Art editor Madeleine Damian carries on numerous loveless affairs. After a failed relationship with advertiser Felix Courtland, the increasingly depressed Madeleine attempts suicide. When Jack Garet, her secretary and former lover, tries to blackmail her, Madeleine resigns and seeks a reclusive life. Neighbor David Cousins befriends Madeleine, but soon Courtland and Garet discover her whereabouts and disrupt her new life.

A young woman finds herself as the intended victim of a murder plot on a transatlantic flight from London to New York.

British Captain Terence Stevenson (Robert Donat) accepts an assignment even more dangerous than his everyday job of defusing unexploded bombs. Fluent in Romanian and German and having studied chemical engineering, he is parachuted into Romania to assume the identity of Captain Jan Tartu, a member of the fascist Iron Guard. He makes his way to Czechoslovakia to steal the formula of a new Nazi poison gas and sabotage the factory where it is being manufactured.