Seventeen-year-old Kat Preston doesn’t believe in ghosts. If she did, that belief would give them the power to break onto our plane of existence, and after being possessed by an aggressive ghost when she was nine years old, Kat is finished with “unbelievables.” When a school project forces Kat to investigate a century-old double murder in Connecticut, she finds darker things than ghosts, and between a murderous curse and inadvertently traveling back in time to 1886 with her annoying research partner, Evan, she may become a believer yet again. By centering her supernatural world on the concept of belief, adult author Tansley (The Six Train to Wisconsin, writing as Kourtney Heintz) gives her story a complex and unusual framework, and having the formerly possessed Kat become a possessor herself, as she inhabits another woman’s body while in the past, puts a neat spin on conventional ghost story motifs. Kat’s backstory is only slightly touched upon, and her emotions and reactions can feel muted, but it’s still an intriguing and creepy start to the author’s planned Unbelievables series. Ages 12–up. (BookLife)