New York in the 1940s. Lillian Penticost is the city’s most famous private detective, but her health is starting to fail. After meeting Miss Parker, she decides to hire the girl as an assistant—after all, Willoughdin has a unique set of skills: expertly throwing knives, opening any lock blindfolded, and easily taking down men who are twice her size. Soon, this extraordinary duo has to investigate a mysterious murder. At the Collins mansion—at a Halloween party—an infamous fortune-teller is invited. During the séance, the host, Abigail, is found dead. The study is locked from the inside, with no visible clues. And the only hint is a bloodstained crystal ball…