The reason I keep reading book in a series which I don't love is that I find these books really easy to read, especially since I have a little bub at home and an addled brain since having said bub. 
 I like the story world, but the story has little depth. Similarly, none of the characters have much depth- they are personality traits rather than personalities. It is a book that seems to be written with a lot of head and not enough heart- it may have been three stars but then when characters lives were in peril there seemed nothing at stake and I didn't really give a rats. It's obvious nothing is going to happen to them and I found I wouldn't have cared if it did.