Doctor Who, Ark in Space: Movie Version

S12 E101: The TARDIS lands on a space station orbiting the earth in the distant future. It's seemingly deserted, but the Doctor, Sarah and Harry soon discover that they are not alone. Thousands of humans - the only survivors of the human race - are in cryogenic sleep. But while they have slept, their Ark has been invaded. A parasitic insect race - the Wirrn - have taken control and threaten the very future of mankind.