The Curious Incident of the Dog in the Night-time is a novel by Mark Haddon that won the 2003 Whitbread Book of the Year, the West Australian Young Readers Book award in 2005 and the 2004 Commonwealth Writers' Prize for Best First Book. Its title is a quotation of a remark made by the fictional detective Sherlock Holmes in Sir Arthur Conan Doyle's 1894 short story "Silver Blaze".
The story is written in the first-person narrative of Christopher John Francis Boone, a 15-year-old autistic boy living in Swindon, Wiltshire. Although Christopher's condition within the autism spectrum is not stated explicitly within the novel, the summary on the book's inside cover describes it as Asperger syndrome.
The 15-year-old Christopher Boone goes to a school for students with special needs (a euphemism he disparages) because he has a form of autism. Christopher is a mathematical savant, has a photographic memory, is extremely observant and has a pathological inability to tell lies. However, he has difficulty understanding human behaviour, gestures and relationships. He takes a deep interest in mathematics. He owns a pet rat named Toby.
Christopher has many traits that separate him from others because of his perception of life. He is unable to recognise and comprehend facial expressions besides 'happy' and 'sad' and has difficulty in understanding metaphors and jokes. He likes lists and facts, has a fear of strangers and new places, and his favourite dream is one in which all "normal" people (those who are unlike him) die. In addition to that, he is over-sensitive to information and stimuli. For this reason, he screams and reacts violently to people who touch him. However, he doesn't mind pressing his fingers against those of his parents as a gesture of love. He curls up and groans to protect himself against overwhelming noise or information.
Christopher hates the colours yellow and brown, but loves red. This extends to adding red food dye to brown- or yellow-coloured food (and being unable to eat two different kinds of food that are touching), and also his belief that seeing three, four or five red cars in a row means it's a "good", "quite good", or "super good" day, respectively, while four yellow cars signify a "black" day, on which he will not eat his lunch or talk to anyone. Finally, he dislikes eating food from new places and the furniture being moved.