The Curious Incident of the Dog in the Night-Time tells the story of Christopher Boone’s investigation that leads him to uncover a variety of family secrets and eventually struggle against the personal, developmental limitations on his independence. In the novel’s opening scene, Christopher finds the body of Mrs. Shears’ poodle, Wellington, with a garden fork stuck through its body. This gruesome discovery becomes the plot’s inciting incident, as Christopher makes it his mission to discover who murdered Wellington. Christopher’s father staunchly opposes his investigation, insisting that Christopher stay out of other people’s business. At first, this command seems like natural, parental advice, as Christopher lacks the social skills necessary to navigate difficult situations, especially with people who are not aware of his special needs. When the police officer grabs Christopher, for example, Christopher strikes the officer and spends a few hours in jail. The officer lets him off with a warning, but a similar episode in the future could have more devastating consequences. Other adults in Christopher’s life, such as his teacher Siobhan, seem to agree that Christopher should refrain from investigating Wellington’s murder.
Against the advice of his father, Christopher continues with the investigation because he is deeply concerned with the truth, a fixation that is not so much moral as it is an intense need for structure and security. Facts that are verifiably true, like mathematical proofs, are a comfort to Christopher. Things that are untrue or more nebulous in meaning—like imagination, metaphors, and interpersonal relationships—distress Christopher to the point of debilitation. Christopher’s motivations are at dramatic odds with his father’s, as his father has been lying to Christopher for a very long time. Not only did Christopher’s father kill Wellington, but he also told Christopher that his mother is dead, when she has really been living in London with Mr. Shears the last two years. Christopher’s father is naturally terrified that his highly intelligent son will uncover the long chain of deception that led to murdering Wellington. When his father discovers Christopher’s book, finding that Christopher was growing closer to the truth, his father becomes unhinged, throws the book in the garbage, curses at Christopher, and strikes him.
Christopher’s relentless, obsessive nature and the extent of his father’s deceit come to a head when Christopher searches for the book in his father’s room, and finds it hidden in a box that also contains recent letters from his mother. Reading these letters, Christopher discovers that she left their family because she believed she was not a good mother, and she lives in London with Mr. Shears. The information is too much for Christopher to process, and he vomits all over himself and passes out in the middle of his father’s bedroom. When his father discovers Christopher with the letters and realizes that he can no longer hide the truth from his son, he confesses to killing Wellington, and apologizes for all the years of deception. However, because truth, structure, and rules are so important to Christopher, their relationship is irreparably altered. Believing he is in danger with his father, Christopher decides he has no choice but to go live with his mother in London, and leaves to find her.
This search turns into a harrowing journey for Christopher, who is terrified of strangers and finds unknown places overwhelming. After many hours of wrong turns, turbulent interactions with strangers, and overwhelming sights and sounds, the climax of the novel occurs when Christopher overcomes his personal limitations and arrives at his mother and Mr. Shears’ flat. His arrival upsets both parties, as Mr. Shears has no patience for Christopher’s needs, and his mother had no idea that Christopher thought she was dead. Soon after, Christopher and his mother return to live in Swindon, and Christopher completes his A-level mathematics exam, a goal he relentlessly fixated upon, despite the inconvenience the exam caused his mother. Emboldened by the success of his investigation, his courageous solo trip to London, and his exemplary grade on the exam, Christopher feels confident about his future and his capacity for more independence. Although Christopher’s version of the conclusion is uplifting, the wide gap between his intellectual and emotional capacities and his demonstrated inability to accurately interpret situations leave the reader feeling uncertain about Christopher’s new life in Swindon with two impulsive parents who despise each other.