Overview: There has been a series of mysterious vanishings on the desert planet Chronos in the 33rd century. Survey teams working for a university seem to have simply vanished amongst the pyramids on the planet. Alongside two other survey teams and an expert on cybernetics, the Doctor and Evelyn learn the deadly truth: that the planet Chronos is being used as a base for one of the Doctor's oldest and deadliest foes — the Cybermen.
Overview: The planet is under Cyber control. Why do they want the TARDIS? The Controller's plan becomes clearer.
Overview: Isherwood has a proposition; Goddard has a plan. Remembering an old song...
Overview: "Friendship is your downfall, Doctor." Playing God with time as your toy. The Controller's influence is strong.
Overview: Hiding among Cybermen. Morality is a luxury. A bit of sabotage.
Overview: The temporal wave hits. Considering the future. The historic flight.