An out-of-work American writer, Holly Martins, arrives in post-war Vienna that has been divided into sectors by the victorious allies, and where a shortage of supplies has led to a flourishing black market. He has come to join his old friend Harry Lime, who has offered him a job. On arrival he discovers that Lime has recently dies in a traffic accident. In talking to Lime's friends and associates, Martins notices that their stories are inconsistent, and sets out to discover what really happened to Harry Lime.