The Deadly Affair is based on Call for the Dead by John le Carre. Shrewd and powerful development is given this tale of a British Home Office intelligence officer seeking to unravel the supposed suicide of a high Foreign Office diplomat.
Mason is cast as an unromantic civil servant whose official problems are further complicated by his being wed to a compulsively sexual young woman who has many affairs. His is a thorough acting job as he conducts his investigation in which he delivers one of his best performances.
Harry Andrews, as a retired CIP inspector called in to assist the intelligence officer, gives a rugged portrayal of police methods in dealing with criminals, which in this instance is a buildup to learning the identity of a foreign spy responsible for the death of the diplomat.