Captain Jack Harkness
reunites with the Doctor and the TARDIS
is thrown out of control to the end of the universe. They meet
Professor Yana, who is working on a means to save the remnants of
humanity while a race known as the "Futurekind" attempt to thwart his
- This is Derek Jacobi's third involvement in Doctor Who and second time playing the Doctor's nemesis. The first was in the September 2003 audio drama Deadline, where he played a screenwriter who believes himself to be the Doctor. The second was several months later, in the webcast Scream of the Shalka, where he played an android version of the Master. David Tennant also had a minor, uncredited role in Scream of the Shalka.
- John Bell is a nine-year-old who won a Blue Peter competition to appear in this episode.