This particular series has been excellent on the suspense. This is the 3rd book that I've been on the edge of my seat. Who did it? Good mystery and set-up.
On the other hand, the romance. Eh. Again. Kyle bordered on creepy and his interest in Cadence bordered (or flat out was) unhealthy. The following quote supports and explains:
"No, it was more than love. Too hard and dark and dangerous for love. Too consuming."
"She was his drug."
"His fucking everything."
I had to roll my eyes at the beginning of the book when they are in the cave and check their cells for service. Duh, you are in a cave, of course your cell phones aren't going to work! (Surprise!).