Homicide investigator Jane Rizzoli and medical examiner Maura Isles, the protagonists of a string of best-selling thrillers and a television series, have a tough case on their hands. It begins with a woman's severed hand, which is soon accompanied by the rest of the corpse, which itself may be connected to a two-decades-old mystery involving a perpetrator for whom the word inhuman may be a more appropriate description than Rizzoli and Isles care to contemplate. The novel's supernatural undertones might put off some faithful series readers, but there's no denying that the touch of otherworldliness livens up the proceedings, giving the series a much-needed energy boost. Rizzoli and Isles are likable and industrious, as always, and Gerritsen seems more engaged this time out, her prose livelier, and her dialogue more memorable. Recent series entries have been solid, workmanlike thrillers, but this one has some real spark to it. Fans should definitely check it out, and readers who have wandered away from the series might want to give it another try. Copyright 2011 Booklist Reviews.