When a mysterious killer called "the Black Ace" gives his intended victims advance warning of their impending demises by leaving them the ace of spades, a mystery writer becomes determined to find the madman. But will he locate the card-carrying crazy before he lands on the demented hit list? Enthralling suspenser stars Chester Morris, Vivienne Osborne, Frank McHugh. 62 min. Standard; Soundtrack: English. Plays All Regions.