Christopher John Francis Boone knows all the countries of the world and their capitals and every prime number up to 7,057. Although gifted with a superbly logical brain, Christopher is autistic. Everyday interactions and admonishments have little meaning for him. At fifteen, Christopher's carefully constructed world falls apart when he finds his neighbour'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 favourite 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 Christopher tries to deal with the crisis within his own family, the narrative draws readers into the workings of Christopher's mind.

And herein lies the key to the brilliance of Mark Haddon's choice of narrator: The most wrenching of emotional moments are chronicled by a boy who cannot fathom emotions. The effect is dazzling, making for one of the freshest debut in years: a comedy, a tearjerker, a mystery story, a novel of exceptional literary merit that is great fun to read.