What could feel like a gimmick is well executed - the story begins, jumps ahead, then works backward toward the twist, day by day, in a way which kept me up way past bedtime to get to the end/beginning. The way information was revealed made sense, felt natural and yet kept the story moving and the reader on their toes. The mystery / reveal was a bit predictable, and some of the character "development" could have used refinement, which is why this gets 4 stars instead of 5, but overall it was compelling, fun to read, and I'll be on the lookout for future books from this author.