One to be read only if (a) you've nothing much else to read and (b) someone else paid for it and left it on a train....
Amazing research work perhaps, but the story fails on so many levels as soon as you start thinking about it (I know, that's always a dangerous thing to do with authors who churn out so many books in such a short period, but I just can't help it).
Someone else here mentioned the repetitive nature of the chase through the forest - and another person commented on the weird ability of the protagonists to see accurate detail over long distances through thick forest in the dead of night. I found myself wondering if the remaining 200 or so pages would be more of the same....
Sadly, they weren't as the book got worse once all the plot twists and extraneous character details suddenly kicked in. I'm not going to spoil the ending as I don't want a scolding from the Goodreads spoiler police, but let's just say that Deaver must have lots of very gullible readers if this was a best seller. I felt cheated by the ending as it was just so literally "out of character" compared with what had gone on before. The same is true of the twists and turns in the plot. We are expected to believe that people would not, even through hours of hiking, hardship and the obligatory "sharing", discuss the event that completely unexpectedly got them into their predicament. Thriller & detective novel writers love coincidences but this one takes it to the point of absurdity.
As for the characters and their hang-ups, motivations, fears etc. - well, we're talking psych 101 soap opera stuff here. However, for all you soap addicts, the happy ending for all the good guys, however tortured, confused or misguided, is reassuringly (if unbelievably) safe and sound.