Two classic Doctor Who adventures, one from the 1970s and one from the 1980s, both featuring those sinister humanoids the Cybermen. In 'Revenge of the Cybermen' (1975), the Doctor (Tom Baker), Sarah Jane (Elisabeth Sladen) and Harry (Ian Marter) return to the space station Nerva (from 'The Ark in Space') to recover the TARDIS. They discover the crew decimated by a strange plague, to which Sarah falls prey. The Doctor realises that the plague is part of a plot by the Cybermen to destroy Voga, the planet of gold - gold being the only thing which is lethal to them. At the same time the Vogans are planning to destroy the Cybermen with their Skystriker rocket. The three-part adventure 'Silver Nemesis' (1988) was made to celebrate Dr Who's 25th anniversary. A statue, blasted into space 350 years ago, crashes into Earth in the core of a meteor. The Doctor (Baker) and his assistant Ace (Sophie Aldred) must fight two armies from different time periods, a regiment from 1988 and a battallion of soldiers from 2688, whilst guarding the statue from the clutches of the Cybermen.