A British scientist is discovered to have been passing information to the Communists, then kills himself. Another scientist decides that they might have brainwashed him by a sensory deprivation technique, but he doesn’t know if someone really can be convinced to act against their strongest feelings. So he agrees to be the subject in an experiment in which others will try to make him stop loving his wife.
Dirk Bogarde
as Dr. Henry Laidlaw Longman
Mary Ure
as Oonagh Longman
John Clements
as Major Hall
Michael Bryant
as Dr. Danny Tate
Wendy Craig
as Annabella
Harold Goldblatt
as Professor Sharpey
Geoffrey Keen
as Calder
Terry Palmer
as Norman
Norman Bird
as Aubrey
Terence Alexander
as Rowing Coach (uncredited)
Grace Arnold
as Train Passenger (uncredited)
Timothy Beaton
as Paul Longman (uncredited)
