Air: Feb 1 1983. 4 eps.
The first chapter of The Black Guardian Trilogy. A young man named Turlough is suddenly contacted by The Black Guardian who offers him to return to his home planet in exchange for assassinating The Doctor. The Doctor meets him and together they discover a hidden spaceship full of scientists who are suffering from perpetual regeneration. Their leader Mawdryn has a plan on stealing The Doctor’s remaining lives and giving them to themselves. Can The Doctor stop them before he’s out of lives himself?