The Ark in Space was a four part Doctor Who story written by Robert Holmes, and it was the second adventure to feature Tom Baker as the Fourth Doctor. The Ark in Space was originally broadcast by BBC 1 between 23 January and 15 February 1975. It was produced by Philip Hinchcliffe, and directed by Rodney Bennett. It marked the end of Barry Letts' time as the series producer.
When the late Jon Pertwee had been the Doctor he had hardly ever used the TARDIS to leave the Earth (the Time Lords had exiled him for five years, and the
The Ark in Space was the first time that the Fourth Doctor, Sarah Jane Smith, and Harry Sullivan get to go into space with the TARDIS. For a change the TARDIS does not take the Doctor and his companions to a planet, instead they land on a spacestation.
That spacestation is called Nerva, which left the doomed planet Earth many thousands of years before. On board the Nerva are the several hundred human beings that had managed to escape the Earth. These people had put themselves into an artificial stasis, which just happens to be ending when the Doctor and his companions arrive on the scene. As usual the Doctor's arrival coincides with danger or mystery.
The re-emergence of the people on board the ship from stasis should have taken place without a hitch, but it does not pan out that way. It does not take long for the Doctor to notice that something is seriously and thus dangerously wrong. On closer inspection it becomes clear that vital parts of the Nerva have been vandalised by aliens intent upon eating its passengers.
The Doctor does his best to stop the Wirm from wiping out humanity, ably assisted by Harry and Sarah Jane.
