Summary Cristopher John Francis Boon is an autistic boy, he knows all the countries in the world with their capital and all prime numbers up to 7507. He lives with his father in Swindon. His mother died of a heartattack, well that's what his father told him... Christopher finds Mrs. Shears' dog 'Wellington' in her front garden with a garden vork sticking out of him. He strokes the dog and wonders who could have killed Wellington and for what reason. Christopher desides to investigate who killed it and writes a book about it. Christopher visits all the houses round Mrs. Shears' house which might have seen who killed Wellington. He doesn't like strangers so he doesn't go to houses if he doesn't know the owners, this includes his neighbours which play loud music all day. There is one friendly old woman who likes to talk to Christopher, Mrs. Alexander, only when she goes inside to get biscuits and tea he gets afraid and walks off. Christopher's father doesn't like him asking questions about Wellington and get's angry about it. One day he takes the book he's writing and throws it in the rubish bin. Of course Christopher wants his book back allthough he can remember most of it and write it again. The next day he looks in the rubish bin, but no book. Christopher desides to search the house for his book, his book isn't very big so he doesn't have to look in very small places. He searches the kitchen, the dining room and the livingroom. He didn't find his book so he looks upstairs but the only room he didn't check was his father's room, because he's not allowed in there. Christopher desides to search his room but not move anything so he wouldn't notice. He looks under his bed and finds 7 shoes, a combe, a chocolate bad and a magazine called Fiesta. He also finds a shoebox, he opens it and there is his book, he desides to leave the book there so his father wouldn't notice. But underneath his book he sees a letter with his name on. It says: Christopher Christopher. His father is home! He takes the letter and hides it under his matrass. When he reads it it doesn't make sence to Christopher, he's confused. But as he reads more letters he does a disturbing discovery... His mother is still alive, she didn't have a heartattack and lives with Mr. Shears in London. He feels sick and the world is turning, he throws up everywhere. He wakes up in a daze and his father keeps saying he's sorry and tries to explain he did it for his own good. Christophers father puts Christopher in bath. His father tells him HE killed Mrs. Shears' dog, Christopher thinks he is able to kill him too. That's why he desides to go to his mother in London. After a long journey he arrives at his mothers house and sees that Mr. Shears lives in the same flat. Christopher is afraid of this. His father is looking for Christopher and is afraid, he allready called in help from the police. Christopher's mother leaves Mr. Shears and goes back to Swindon with Christopher. With a project his father wins back his trust and buys a dog for Christopher. He calls it Sandy.