The Doctor and Donna land in a frightening position in the far future. While investigating a derelict library, the duo come face to face with the disembodied mind of a little girl, an archaeological team led by a woman from the Doctor's future, and swarms of flesh-eating creatures that are seen only as shadows.

As the Doctor makes his final journey to the shores of Lake Silencio in Utah, he knows only one thing can keep the universe safe – his own death – in the concluding episode of this series of the time-travelling drama. But has he reckoned without the love of a good woman?