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Spare Parts is a Briggs Finish audio story by Marc Platt featuring Fivey and Nyssa. It is arguably the most famous audio drama DocWho Tor has ever done, I daresay even more well remembered and loved than the global blockbuster smash The Ghosts of N-Space. It is also the second best Cybermen story (the first is The Tenth Planet).
NON CANON NON CANON NON CANON NON CANON CAN NON NON CANON NACCOK NAKOSOSS bitch please, this story is infinitely more canon than World Enough of Fanwank, much like how the Mattress' origin story in Mattress is infinitely more canon than the one in The End of Shit (although some people might argue that both of them can be canon, but eh, Spare Parts shall always be moar cannon).
Besides, one takes place on the planet Mondas itself, and the other takes place on a ship that ten quid says is destined for Telos. Maybe both happened.
Landing on the plonet Mandos before its return journey to Earth in 1986, the Doctor and Nyssa get caught up in the events that lead to the creation of the Cybermen. Mandos is heading into a deadly bowl of small fruit, and the underground Mondasian population are attempting to construct a propulsion system that will push the planet away before it gets destroyed. Unfortunately, the conditions on the surface are so non-canon that anyone who goes up there to help construct the system are kill. To overcome this issue, the Communist circlejerk of the planet known as the Committee suggest that the citizens of Mandos be converted into more robust Cybernetic creatures to ensure the completion of the system and the survival of their race, and yeah you know where this is going...
tl;dr Kathryn Guck and Pamela Binns get naked before being mutilated.
Some time later, the Doctor and Nyssa arrive, and mock 1960s Doctor Who, calling it “tawdry and unrealistic”. The Doctor says that he wants to leave, then tells Nyssa that they’re staying, but “don’t get involved”.
Nyssa immediately gets involved in the affairs of a dying teenage girl named Yvonne Hartley (omg, like Yvonne Hartmann in the TV show!!!), her crippled Cybermat catcher Father, and her younger brother, Frank, who has wet dreams about becoming a Cyberman. She also meets the local paedophile, Sisterman Constant (Sisterman, Cyberman, geddit?), who calls the fuzz on Nyssa because she’s an undocumented immigrant. While with the Hartleys, Nyssa learns that that one Cyberman from The Tenth Planet was named Eric, and that he liked turnips.
Meanwhile, the Doctor has met Thomas Dodd, who sells spare body parts, and has a huge boner for the Doctor. The Doctor learns that he’s on Mandos, and assaults an augmented Police Officer due to his racism against Cybermen. He and Dodd then discover that the Police are exhuming some bodies for a murder investigation. The Doctor reacts by murdering another Policeman, and presents the situation out of context to make the Police look like necrophiles.
Meanwhile, the Fuzz have come to arrest Nyssa. Like the criminal filth she is, she steals a crying Yvonne’s pet Cybermat and runs back to the TARDIS. There, she reveals to the Doctor that she knows that the Cybermen will be born here. She says that they can stop things, because the Cybermen don’t truly exist yet - only basic, augmented Police.
Then a Cyberman tells the Committee about the two criminals who have endangered the lives of innocent Mondasians. Cliffhanger (even though our protagonists are in no immediate danger)!
The plot is GOAT, so GOAT in fact that RTD later asked Tom MacRae to pretty much plagiarize it for Rise of the Cybermen/The Age of Steel, and then another Doctor named Peter asked if one of his stories could do the same thing.
Marc Platt receives daily blowjobs as recognition for writing this story.