Force of Nature kept me up way too late on a work night.  A couple of times! Only a couple of times, because I finished it so quickly... Aaron Falk returns to his day job, and I couldn't be happier. He is still dealing with the aftermath of what happened in the previous book, physically and emotionally. His guilt over his relationship with his father colors everything. Getting pulled into a missing persons case out in the middle of nowhere could have been a distraction, but Aaron's past keeps ghosting in front of him.
I enjoyed the mystery of the missing hiker, and all the ramifications the investigation into her whereabouts brings. Harper has made it to my favorite authors list.  The writing is descriptive, the terrain and location of the novel is almost another character. So different from what I am used to, which makes it even more interesting.