The Doctor is on his way home to Gallifrey with the remains of his arch-nemesis, The Master. Forced off course, the TARDIS arrives in San Francisco on New Year’s Eve 1999, where the Doctor is critically wounded in a gun battle. At the local hospital, Dr. Grace Holloway fights – and fails – to save his life. Later, in the morgue, the Doctor wakes up a new man. But he is not the only one – the Master has also found himself a new body. Can the Doctor stop his oldest enemy from destroying all life on Earth in time to ring in the new millennium?