The Doctor Falls the episode, the Doctor (Peter Capaldi) must save himself and the remaining human population of a gigantic colony ship from Mondas, while also dealing with two different incarnations of the Master (Michelle Gomez and John Simm) at once. The episode features a cameo from the First Doctor, now portrayed by David Bradley. He had previously played William Hartnell, the original First Doctor actor, in the 2013 "Doctor Who" docudrama "An Adventure in Space and Time". Aboard the colony ship reversing from the event horizon of a black hole, the Doctor finds Bill has been converted into a Cyberman. The Master
An Adventure in Space and Time with his emotional attachment to the character; with little choice, he reluctantly accepts the situation. He breaks into tears as he informs his wife Heather (Lesley Manville) of the news, admitting that he doesn't want to leave the role. Before his final scene, Hartnell shares a brief exchange with his successor, Patrick Troughton (Reece Shearsmith). As the cameras are about to record, Hartnell looks across the main console and sees Matt Smith, who will play the same role nearly 50 years later. Smith silently acknowledges Hartnell's legacy before disappearing as Hartnell begins the scene. For the thirtieth anniversary of "Doctor