Regeneration was the first episode of K9, the Australian-produced spinoff series featuring K9 Mark 2. The episode first aired in the UK as a special preview on 31 October 2009. It was notable for featuring the original K9 Mark I, his ultimate destruction of, and his subsequent regeneration into his Mark 2 body. Though the Mark I model was a nod to the classic Doctor Who series, licencing issues would prove responsible for its regeneration into a different model, and henceforth, references to the classic series would be limited to avoid these issues.
In 2050 London, Starkey and Jorjie are trying to escape the police. They take refuge in a large detached house, the residence of reclusive scientist Professor Alistair Gryffen and a robot dog named K-9. After the battle with the Jixen, K-9 performs a costly sacrifice that forces him to regenerate into a brand new body, but his mind may not have weathered the process.
Two men arrive at the home and laboratory of Professor Alistair Gryffen to give him a case. The case holds technology from a "fallen angel", a downed alien craft. They tell him the Department wants a full report in twenty-four hours.
Elsewhere, a teenage boy named Starkey who operates under the pseudonym of "Stark Reality" is by an outdoor public display board terminal. He hacks in to post a dissident message. As he finishes, a teenage girl, Jorjie, arrives to yet again propose working together. Starkey refuses. When she refers to him as Starkey he is surprised she knows his real name. She says she hacked his criminal activity file. She admires his work and wants to help. CCPCs arrive and the two take off together. They end up in an alley with police at each end. They try doors until they find one unlocked.
Inside they find Gryffen's laboratory. They hide in the shadows and watch as he experiments with the space-time manipulator. When the youngsters try to leave, Starkey accidentally kicks the power plug from the wall and the machine goes haywire. Instead of the professor's lost family, four reptilian warriors come through the STM's beam. Starkey is hit with their mucus-like secretion. As Jorjie and the professor turn to aid him, a fifth being comes through the beam. It is a dog-like robot who, after distracting the aliens to allow Starkey to escape, informs the humans his power is running low and he must self destruct to destroy the four creatures. Starkey and Jorjie flee the building as Gryffen stays just outside the door, saying he suffers from a condition. Because the dog saved them, Starkey tries to help him, but is pulled back by Gryffen as an explosion rocks the room. They look inside to see the robot's parts strewn across the floor.
Starkey picks up an oval, palm-sized object that seems to be active. The surviving alien goes down the stairs. A boy arrives and asks what's going on. He notices Jorjie and introduces himself as Darius Pike, personal assistant and supplier of ordered goods, a delivery boy as Jorjie puts it. She introduces herself. Starkey warns her not to use real names so she calls him "Stark Reality". Darius comforts the distraught Gryffen and quietly places a call to the authorities while Starkey apologises to the professor. Just then the palm sized ovoid pulses and floats into the air. The parts of the robot dog are reintegrated and refashioned into a new, but still recognisable, design. The robot introduces himself as K9 and begins to recalibrate his systems, including his new flight system.
K9 exits the building for a test flight as the police arrive. They arrest Starkey, informing him of a sentence of six months in virtual reality (VR) detention. As everyone leaves the lab, the lone surviving reptile warrior, which K9 called a Jixen, sneaks off into the shadows.
Professor Gryffen works with K9. K9 informs him his memory has been scrambled and he does not recall who he is. He also says the Jixen mucus is used to mark their enemies for tracking. Any Jixen that smells Starkey will recognise him as their enemy. In response to K9's question, the Professor says the space-time manipulator was built from parts found in fallen angels, spacecraft that have landed on Earth.
Starkey is in a barren room wearing VR goggles. He sees a plain white room with no details. Jorjie appears, having used her own goggles to communicate with him. With the computer system she shows him images of aliens locked up and experimented on in a secret Department facility. He says some of them might deserve it. She tells Starkey the reason she wanted to work with him was to expose this facility to the public. Starkey points out that he is in detention and can't help her.
Gryffen works on K9 and activates a piece of music which K9 doesn't recognise; the damage to his memory is too great. He tells Gryffen he retains only fragments. He asks why the space-time travel device is here. Gryffen says the Department wants him to get it operating properly. Gryffen explains the ability to travel through space and time is enormously valuable. There is no limit to where you could go or whom you could bring. K9 asks whether he will be able to return where he came from if Gryffen fixes the device. Gryffen hopes he will. As Gryffen works on K9, the robot makes a sound. K9 explains he was in his remote identification system. Once a sound is imprinted, he can hear it across dimensions.
Soon after, an intruder alert level 5 goes off in the detention facility. They trigger the end of the VR session and Starkey turns to see the Jixen enter his cell. After he is again sprayed with the Jixen's mucus, a CCPC enters and is attacked by the Jixen. This allows Starkey to escape.
Back at Gryffen's lab, Darius is tuning up Mariah, the professor's antique car. As Darius and the Professor discuss K9 and letting him stay there, Starkey enters the lab, covered with Jixen mucus. K9's still-repairing systems identify him as a Jixen warrior. Only the professor's protestations and Starkey's repeating some of the first words he said to K9 cause K9 to stop and reconsider his actions.
As this crisis is averted, June Turner, Gryffen's primary contact with the Department, arrives to discuss the explosion in the lab and the robot "dog" seen in the vicinity. She asks if the professor has seen Starkey since his escape. June makes it clear that capturing the robot "dog" is a Department priority and she expects the Professor to find him and bring him in for study. If he fails or refuses, his funding for the STM project will be ended. It will be dismantled and given to a more co-operative researcher. Gryffen tells her there is no need to do that. After she leaves, Starkey and K9 come out of their hiding place and Starkey thanks Gryffen.
After June leaves, Starkey tells Darius that no one has ever stuck up for him like Professor Gryffen has. Darius agrees that the professor is a great guy. Starkey also thanks Darius for not turning him in. Darius tells Starkey there will be other chances. As Jorjie enters, K9 tells her about nearly "neutralising" Starkey. To apologise, K9 gives Starkey a special whistle that will call K9 wherever Starkey is.
- Gryffen's residence, an old police station with the Space-Time Manipulator in the middle is reminiscent of the Doctor's TARDIS in the form of a police box with the console in the middle.
- Channel 8 is television news.
- Before his "regeneration", the K9 seen is identical to the models originally used on Doctor Who. According to K9 creator Bob Baker, this is meant to be K9 Mark I, last seen on screen on Gallifrey with Leela. This implies that K9 Mark I survived the Last Great Time War. However, K9 Mark I was destroyed in the Big Finish Productions audio drama Gallifrey: Imperiatrix, which is set prior to the events of the Time War. If that story is to be reconciled with this one, it is possible that Romana rebuilt Leela's K9 unit against her wishes.
- The regeneration unit has writing on it which reads, in part, "δ³Σx²". In the 1972 behind-the-scenes book The Making of Doctor Who by Terrance Dicks and Malcolm Hulke, "δ³Σx²" was given as the Doctor's name. Thus, the writing on the unit would seem to indicate that the Doctor installed it in K9.
- K9 informs Professor Gryffen that much of his memory was damaged in his self destruction. K9 no longer seems to remember the Doctor. Whether he remembers his former mistress, Leela, or Romana and her K9 model, the Mark II, is yet to be seen.
- When Professor Gryffen triggers a piece of music stored in K9's memory, K9 informs the professor he cannot name the tune. The three notes played are the first three notes of the Doctor Who theme song.
- The day before this episode was broadcast, another K9 appeared in TV: The Wedding of Sarah Jane Smith.
- This episode was originally to be rebroadcast on 3 April 2010 to start the series. However for an unknown reason The Korven was broadcast instead.
- On its broadcast on the Channel 10 Network in Australia and Disney XD in the UK, June is the only character to be credited. However, on its broadcast on Five, the supporting cast is credited as well.
- Professor Gryffen's laboratory and home is in a disused police station which still bears the exterior appearance of its former purpose (police lamp next to the front door, signage, inter alia); the building is shown in The Cambridge Spy to have been an active police station as recently as 23 November 1963. This parallels the TARDIS' exterior appearance as a 1963 police box.
- The first K9 is an alternative to the K9 Mark I that first appeared in TV: The Invisible Enemy.
- Regeneration is the first of three parts, the second being Liberation and the third being The Korven.
- K-9 Mark I dies by self-destruction to kill hostile aliens and save humans in London; K-9 Mark III met his end in a similar fashion in TV: School Reunion.
Home video releases
This episode is featured in the following DVD sets:
- Series One complete box set, released in Australia on 29 September 2010.
- A "vanilla" DVD called The Bounty Hunter, containing Regeneration, Liberation, The Korven, The Bounty Hunter, Sirens of Ceres and Fear Itself, released in Australia on 29 September 2010.
- K-9: Series 1: Volume 1, containing episodes 1–12, released in the UK on 31 January 2011.
- K9: Ultimate Collectors Edition, containing the full first series, scheduled for release in the UK on 11 June 2011.