several times over the years. K9 Mark One was written out of the series in The Invasion of Time, staying behind on Gallifrey to look after mistress Leela. There was an ulterior motive for this. The special effects designers wanted to rebuild K9 during the recess between seasons. It would have been a cheat to not explain the difference in K9's appearance in the opening story of the following season, so a simple scene where the Doctor produces a box containing the components for a new K9 was added to the end of The Invasion of Time.

While the shell remained the same, the interior was changed. This new K9 was given a rubber belt in place of the chain drive. Valuable studio time was still lost, however, because the drive-belt tended to snap.

While the cosmetic changes were minimal (including the new metallic charcoal paint-work), in terms of series continuity K9's character underwent a vast change. Gone was the product of 5000 AD technology, as was the case with Marius's version. This new K9 was a product of the Doctor's own technology and values. The gun was now only capable of stunning - not killing - and K9 now responded to a dog-whistle. K9 also featured a vast memory-bank, seemingly a mixture of the Mark One model, the Doctor's own memory and knowledge, and that of the TARDIS.

Also built around this time was a light-weight duplicate shell. This manageable prop was a necessity for scenes where K9 was to be carried by actors because the motorised version was far too heavy. Unfortunately in some shots, such as Warriors' Gate for example, the fact that an 'empty' prop is being carried is all too obvious! Since K9 was originally designed only for use in the television studio, when it came to location shots, further problems arose. Although the Mark Two K9 had a stronger motor, on its first location filming for The Stones of Blood, it still had to be either placed on hidden tracks or pulled along with string. So much for an improved drive-system!

The second K9 lasted until the end of Season Seventeen. The main operator was Nigel Brackley, who handed the task onto Mat Irvine for Season Eighteen. Before recording for the new season started, Irvine and his assistant Charlie Lumm undertook a complete overhaul on K9 which was why he was written out of the main story in the opening Brighton beach scene of The Leisure Hive to allow them time to work on the machine.

The entire inner workings were stripped once again and over two weeks a new drive and power system were installed. The new mechanics of K9 included larger wheels in conjunction with a front and back-wheel drive, while the radio-control was updated to a more reliable FM model. This 'semi-new' K9 was ready for use in the second story to be recorded, State of Decay, and was last seen in Warriors' Gate.

A year later, K9 was given a brand new coat of paint (this time a metallic-blue) plus a handle on the top of the shell to make carrying him easier, for his appearance in the K9 and Company pilot, A Girl's Best Friend. This same version later appeared in The Five Doctors in 1983.

K9's distinctive voice was first provided by actor John Leeson. Recording of the voice was done 'live' in the studio, with Leeson usually seated in a sound booth close to the main set. However during rehearsals he would 'play' K9 by crawling around the floor on his hands and knees! For The Invisible Enemy Leeson's voice was treated with a modulator to give it a more mechanical lilt, but for subsequent stories he was able to provide the required distortion naturally.

The swampy location used for The Power of Kroll meant that K9 could not be used. This break enabled John Leeson to appear in the flesh for the first and only time on Doctor Who, as Dugeen, one of the refinery crew.

Not wanting to be identified as only a voice artist Leeson left at the end of Season Sixteen, having performed K9's dialogue for nine stories. For the three stories in which he appeared in Season Seventeen (as well as the aborted Shada) actor David Brierley provided a similar but distinctly different voice. This new voice was explained with an inserted line of dialogue in Destiny of the Daleks - K9 had developed laryngitis!

When John Nathan-Turner took over as producer for Season Eighteen, he was able to coax John Leeson back for that season on the guarantee that K9 was to be written out at the end of the season. Part of this contract also extended to the spin-off special, K9 and Company.

In June 1980 when the news broke to the press that K9 was leaving the series during the Eighteenth Season The Sun newspaper launched a 'Save K9 Campaign' which invited the nation's children to write to the BBC demanding K9's return. The campaign was only mildly successful; producer John Nathan-Turner discussed with Baker and Martin the possibility of setting K9 in his own series of animated shorts. Whilst the animated series never eventuated the collaboration resulted in K9 and Company (originally called Sarah and K9).

K9 and Company was recorded at the same time as Season Nineteen (in tandem with Earthshock), and there were hints at the time that K9 would return to the series during Peter Davison's first full season. A script co-written by Bob Baker titled The Return of the Beast or The Beast's Return was apparently in the works.

After K9 and Company K9 made guest appearances on The Generation Game and The Computer Programme as well as attending several conventions and functions. After The Five Doctors in 1983, K9 virtually disappeared from the TV screens until the 1990 Search Out Science programme on space. The special also featured Sylvester McCoy and Sophie Aldred in their respective TV roles. In 1993 K9 (now sporting a metallic-blue coat of paint) once again joined with the Seventh Doctor in a small cameo in the Children in Need special Dimensions in Time. Mat Irvine had taken the opportunity to once again improve K9's workings between appearances, each time using more sophisticated components.

K9 was once a feature at the Longleat Doctor Who exhibit, and he also appeared in Madame Tussaud's Wax Works in 1980 with Tom Baker's wax model. A version of K9 resided in London's Museum Of the Moving Image ('MOMI').

The Stories

The Invisible Enemy: K9 was built by Marius to replace the real dog he left on Earth. K9 knows everything Marius does- and more. He has a photon laser beam with four settings (with a red laser beam effect). He has no emotional circuits and responds to the verbal signal 'Kalaylee', the meaning of which is never revealed. K9 is affected by the Nucleus and switches himself off to go into self-regeneration mode. When Marius has to return to Earth he cannot take K9 with him, so K9 chooses to stay with the Doctor and Leela.

Image of the Fendahl: The Doctor finds corrosion in one of K9's circuits, temporarily shutting him off. One of the side panels is removed exposing internal workings. The Doctor says K9 is his dog.

The Sun Makers: K9 is programmed to play chess and beats the Doctor. He knows of the planet Cassius. K9 can withstand the pressure in the steam room and can read the Doctor's body aura.

Underworld: The Doctor declares K9 to be his second best friend! K9 suffers a blaster malfunction in this story. His probe is able to date the objects in the storage room on the R1C and he can identify ion drive in space. Attached to the R1C computer by bulldog clips on his 'ears', K9 can pilot the ship. He prints out a cut-away map of the tunnels.

The Invasion of Time: The Doctor declares K9 to be his second best friend again. K9 confirms he is not programmed for emotion. He communicates with TARDIS via his probe connecting with the console plinth, and thinks the TARDIS is 'very stupid'. K9 probes into Doctor's mind and links with the Matrix via the coronet and the sash. He elects to stay on Gallifrey to be with Leela.

The Ribos Operation: The Doctor tests the new K9 Mark II's response to an ultra-sonic dog whistle. This K9 has at least seven modes of stun (but cannot kill). The new K9 is able to attach itself to the TARDIS console and pilot the ship, and can detect the Doctor's brain pattern. It would be assumed that this K9 is more advanced than Marius' version having been constructed with the Doctor's greater technological skills and knowledge.

The Pirate Planet: K9 is affected by the Mentiads' power, causing him to spin (see also The Armageddon Factor). He can analyse precious stones and traces psycho-spore as well as the Doctor's heart-beat. He also has a built-in seismograph. After battling with the Captain's parrot K9 is low and recharges his batteries by connecting to a power cable. He sends out a frequency to jam the Captain's mind-jammer. K9 can pilot an air-car.

The Stones of Blood: K9 has knowledge of lawn and table tennis. When Romana instructs him to 'forget it' he erases the sport from his memory! His power is exhausted after 17 minutes. The Doctor tells Emelia Rumford that computers like K9 are all the rage in Trenton, New Jersey! K9 is later smashed by Ogri and his cerebral core severely damaged, Doctor tries to revive him with mouth-to-mouth! Romana connects K9 to the TARDIS regeneration circuits and he is fixed as good as new. K9 can detect Romana's tissue and alpha-wave patterns. He creates a force-field to keep the Ogri at bay.

The Androids of Tara: K9 is programmed with all chess games since 1886, and can beat the Doctor. He has cutter-ray, stun and blaster modes in his laser, and he can detect androids.

The Power of Kroll: K9 is marooned in TARDIS because of swamps. He is not seen or heard in this story.

The Armageddon Factor: His sensors can be blocked by lead-shielding. The Marshall orders that K9 be thrown into furnace to be melted into scrap. K9 shuts himself down when the temperature gets too high. K9 communicates with Mentalis using computer 'burble'. While communicating with the Zeos computer K9 spins around. The Doctor comments that he has never seen K9 do that before - however K9 did something similar in The Pirate Planet while the Doctor and Romana both watched! With a control box placed under his chin. K9 falls under the Shadow's power. It was while in this state that K9 refers to the Doctor as 'Doctor' instead of 'Master', his usual form of address. K9 has two small sliding panels in his side (which are not present in other stories!) used by the miniaturised Doctor and Drax to hide inside K9.

Destiny of the Daleks: K9 gets laryngitis and the Doctor can't understand what he needs it for! The Doctor has disconnected his computer brain to find the cause, but fails to put arrow 'A' to the front causing K9 to spin around. (K9 was deliberately written out of this story at Terry Nation's insistence; he did not want the dog to overshadow his Daleks, and the production team wanted to avoid a K9 vs Daleks confrontation, which they deemed would look silly!)

City of Death: Although K9 does not actually appear in this story the Doctor greets him when he enters the TARDIS in Part Two.

The Creature from the Pit: K9 now has a new voice, a result of his bout of laryngitis. He can read. K9 gets covered in wolfweed web. Adrasta wants K9 to kill the creature but K9 is not programmed to kill except in self-defense. He uses a vast amount of ticker-tape at one point! K9 declares he is not made from tin!

Nightmare of Eden: K9's welding beam is blue. His sensors do not work in the interfaces between ships, although he can pass through them otherwise unaffected. The Doctor connects K9 to the CET via his ear probes.

The Horns of Nimon: When the TARDIS explodes. K9's head is jarred upside down! The Doctor gives him mouth-to-mouth. When K9 analyses the TARDIS damage circuits the Doctor finds him buried under a massive pile of ticker-tape. The Doctor now considers K9 to be his best friend and awards him a 'First Prize' rosette. K9 knows of Skonnos. He gets blasted and partially dismantled by Soldeed. Sorak reassembles him. He is able to compute an exit from the labyrinth.

Shada: K9 does not appear until Part Two. He monitors Chronotis's life signs and detects the babble of voices. His stun beam is used to fight off the Krargs. He is able to determine Skagra's origins.

The Leisure Hive: K9 has a record of all leisure planets in the Galaxy. Romana throws her beach ball into the sea and K9 goes to fetch it, exploding in the process!

Meglos: Romana and the Doctor complete repairs to K9 after his 'swim'. He even has a manual which would have been written by the Doctor. The book is seen propping up the hat-stand! Romana un-jams his probe circuits by waggling his tail. He is very low on power and switches off for a while, spending part of the story hidden in the jungle. Grugger kicks him.

Full Circle: The Doctor mentions K9's twin on Gallifrey. On Alzarius the Doctor sends K9 to track the Marshmen. In the Outlers' cave the Marshmen smash K9's head off. His head is reattached by Romana at the end of the story.

State of Decay: K9 reveals he has an aggression mode. The Doctor connects him by cables to scan the TARDIS memory-banks. He accompanies the rebels on the attack on the tower.

Warriors' Gate: K9 is damaged by the time winds - his memory wafers crumble. He is still mobile, but can only go backwards! Adric removes one ear scanner to use in tracing the void (but he is never seen to replace it!). On the other side of mirror K9 is fully repaired, but can never cross back again. The Doctor gives him to Romana. K9 has detailed plans on file of how to build a TARDIS for Romana.

K9 and Company - A Girl's Best Friend: The Mark Three model is built by the Doctor and delivered to Sarah's house in Croydon in 1978. Sarah does not open the box until 18 December 1981. This K9 appears to be made using modern components - and not future technology per the earlier models - because Brendan can identify the circuits, being a trisec bus-driver chip, a universal asynchronous receiver trans-mitter, a nucleus battery and laser-scan memory hologram. This K9 has a new handle on his top, and he can ... sing?

Castrovalva: The Doctor mentions K9 during his post-regenerative trauma.

Kinda: The Doctor mentions K9 in Part One.

The Five Doctors: K9, who is now Sarah's guard dog at her suburban house, detects danger but Sarah does not heed his warnings.


K9 is the only companion to have had any marketing potential, giving creators Baker and Martin as much copyright power as Terry Nation had over the Daleks. In this context after the Daleks, K9 became the most merchandised element from Doctor Who. The following are some of the more common collectables using K9:

Books: K9 of course features in the Target novelisations of the TV episodes, but curiously only appeared on the covers of two: The Androids of Tara and The Five Doctors. As the star of the show, he did of course appear on the jacket of Terence Dudley's novelisation of K9 and Company, published in 1987 as part of 'The Companions of Doctor Who' series (but with silver colouring rather than grey).

In 1979, Target released The Adventures of K9 and other Mechanical Creatures, edited by Terrance Dicks and illustrated by Andrew Skilleter. The book was a mixture of games and puzzles with a story guide detailing K9's TV adventures up to The Armageddon Factor. There was also an alphabetical guide to some of the robotic foes encountered by the Doctor.

In 1980, as a tie-in to the unmade animated TV spin-off series, four picture-books written by Dave Martin were published by Sparrow Books. These feature K9 as an agent of the Time Lords, who send him on secret missions in his spaceship the K-NEL. The four books are The Time Trap, The Missing Planet, The Zeta Rescue and The Beasts of Vega. K9 later appeared in Dave Martin's Make Your Own Adventure With Doctor Who: Search for the Doctor, Severn House, 1986.

A K9 Annual was published by World Distributors in 1982 and which was written along similar themes as K9 and Company. K9 and Sarah appear in six different text stories each featuring a supernatural theme. The rest of the annual consists of the usual mixture of features on space travel, UFOs, mathematical quizzes, and puzzles.

K9 has also appeared in a number of comic strips in Marvel's Doctor Who Magazine (formerly Weekly/Monthly).

K9 is due to appear in one of Virgin's The Missing Adventures novels, The Romance of Crime by Gareth Roberts.

Toys: A K9 toy was produced by Denys Fisher, and a talking model by Palitoy in the late Seventies. Dapol produced a 'pull-back action' K9 figure in 1989. This figure is wrongly coloured dark green.

Miscellaneous: There are many other items of merchandise featuring K9, including jigsaw puzzles, T-shirts, and a poster painted by Andrew Skilleter released by 'Who Dares' in 1983. The K9 and Company theme music was released as a single in early 1982.

Doctor Who Weekly/Monthly/Magazine
The Key to Time by Peter Haining
Doctor Who Special Effects by Mat Irvine

JON notes: In the 12 years between when this article was written and the 'revised' version went online, K9 has of course continued to feature in many more items of merchandise, such as further Virgin and BBC novels; short-stories; documentaries (K9 Unleashed); audios (notably Big Finish's fourteen part Gallifrey saga, and two Bill Baggs Video audio spin-offs); and an online adaptation of Shada. Of course, the biggest continuation of his story was his gallant return to TV in School Reunion, the third episode of the 2006 series, in which K9 Mark Three was destroyed but was replaced by a brand new Mark Four version. For Christmas 2006, remote-controlled K9 toys are expected to be the next big thing!

This item appeared in TSV 41 (October 1994).