Tom Baker assumed the role of the Doctor’s fourth incarnation in the series’s 12th season (after a brief appearance in season 11). Fresh from his latest regeneration, the Doctor, Sarah Jane Smith (Elisabeth Sladen), and new companion Harry Sullivan (Ian Marter) must defeat a giant mechanical menace, in "Robot." "The Ark in Space" finds the Time Lord and his friends in the distant future, where the last survivors of Earth are threatened by insect-like aliens who take control of human hosts. Next, the Doctor and his companions help would-be settlers of an abandoned future Earth overcome the menace of "The Sontaran Experiment." The Doctor is sent to the war-ravaged planet Skaro's distant past in an attempt to alter history and disrupt the "Genesis of the Daleks." And, the Doctor, Sarah Jane, and Harry travel to the far future, where they try to free a manned space station from tyranny, in "Revenge of the Cybermen."

20 episodes on 6 discs. 8 2/3 hrs. Standard; Soundtrack: English Dolby Digital 5.1; interviews; more.