During World War II, Willowjean "Will" Parker is a circus runaway whose knife-throwing skills saved the life of New York's most unorthodox private investigator, Lillian Pentecost. Now they're crime-fighting partners, trying to understand why Abigail Collins was found bludgeoned to death with a crystal ball following a big, boozy Halloween party at her home—her body slumped in the same chair where her steel magnate husband had shot himself. Some people think his ghost came back to kill Abigail, but Will and Lillian risk their own necks to find a killer who is still very much among the living.