Another adventure for the intrepid space/time traveller. The Doctor (Tom Baker) has returned the TARDIS to his home planet of Gallifrey, but why has he forbidden Leela (Louise Jameson) to accompany him? Why, upon claiming the Presidency, does he expel every senior Time Lord to the outer wastes? And what plan is he hatching with the hostile Vardans? The only people he seems to have taken into his confidence are K9 and Chancellor Borusa, but whatever game the Doctor is playing, he has reckoned without the return of an old foe... This story marks the departure from the series of Leela and K9 Mark 1.

All four classic Doctor Who stories featuring the alien species, the Sontarans, who first appeared in the 1973 story, 'The Time Warrior'. The Sontarans are a self -cloning race who live in a militaristic society in the 'southern spiral arm of the galaxy'. Humanoid in appearance, with a squat build and distinctive dome-shaped heads, they are far stronger than mere humans and possess an unquenchable thirst for war. The other stories in this set are 'The Invasion of Time' (1977), 'The Two Doctors' (1984) and 'The Sontaran Experiment' (1975).