I've read several of Tess Gerritsen's novels, but I've never been able to get into her Rizzoli and Isles books. I'm a sucker for a survival story, though, and was intrigued enough by the description on the flyleaf to give it a try. It did not disappoint in that area. Maura's struggle to live through the punishing cold early in the book and, later, eluding would-be killers with the boy Rat were both compelling to me. 
 I also found myself connecting with Maura on a deeper level than my previous experiences. She begins the book at an impasse with her current lover (Isles seems to have a bad track record in choosing lovers). Her impulse to do something, anything to break out of her life's pattern is very understandable and, naturally, leads to trouble. Her experiences help her clarify what she wants to do with the relationship - mostly by blasting her out of her love-angst. 
 I don't want to give any spoilers, but the book starts with a 'garden variety' polygamous cult with a charismatic prophet. You think you know what happened to his followers... but you don't. You also think that the boys raised in this patriarchal cult would be greatly valued and groomed to rule... but they're not. The ending holds a final twist that truly did surprise me... but made sense at the same time. 
 This was a great read. I plowed through it within 24 hours - it was that enjoyable. I think other non-Rizzoli and Isles readers might enjoy it, too.