In postwar Vienna, Austria, Holly Martins, a writer of pulp Westerns, arrives penniless as a guest of his childhood chum Harry Lime, only to learn he has died. Martins develops a conspiracy theory after learning of a "third man" present at the time of Harry's death, running into interference from British officer Major Calloway, and falling head-over-heels for Harry's grief-stricken lover, Anna.
A team of allied saboteurs are assigned an impossible mission: infiltrate an impregnable Nazi-held island and destroy the two enormous long-range field guns that prevent the rescue of 2,000 trapped British soldiers.
Phillipe, the son of an ambassador in London, idolizes Baines, his father's butler, a kind of hero in the eyes of the child, whose perception changes when he accidentally discovers the secret that Baines keeps and witnesses the consequences that adults' lies can cause.
