The Tom Baker Years: 1974 - 1981
The TARDIS lands on a space station orbiting the Earth in the distant future. It's seemingly deserted, but the Doctor, Sarah Jane and Harry soon discover that they are not alone. Thousands of humans - the only survivors of the human race - are in cryogenic sl--p, and while they've slept their Ark has been invaded. A parasitic insect race - the Wirm - has taken control and threatens the very future of mankind.