Full review can be found here. 
 After having read several books with soppy or flowery narrators, this book was a complete breath of fresh air. Christopher does not see the world the same way as a normal person does and as a first person narrator this means that the voice of the story is very different to any other that I have read. The idea is that Christopher has decided to chronicle his investigation (with support from his class teacher) so he really is telling his own story. 
 Towards the start of the book, Christopher explains that he understands the emotions behind :) and :( but anything more complicated than that goes straight over his head and he has to rely on knowledge of what he thinks the facial expression should mean. He can't read people's emotions. He can't understand implicitations in speech (cf Grice). He does not like being touched. He has little routines that help him get through his day and he does not like it when there are factors that intervene and upset his timetable. I liked all of the little snapshots into Christopher's mind, like how he likes the colour red but he avoids anything that's yellow or brown; how he can't eat food that has touched another type of food on the plate but it doesn't matter if the different food items touched before they were on the plate. It was a very informative look into how things are for an autistic person. Considering the fact that the author has worked with autistic children, this is also a very informed look into this sort of life. The reactions of the people around him are always realistic too. I particularly liked the elderly neighbour with the dachshund. 
 There were plenty of scenes that were very emotionally powerful for me, especially the scene where Christopher is taking the underground. I felt completely overwhelmed by the situation right along with him. Another thing that I found to be very interesting was the addition of what I'm going to term 'side chapters' where Christopher would explain a moment from his life, a scientific theory or maths problem. Some of these interrupted the flow of the story, but others really added to it. In particular, I liked his ideas about the images we see in the stars and how Orion the hunter could just as easily be a T.rex - I had to stop and laugh at that bit. It is, however, obvious that the book is now a little dated as some of the scientific theories presented have now 'evolved' from the one presented by Christopher. I feel that, despite them digressing from the main plot, it was very important to include all of these passages as science and maths are Christopher's main interests so obviously he would want to talk about them in the same way that a protagonist who wants to grow up to be a professional singer and dancer would refer to singing and dancing a lot.