Christopher writes the novel because he wants to record his experience of detective. He adheres to his own rules about structure and form and only occasionally to more typical ways of writing like when Siobhan tells him to include more description in his writing. When he decides to include more description, he does so in a way that interests him, for instance when he describes the sky. Christopher breaks the mold and instinctively expresses what comes to him as he writes. I think people with special needs concentrate more in just an speciﬁc subject and that's why they appear to be stupid in other things and maybe it's just because all there attention is in an speciﬁc subject for example math.
Christopher’s condition causes him to see the world in an uncommon way and try to find logic to the world, there is the importance of mathematics and science, an essential motif, but also of thematic significance as Christopher uses these fields of study to help understand the world around him. He gives a Formula for things that are simple for us but its amazing how you can predict nature with mathematics and that is how Christopher can deal with society. He also says that with math you could resolve mysteries and he give an example giving the formula for a population of animals.