Thing Fifteen is a literal and figurative haunting addition to the Diary of Serial Killer series. This one is more about Beverly, or Jimmie's Thing Fifteen, but we also get more answers about Jimmie's upbringing and the things that started it all. The story makes for a good nature vs nurture discussion, at once again, the author has done such a good job of letting the reader inside Jimmie's mind that I found myself feeling a bit sorry for him. Of course, that sympathy doesn't last long when we're reminded of the things he's done and the reason for his current situation. Beverly's story is an interesting idea of the possibility that it's never too late for a bit of retribution and even a little justice. Everything isn't quite tied up in a neat little bow, but considering the subject matter, I wouldn't expect it to be. All in all, a solid addition to the series.