In each Gallagher book the stakes get higher and the action darker. The action is this story is non-stop. Everyone is determined to protect Cammie from the Circle of Cavan who wants her for some unknown purpose. Mr. Solomon is outed as a double agent who has been working with the Circle since he was a boy. Cammie, Macey, Bex, and Liz can't believe that could be true but all the adults are telling them that it is. That sort of betrayal is especially hard for Cammie to accept because he was her father's best friend. She is determined to find out the truth about him no matter what it will take.The mysterious Zach makes another appearance and some of the mystery about him is revealed. I liked the relationship between Zach and Cammie. I really like the relationship between Cammie, Bex, Macey and Liz. Each of them has strengths and foibles too. Cammie's voice is perfect for this story and I love her PRO and CON lists which range from teenage trivial to life-altering. Fans of the Gallagher girls won't want to miss this one and will be eager for the next.