Christopher Lee as Dr. Stephen Hayward

Jon Finch as Lomax

Judy Geeson as Helen

Dilys Hamlett as Julia Hayward

Tony Beckley as Sgt. Greene

Jane Merrow as Mary Dawson

Colin Jeavons as Bob Dawson

David Trevena as Johnson

Adrian Cairns as Morgan

Daphne Neville as Nurse Fisher

Hugh Smith-Marriott as Dr. Chapman

Hubert Tucker as Ronalds

David Langford as Gray