Mysterious forces are at work in 1930s Tibet. The once gentle Yeti have turned savage and besieged a Buddhist monastery. The Second Doctor, Jamie and Victoria arrive expecting a friendly welcome from the abbot, but soon become ensnared in the plans of the extradimensional being known as the Great Intelligence.

Patrick Troughton
as The Doctor

Frazer Hines
as Jamie McCrimmon

Deborah Watling
as Victoria Waterfield

Jack Watling
as Professor Travers

Wolfe Morris
as Padmasambhava

Charles Morgan
as Songsten

Norman Jones
as Khrisong

David Grey
as Rinchen

David Spenser
as Thonmi

Raymond Llewellyn
as Sapan