A moneylender, Stephen Hawke (Tod Slaughter), seems gentle and benign, the very essence of respectability. No one suspects his playful pastime of breaking human spines for both profit and pleasure, least of all his cherished daughter Julia (Marjorie Taylor). As his crimes multiply, terror mounts in the City of London and public outcry demands action against the fiend known as "The Spinebreaker." Stephen prudently disappears when suspicion falls on him and the police chief, Miles Archer (Gerald Barry), tries to blackmail Julia into marriage. This is enough to bring Stephen out of hiding.