This was a great book! I love the mashup of police procedural and the supernatural. The book is a retelling of the Pied Piper with an exceptionally sinister bent. The collision of modern-day Chicago and ancient fairy tale was very well done. I must admit I could see what was up quite early, but that didn't affect my enjoyment of the book. Instead, it contributed to the buildup of dread. 4.25 stars