Christopher announces that this is a murder mystery novel. His teacher at school, Siobhan, told him to write something that he would himself like to read, and this is what he is coming up with. Siobhan has read the first page and commented that murder mysteries usually involve a person rather than a dog being killed. Christopher responds that he does not know anyone who has died and he wanted to write something that was real and true. He also likes dogs.
Two police officers arrive, a man and a woman. The policeman questions Christopher, asking him if he killed the dog. Christopher says no. The policeman continues to ask questions, much too many for Christopher to cope with. He lies face down on the ground making a groaning sound. The police officer lifts him up, but Christopher hits him.
Christopher explains that he does not understand jokes, and therefore there will be no jokes in his book.
Christopher is arrested and driven to the police station. During the drive he occupies his mind thinking about astronomy; he seems to have an excellent grasp of the science involved.
Christopher explains that the chapters of his book are numbered only with prime numbers, not cardinal numbers. He explains how cardinal numbers are calculated.
At the police station, he has to unlace his shoes and empty his pockets. He is placed in a cell while the police call his father.
Christopher explains that he finds people confusing. This is because he does not understand what facial expressions or gestures mean, and also because people talk using metaphors, rather than saying what they mean literally. He thinks that metaphors are lies because they are not literally true.
Christopher’s father arrives shortly after 1 a.m., and then Christopher is interviewed by a police inspector, with his father present. The inspector establishes that Christopher did not mean to hurt the policeman he hit. Then he asks if Christopher killed the dog. Christopher says he did not. Christopher is let off with a caution, and Father drives him home.
Christopher explains that he does not tell lies. This is not because he is a particularly good person but because he does not know how to tell a lie. If he were to try to say something happened that did not happen, he would only get confused, because he would not know how to pick one thing out of all the millions of other things that might have happened in that particular moment.
On the way home Christopher says he intends to find out who killed Wellington, but Father tells him just to forget about it. When Christopher persists, Father gets angry. They arrive home, and Christopher goes to his room, feeds his pet rat Toby, and plays computer games.
Analysis, Chapters 7-41
In a pattern that will be repeated throughout the book, the chapters alternate between the action that moves the plot forward (11, 17, 23, 31, 41, for example) and chapters that give insights into Christopher’s mind, the specific way in which he thinks and experiences the world (chapters 13, 19, 21, 37, for example). The latter are important because they establish for the reader both Christopher’s strengths (his logical approach, his ability in mathematics and his keenly scientific mind) as well as his weakness, his inability to understand other people and why they speak and act as they do. The chapters that move the plot forward show in practical terms the difficulties he has in relating to people and acting appropriately in social situations. It will also be clear to the reader by this point that Christopher is an autistic boy. The Autism Society defines autism spectrum disorder (ASD) as “a complex developmental disability; signs typically appear during early childhood and affect a person’s ability to communicate, and interact with others.” More than 3.5 million Americans live with some level of autism, from mild to severe. Christopher most likely suffers from Asperger’s syndrome, a milder form of autism, in which people may have excellent ability in their limited areas of interest, with excellent memories for facts and figures (as Christopher does).