** spoiler alert ** 
 This is a must read for any fan of the series, but it is a heartbreaking book to read because we already know what is going to happy - Courtney is going to end up dead. I read this book after having read through book 16, which made this book more heartbreaking because I knew who would be Courtney's downfall. It is also sad because you learn how real Ali has been a psychopath from a very young age and how she orchestrated Courtney's downfall. We learn how Courtney had to learn how to be like Ali in order to survive, but she lacked the cold-heartedness necessary to pull it off completely and as Ali closed in on her you can see her behavior becoming more and more erratic as she lost control. 
 The book gets a little bit confusing because of the switching of identities, by the end of the book real Courtney is literally thinking of herself as Ali and real Ali is being referred to as Courtney. It is confusing no matter how you say it and the author did the best she could, but it is still difficult to figure out who you are reading about sometimes. 
 The really sad part of this book is that no one in Rosewood will ever know the real story behind Courtney, why she acted the way she did, and that all she ever wanted was to be free. The irony is that Courtney really was better at being Ali in the end than even Ali was and that is what helps cause Ali's hatred of our little group of liars.