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
The Doctor
Frazer Hines
Jamie McCrimmon
Deborah Watling
Victoria Waterfield
Peter Barkworth
Clent
Peter Sallis
Penley
Wendy Gifford
Miss Garrett
Angus Lennie
Storr
Peter Diamond
Davis
