Phyllis Allenby is a young and beautiful woman who is soon to be married to lawyer and boyfriend Barry Lanfield. Phyllis is living at the Allenby Mansion without the protection of a male, along with her aunt Martha and her cousin Carol and the servant Hannah. As the wedding date approaches, London is shocked by a series of murders at the local park, where the victims are discovered with throats ripped out. Many of the detectives at Scotland Yard begin murmuring about werewolves, while Inspector Pierce believes the opposite and suspects strange activity at the Allenby Mansion (which is near the park), where the "Wolf-Woman" is seen prowling at night and heading for the park. Phyllis becomes extremely terrified and anxious, since he is convinced that she is the "Wolf-Woman", deeply believing