I don't know exactly what it was, but I had a blast listening to the audiobook. It's pretty predictable if you read a lot of thrillers (I do) and the "moral of the story"-type ending I really disliked (I really wanted these people to face some repercussions for their actions). But all that said - this was such a fun read, and even with all of the stuff I didn't love, I'd absolutely recommend it.