Books about teenagers who trying to solve murdering and kidnapping cases are my cup of tea. I always loved that kinda stuff. So I enjoyed this book very much. When teenagers trying to find their friend kidnaper, they have to solve many puzzles. They begin to uncover the true background of the killer and the horrors that shaped him into who he is. As Aerin struggles to play nice with the person who killed her sister in order to buy herself time, her friends work feverishly against the ticking clock that could mean her life, and every clue they uncover leads Seneca to suspect she's more connected to the killer's history than she ever realized. This book full of action and mystery. I really loved it.