Glum London backdrops and washed-out color match British secret agent Charles Dobbs' (James Mason) despair at the infidelity of his nymphomaniac wife, and the possible murder of a likable and idealistic Foreign Office civil servant.
Slightly dated yet still exciting cold war spy thriller combines the talents of James Mason, Sidney Lumet, and a fine supporting cast, though John LeCarre might wonder what happened to the novel the movie is based on.
There isn't a hint of 'Swinging London'; the relationships and a gay subtext, played out on several levels, are handled maturely and without an invitation to snicker.