The Doctor and Sarah Jane return to England after their Antarctic ordeal and Chase tries to eliminate them, but they escape and track him down at his estate, where he is preparing to open the Krynoid pod.
Quest roles:
Seymour Green(Hargreaves), Ian Fairbairn(Doctor Chester), Tony Beckley(Harrison Chase), John Challis(Scorby), Kenneth Gilbert(Richard Dunbar), Michael Barrington(Sir Colin Thackeray), Sylvia Coleridge(Amelia Ducat), David Masterman(Guard Leader), Alan Chuntz(Chaffeur), Mark Jones(Arnold Keeler)