Christopher John Francis Boone knows all the countries of the world and their capitals and every prime number up to 7,057. He relates well to animals but has no understanding of human emotions. He cannot stand to be touched. Although gifted with a superbly logical brain, Christopher is autistic. Everyday interactions and admonishments have little meaning for him. Routine, order, and predictability shelter him from the messy wider world. Then, at fifteen, Christopher’s carefully constructed world falls apart when he finds his neighbor’s dog, Wellington, impaled on a garden fork, and he is initially blamed for the killing. Christopher decides that he will track down the real killer and turns to his favorite fictional character, the impeccably logical Sherlock Holmes, for inspiration. But the investigation leads him down some unexpected paths and ultimately brings him face to face with the dissolution of his parents’ marriage. As he tries to deal with the crisis within his own family, we are drawn into the workings of Christopher’s mind.