Set in late nineteenth century Paris, the film follows the efforts of Charles Dexter Ward, a young American student, to make the acquaintance of an ageing musician who lives a secluded life in the room above him at a boarding house. Ward is fascinated, then driven to unravel the mysterious circumstances surrounding Zann and his music: he wants to learn why Zann plays wondrous, often awesomely compelling music late at night. Based on a short story by H.P. Lovecraft.