I don't know what it is but I just love a book with a fancy school and an un-alived person mystery to solve!

After a party in the woods on Halloween ends in tragedy, Ellie's involvement comes into question as she lied of her whereabouts to her parents. Rachel is the school councilor and Ben is a detective. 

What I thought was unique about this was that the two MCs are divorced and on both sides of the investigation so it gives a perspective that gives a lot of insight. There are some twists that threw me and my suspicions were way off base! But the outcome was a bit chilling as to how cruel a person could actually be.