A Greek general takes leave from the 1912 Balkan War to visit a small island in Greece, where his wife is buried. A plague soon breaks out and he is forced to stay when quarantine is declared.
The film's script was inspired by the painting Isle of the Dead by Arnold Böcklin, which appears behind the title credits, though the film was originally titled Camilla during production. It was written by frequent Lewton collaborator Ardel Wray. It starred Boris Karloff. Isle of the Dead was the second of three films Lewton made with Karloff, and the fourth of five pictures Robson directed for Lewton.