If you want to have an idea of what is going on in this, make sure you've read from #3 and on in this series, this is #6. I read #3 in 2014 and #5 in 2016 and I could barely hang in there as it was in the beginning.
This pretty much follows the mystery set up in the books I mentioned, one of the bigger villains is pretty much already dealt with but while the other books dispatched of him, they also hinted at someone else behind the scenes, this is all about the hunt for that someone behind the scenes.
I feel like I've been complaining about this a lot lately, just my string of luck with picking stories I guess, but our hero and heroine had a childhood friendship, we get no scenes of it. Basically, she already has found him sexy and wanted him, while he is waking up to the fact that he, too, has always wanted her. I missed watching and experiencing the development of attraction.