Orson Welles directs and stars in this low-budget suspense thriller. Gregory Arkadin (Welles) is a powerful millionare who orders an investigation into his own past, as he claims he is suffering from amnesia. But as the hired investigator, Guy van Stratten (Robert Arden) digs into Arkadin's past with the help of the millionaire's beautiful daughter Raina (Paola Mori), key witnesses start suspiciously dying. The quest for information proves to be dangerous and deadly. Will Guy himself survive it?