All six episodes of this story were erased in the late Sixties and never recovered. A full-length animated reconstruction, using the surviving audio, was produced in 2016. This is an important story because it begins with the first ever Doctor regeneration.
Companions Ben (Michael Craze) and Polly (Aneke Wills) enter the TARDIS as the first Doctor (William Hartnell) collapses and changes into a younger, very confused and disoriented man (Patrick Troughton). The companions are perplexed, and Ben is not entirely sure it really is the same man. The Doctor rummages through a trunk, finds a recorder, which he can play, and the 500 Year Diary, which he begins to read. The TARDIS lands on the planet Vulcan, where the Doctor sees the Examiner from Earth, who has been sent for some reason to inspect the Vulcan Colony, murdered. The Doctor takes his badge and poses as the Examiner, as a security team led by Bragen (Bernard Archard) takes the time-travellers to meet Governor Hensell (Peter Bathurst) and his Deputy Quinn (Nicholas Hawtrey). We learn that there is a rebellion going on, and that a 200-year-old capsule has been found on the planet. The travellers sneak into the lab and find two motionless Daleks covered in spider webs, and it appears a third one is missing. The scientist Lesterton (Robert James) says he took it to experiment on it, hoping to bring it back to life. The Doctor insists this is a terrible idea and strongly warns against it.
The Doctor finds a listening device in a bowl of fruit and realizes that whoever killed the real Examiner knows the Doctor is not he and is spying on them. Quinn is the one who summoned the Examiner in the first place; he is accused by Bragen of sabotage and arrested, whereupon Bragen replaces him as Security Chief. He organizes a demonstration in which the Dalek is brought to life and follows instructions. It speaks in the inimitable Dalek voice. Though it says, “I am your servant,” it still sounds like a threat. Though the Doctor continues to warn of danger, Lesterton revives the other Daleks, who obey him. Everyone in the colony seems to be fighting with each other, Polly is kidnapped, and the Daleks are multiplying. The Doctor receives a note stating that Polly will not be harmed if he does not interfere with the Daleks.
The Doctor and Ben are arrested by Bragen, who is secretly the leader of the rebels. He orders a Dalek to kill Governor Hensell, making him the new Governor, and then decides to kill the rebels too, accusing them of killing Hensell. Lesterton discovers the Daleks’ assembly line has produced an army of Daleks, and he goes quite mad with fear and grief and guilt after seeing the horrible creatures inside the robotic shells. The Daleks, who have killed rebels for the authorities and killed the police for the rebels, pretty much start to kill everyone and the bodies are piling up. By this time the new Governor is beginning to realize what a mistake he made. The Doctor, sprung from jail, creates feedback in the Daleks’ power-source, blowing them all up. Regen is shot by a rebel as he tries to kill Quinn, who ends up the new Governor. The time-travellers leave in the TARDIS as a supposedly dead Dalek on the surface moves its eyestalk to watch them.
Even in animation, the Daleks are scary, professing loyalty to humans in their creepy voices, and rolling through the corridors by the dozens. Of course, in the original, they passed in front of the camera, circled around, and passed by again, making it look as if there might be hundreds of them. With a bit of money, you can make lots of Dalek shells, but finding actors small enough to fit inside is not easy. This story was a big step forward for the Daleks, and you can see why the BBC desperately wanted it restored.