Be warned, this dark valley is very, very dark indeed. Child murder. Extreme violence. And so on. I consider myself pretty hardy when it comes to adult themes in books, but this one had me wincing at times. But "warning to the sensitive" aside, if you're up for gruesome events then this a very good read. It's perhaps a tad long and there are a lot of typos (which doesn't bother me so much, you get the gist), yet it's gripping and well written. It has the coming-of-age theme: A group of boys on the cusp of their teenage years go out one last adventure together, where they discover buried strengths, hidden secrets, and ultimately, that their bond is stronger than they thought. While on this adventure, unbeknownst to them, a serial killer is watching their every move. The book flicks back and forth in time, so we get insights into the killer and his previous crimes, and it gets incredibly tense. If you can stomach it, I'd recommend it.