Patrick Troughton stars as the Doctor in this 1967 TV serial set on the Moon. In 2070 the Doctor and his travelling companions Jamie (Frazer Hines), Polly (Anneke Wills) and Ben (Michael Craze) arrive on the Moon and set out to visit the Moonbase, a manned structure used to control the Earth's weather through a device known as the Gravitron. All is not well on the Moonbase, however, with many of its crew suffering from a mysterious virus. It isn't long before the base is quarantined, leaving the Doctor, Jamie, Polly and Ben to try to get to the bottom of events and to deal with the increasing threat posed by the Cybermen, who appear to have infiltrated the base. With two of the original episodes missing, animated reconstructions are used to complete the story.