Jenny Cavanaugh, a ghost girl who lives at 926 Augur Lane, makes a strange request to her neighbors—to investigate her own murder, which happened ten years ago. Eccentric detective R. F. Jackaby and his young assistant Abigail Rook dive headfirst into what seems like a hopeless case, beginning with a search for the victim’s fiancé, who disappeared on the night of her death. But when another terrifying murder occurs, almost identical to the crime from ten years earlier, Jackaby and Abigail realize that Jenny’s killer may be far more dangerous than they suspected…