Spare Parts (Doctor Who) - Plot

Plot

A radio announcer declares that after six years training Crewman Donald Philpott will become the first human to set foot on the surface of Mondas since the inhabitants were forced to retreat underground. Once Philpott emerges, however, his heartbeat and breathing increase rapidly until, screaming, he is overcome by the vastness of the universe. Months or years later, the Doctor and Nyssa have arrived in what strongly resembles a 1950s London street, but in a huge underground cavern. They separate to explore. Nyssa encounters Mr Hartley, a Mat-catcher who traps wild Cybermats, and his daughter Yvonne. With curfew approaching, they insist on taking Nyssa home with them. Meanwhile, the Doctor finds his way into the shop of Thomas Dodd, a dealer in human body parts for transplant. Dodd confirms the Doctor’s suspicion that the planet he has landed on is indeed Mondas, and explains that the population is down to a few thousand in a single underground city. Mondas has drifted so far from any star that the surface is no longer habitable. The Doctor intends to return to the TARDIS, but Dodd tries to stop him as curfew has fallen. Outside the shop they encounter a cybernetic Policeman, a primitive cyborg, similar to but not yet as advanced as a Cyberman, who tries to arrest them for breaking curfew. The Doctor and Dodd flee. Back at the Hartley’s, Yvonne, her father and Nyssa discover Sisterman Constant, a medical official who works as a Selector, choosing candidates to become Crewmen (i.e. Cybermen) to work on the propulsion system on the surface of the planet, is visiting. Constant is highly suspicious of Nyssa, and later reports the stranger’s presence to her superiors. Elsewhere, the Doctor and Dodd are puzzled by heavy traffic movement. After climbing the tower of the abandoned Church of Former-Day Souls they discover the Police are digging up the graveyard for body parts. They are attacked by a Policeman, who the Doctor kills by pushing it into the church clock mechanism. He then sets the bell tolling, summoning the population. He hopes that, when they discover what is going on, the people will force the government to change the direction of their work, thus stopping the development of the Cybermen. At the Hartley’s a Police squad arrive in search of Nyssa. She flees, after Yvonne gives Nyssa her pet Cybermat, Matty, as a present. Meanwhile the Central Committee have decided that the Doctor and Nyssa must be found and eliminated as insurgents.