Parts: 3 (45-minute)
Writer: Russell T Davies
Airdates: 16 - 30 June 2007
Production Code: n/a

Doctor: tenth
Companions: Martha, Jack

Megalomaniac of the Week: the Master

Story: Stranded by the TARDIS and trying to cope with his sudden immortality, Jack Harkness wants nothing as much as to see the Doctor again. His opportunity finally arrives when the TARDIS lands in Cardiff for a quick refuelling stop. Racing toward the ship, Jack is only just in time to grab hold of the outside before the TARDIS disappears - but the TARDIS, instinctively reacting to Jack's unnatural inability to die, tries to shake him off by hurtling far, far into the future - to the year one hundred trillion.

The Doctor, Martha and Jack find themselves in a time period to which the TARDIS has never before travelled - so far in the future that the stars have all burned out, and humanity is desperately trying to survive the desolation of space until the universe collapses. On the planet Malcassairo, some of the last members of the human race are huddled together in a silo, sheltering from the vicious Futurekind who lurk outside the compound's walls. Among their number is the brilliant Professor Yana, who - along with the last member of the Malmooth race - is hoping to complete a rocket that will take them all to the far-off Utopia Project which, rumor has it, is attempting to develop a way for humanity to survive the collapse of the universe. But in trying to help Yana and the human refugees, the Doctor will unleash a terror that will threaten not only Malcassairo, but also present-day Earth...