Arriving on Space Station Nerva in its distant past, the Doctor, Sarah and Harry find its crew threatened by a mysterious plague. Discovering that things are not as they seem, they uncover a Cyberman plot to destroy Voga, planet of gold.

Tom Baker
as Doctor Who

Elisabeth Sladen
as Sarah Jane Smith

Ian Marter
as Harry Sullivan

Ronald Leigh-Hunt
as Commander Stevenson

William Marlowe
as Lester

Kevin Stoney
as Tyrum

David Collings
as Vorus

Alec Wallis
as Warner

Michael Wisher
as Magrik

Christopher Robbie
as Cyber-Leader
CinemaSerf
The "Cybermen" were never my favourite enemy of the "Doctor" - they were OK in the monochrome days with William Hartnell but I didn't really rate them later on. Anyway, this time we see Tom Baker, "Sarah Jane" (Elisabeth Sladen) and "Harry" (Ian Marter) back on the "Nerva Beacon" only discover that ...