Earth 1983. The mysterious Black Guardian hovers over the shoulder of English public schoolboy, Turlough, determined to enlist his aid in his deadly scheme – the assassination of the Doctor. Meanwhile the TARDIS is trapped inside a huge space ship in perpetual orbit, a permanent resting place for the miserable Mawdryn and his 8 fellow scientists, all condemned to a state of perpetual regeneration. Only The Doctor’s life force can free them, but at a deadly cost – the price of his powers of regeneration.
With Nyssa and Tegan stranded in the time zone of 1977, and the Black Guardian closing in, The Doctor must face a terrible dilemma…
Originally transmitted 1 – 9 February 1983, this four part adventure starring Peter Davison is the first in the Black Guardian trilogy and sees the return of a familiar face – Brigadier Lethbridge-Stewart (Nicholas Courtney) – and the introduction of a new one – Turlough (Mark Strickson) who went on to become The Doctor’s new assistant.