 When the naval construction designer Oliver Reed (Kent Smith) meets the Serbian Irena Dubrovna Reed (Simone Simon) in the zoo, he flirts with her and they sooner fall in love and marry each other. However, Irena is afraid of an ancient course of her town that women can not be touched by a man, otherwise she will transform in a panther, and the couple does not consummate their marriage. Irena is sent for treatment with the psychiatrist Dr. Louis Judd (Tom Conway), while Oliver looks for "consolation" with his colleague Alice Moore (Jane Randolph). When Irena sees that she is losing Oliver to Alice, she becomes jealous and hateful, leading to a tragic end.