The TARDIS arrives on Earth in a new ice age. The travellers make their way into a base where scientists, commanded by Leader Clent, are using an ioniser device to combat the advance of a glacier.
Patrick Troughton
as The Doctor
Frazer Hines
as Jamie McCrimmon
Deborah Watling
as Victoria Waterfield
Peter Barkworth
as Clent
Peter Sallis
as Penley
Wendy Gifford
as Miss Garrett
Angus Lennie
as Storr
Peter Diamond
as Davis
George Waring
as Arden
Malcolm Taylor
as Walters
Roy Skelton
as Voice of the Computer
Bernard Bresslaw
as Varga
