The Doctor, Tegan and Turlough attend the Master's funeral on Earth. But the Doctor is suspicious, and when the mysterious Mr Tase appears, Tegan, Turlough and a nurse called Laura find themselves pawns in a deadly game of life and death.
Returning Gravis home, the Doctor accidentally diverts the TARDIS to Queth, a planet on the verge of destruction, and the Doctor discovers he must break the first law of Time to save the doomed planet.
A trip to the Trafford Centre has diasterous consequences for a boy named Peter when he accidentally awakes a tree god called Goodma from his eternal sleep... It's a race for the Doctor to prevent Goodma's conquest of humanity.
Ever since he left Gallifrey, the Doctor has been drifting through the cosmos. But today is the day he finally discovers what kind of man he has become, today's the day he returns home... to Gallifrey.