The detective known only as The Continental Op investigates a theft of diamonds from the Leggett family of San Francisco. The plot involves a supposed curse on the Dain family, said to inflict sudden and violent deaths upon those in their vicinity. Edgar Leggett's wife is a Dain, as is his daughter Gabrielle Leggett. The detective untangles a web of robberies, lies and murder. It is discovered that Gabrielle Leggett is also involved in a mysterious religious cult and is addicted to drugs.