Return to Telos was the eighth and final story in the fourth series of the Fourth Doctor Adventures, produced by Big Finish Productions. It was written by Nicholas Briggs and featured Tom Baker as the Fourth Doctor, Louise Jameson as Leela, John Leeson as K9 and Frazer Hines as Jamie McCrimmon.
Out of control, the TARDIS tumbles down a chasm and the Doctor and Leela find themselves caught up in full-scale planetary invasion.
As K9, controlled by an external force, drives the TARDIS away from Krelos, the Fourth Doctor informs Leela that he recognises their destination: Telos, the location of the last known Cyberman base, where a grand army lies dormant. He also guesses that what happened on Krelos has been the result of a Cyberman attack and infiltration, even if he can't explain how it happened.
Meanwhile, the Doctor realises they are travelling only in space, not in time; in fact, K9 is holding the TARDIS from entering the Vortex. The Doctor then throws himself at the console and pulls a lever, bringing the TARDIS inside the timestream continuum, and forcing K9 to set an emergency landing. As a result, the TARDIS crashes on Telos, but on a different point in time where the Cybermen intended - at the same time the Second Doctor is there with Jamie and Victoria Waterfield. K9 is also smashed to pieces by the violent impact: this allows the Doctor and Leela to dismantle him and find the Cybermat inside his brain that was controlling him. Seeing that the Cybermen were the first to interfere with their timeline has the Doctor changing his mind about going back in time, and to Krelos, to avoid the Cyberman invasion.
Back on Krelos, the Doctor and Leela reach Geralk and his associate, Relly, at the man's villa and accept their invitation to lunch. As Leela, Relly and the robot connected to Geralk's mind go into the kitchen to cook the fish it got earlier, the Doctor warns Geralk of the danger and then starts to scan the room of signs of Cybertechnology. As the robot in the kitchen puts the fish into a radar oven, this starts to malfunction: the contact with the robot has casually awakened the Cyberparasite stored inside it, and they quickly spread all around the town (which, being highly technological, is of course connected in his entirety), disrupting communication systems and alerting the Cyberfleet, whose arrival is almost immediate.
The Doctor wants to escape, but Leela opposes him, saying they have to save Krelos' people. The Doctor, persuaded, comes up with an idea, and tells Geralk to put on his robot control. As he does so, the Cybermen reach them, carrying a Cyber-conversion unit, and kill Relly; Geralk remains stuck in the machine, as the Doctor and Leela are surrounded by Cybermen.
The Doctor and Leela are saved by Geralk who, still in control of his robot, manages to snatch them and take them back to the TARDIS before being Cyber-converted in his turn. As a result, the robot stops working and begins to repeat words about the last thing he was doing when it met them: going fishing. As he watches it, the Doctor inadvertently touches the piece of tartan from Jamie's kilt he found in the TARDIS.
Then, he understands what happened. Years earlier, when he, Jamie and Victoria landed on Telos, Cyber-particles attached themselves to Jamie's clothes; when K9, tinkering with the ship, brought the control room back to an earlier configuration, those particles were activated and took control first of K9 and then of all the technology on Krelos, thus dooming the planet. Determined to prevent it from happening, the Doctor then goes back in time to Telos, carrying along in the TARDIS Geralk's robot and K9. He also recovers from Geralk's body the control unit for the robot.
Once in the TARDIS, he gets Leela to go to another room, where she could delete from her body all remains of Cyberparticles, as he prepares to use the robot. However, as he is about to do it, a shift in time starts occurring, and both the Doctor and the TARDIS begin to fade out, to Leela's fear and amazement. This happens because, in the past, a group of Cybermen sent by Cyber-Control in the future have attacked the Second Doctor, in an attempt to stop the chain of events before it begins. However, they quickly realise that, if they do eliminate the Second Doctor, the Fourth will not exist and they will not be able to take control of the TARDIS, so they desist and the timelines return to normal.
In the recovered TARDIS, the Fourth Doctor takes control of Geralk's robot and uses it to go inside the tomb, reach Jamie and take away from him all Cyber-particles, thus avoiding the console room to be infected. A restored K9, now free from Cybermen influence, accompanies it. As he is doing so, the same troop of Cybermen who attacked the Second Doctor enter the Fourth's TARDIS and try to take control of the ship. Leela fights them off and manages to resist long enough for the Fourth Doctor to complete his plan. As a consequence, time is rewritten, and the Fourth Doctor, Leela and K9 find themselves once again on Krelos, in the TARDIS, as they are about to go fishing.
Things now go smoothly: the Doctor and Leela go fishing, they meet Geralk's robot, fish with it and then stay with him and Relly for dinner. As they sleep, they take heir leave; seeing Telos up in the sky, a distant planet, the Doctor starts telling Leela about the Cybermen, wishing for her she'd never meet them.
- The Doctor - Tom Baker
- Leela - Louise Jameson
- K9 - John Leeson
- Jamie / The Second Doctor - Frazer Hines
- Geralk - Michael Cochrane
- Peter Haydon - Bernard Holley
- Relly - Veronica Roberts
- The Cybermen - Nicholas Briggs
- Cybermats are adaptable, able to have stealth capabilities or venom. One is lodged in K9's brain.
- The "TT capsule proximity alert" registers a past version of the TARDIS nearby.
- The Doctor has a device to trace Cyber-Technology moving through the computer systems of the houses of Krelos, which are all interlinked.
- Geralk says the Cybermen were "the Scourge of the Galaxy" once.
- Cyber particles are a kind of living metal.
- The Cybermen carry cyber-conversion technology, able to convert with a touch.
- This story was recorded on 7 and 8 April 2014 at Audio Sorcery.
- This story is set during the events of TV: The Tomb of the Cybermen.
- The title for this story was also a working title for TV: Attack of the Cybermen.
- This story was originally released on CD and download.
- This story forms part of a single story, beginning in The Fate of Krelos.
- The Doctor and Leela visit Telos at the time of his original visit with Jamie and Victoria Waterfield during his second incarnation in the 25th century. (TV: The Tomb of the Cybermen)
- Jamie refers to his previous encounter with the Cybermen on the Moon in 2070. (TV: The Moonbase)
- The Second Doctor refers to Eric Klieg while Peter Haydon refers to Professor Parry. (TV: The Tomb of the Cybermen)
- Leela recalls the Doctor telling her that Jamie was a warrior. (AUDIO: The Fate of Krelos)
- The Doctor and Leela return to Krelos. (AUDIO: The Fate of Krelos)
- The Doctor refers to the TARDIS swimming pool. (TV: The Invasion of Time, Journey to the Centre of the TARDIS; AUDIO: White Ghosts)
- The Doctor mentions the particulate vacuum cleaner. (AUDIO: The Fate of Krelos)
- The Second Doctor says, "Oh, my giddy aunt!" (TV: The Krotons, The Three Doctors, The Two Doctors)
- Cyber particles, called cyber-pollen, would later be used to convert dead bodies. (TV: Death in Heaven)