The archaeologists learn they are stranded on Telos and Klieg suggests they use the opportunity to explore the Cybermen's tombs.

The Cybermen have been revived and plan to convert the archeologists into their own kind, prompting Hopper to attempt a rescue.

Klieg attempts to do a deal with the Cybercontroller while the Doctor tries to find a way to refreeze the Cybermen permanently.

London, 1985. The alien mercenary Lytton has been stranded here for nearly a year, but now he has a plan to escape. But how does it involve the Doctor's old enemies - and why are they on Earth at this point in history?

On Telos, the Doctor is reintroduced to the Cyber Leader and meets the Cryons, the planet's original inhabitants who will go to any lengths to get their world back!