This is the third book in the Diary of a Serial Killer series. Make sure you read Just Things and Jimmies Ice Cream before you read Thing Fifteen. I was really looking forward to reading this and I wasn't disappointed. Ended up reading it in one sitting. 

Thing Fifteen is the story of Beverly Watkins who was kidnapped and killed by Jimmie the Ice Cream Man. He kept her in a freezer and took her out sometimes to spend time with her. She now wants her revenge on Jimmie. 

This is a super read. I absolutely loved reading Beverlys story. Looking forward to reading more from this author.