This is one that a couple of us had already read, including me, but we decided to go for it anyway. It had been years since I read it and I thought I would just be able to skim through it, but I didn't really remember anything about it so I'm glad we read it again. The story is told by a boy who is on the autism spectrum and it starts with the murder of a neighbourhood dog and his attempt at solving this crime. He speaks very literally, and will occasionally go into minute detail about something (since his teacher tells him when writing a book, it can be a good idea to give descriptions about something, readers like that). I remember really liking this book the first time I read it, and it was true again, because it gives you an idea of how his mind works. Christoper, the narrator, likes things very orderly and predicable. He will get anxious if things are different and he isn't given the opportunity to get situated. He doesn't like to be touched. He understands what other people are like, and why they say certain things, but he isn't like they are.
I marked two passages that I really liked, one is the simple way that he talks about getting married someday and the other is about how he thinks about the smoke from when his mother was cremated being part of the rains and snow somewhere on earth. That is a comforting thought even if you don't believe in heaven.
The chapters are numbered by prime numbers, because those are his favourite kinds of numbers, and occasionally he will include a drawing or chart to illustrate what he's talking about. It's a fairly short book and a very quick read. If you haven't already read it, then pick up a copy, it's worth it.