River Marked was different from the other Mercy books, and I'm undecided on which version I prefer. 
 I liked that we got a lot of Mercy's background that we'd been missing. I also enjoyed the reduced angst because the relationship issues between her and Adam finally got resolved. 
 What I liked less was that beginning seemed slow, I think that's because a lot of the Native American backstory had to be fit in and that made for less action early on. We do get a good amount Mercy butt-kicking goodness, but it's left until relatively late. I also thought that Mercy and Adam as a couple deserved more screen time. 
 One big plus I will give in counterpoint is that I love how Adam is willing to let Mercy be herself. There's always the temptation with dominant characters to run over everyone in the course of getting their way, but it's nicely handled in this book. Though it's all in Mercy's PoV, we get to know a lot of what goes on in Adam's head. 
 Overall, I felt like this deviated too much from the previous books for me to be entirely thrilled with it, but at the same time I understand that Mercy has to evolve or else there's little point to continuing on with her story. Still, I love me some coyote-girl and that goes a long way.