Guest Stars Nicholas Courtney as Alistair Gordon Lethbridge-Stewart Gordon St Clair as Yeti John Lord as Yeti John Levene as Yeti Colin Warman as Yeti Jack Watling as Professor Travers Tina Parker as Anne Travers Tina Packer as Anne Travers Jack Woolgar as Staff Sergeant Arnold Derek Pollitt as Driver Evans Ralph Watson as Captain Knight Richardson Morgan as Corporal Blake Rod Beacham as Corporal Lane