I loved this. The story is great, the characters are charming, and I could listen to the narrator all day long.
I came across this book because I have read all of the Bartimaeus books by Mr Stroud and enjoyed those, and Goodreads sent me an email telling me about "new releases by authors I've read", including this one.
I liked this even better than the Bartimaeus books because it seems more universally appealing. As with those, there's still some magic involved here, but it's fairly subtle, and you get more of the "human side" of things. Plus, it's a mystery with enough plot twists that you spend good time on the edge of your seat.
This is likely intended for a young-ish audience as the protagonists are teenagers. Yet, I'm a 37-year-old whose children are far too young for books of this ilk, and I absolutely loved it. To enjoy it, you don't have to believe in magic, but you do need to like hearing stories in which the characters display some degree of supernatural power.
The narrator makes it incredibly enjoyable to listen to, capably bringing the characters to life.
Mr Stroud, please hurry up and write another; and Ms Raison, please insist upon narrating it.