In The Curious Incident of the Dog in the Night-Time by Mark Haddon, Christopher Boone begins the adventure of his life when he finds the neighbor's poodle, Wellington, lying dead in the yard one evening. The fifteen-year-old Christopher decides that he will investigate the "murder," and he sets off on an adventure that will eventually lead to the revelation of some incredible secrets and a major change in Christopher's life.
Christopher's father does not want his son to investigate the dog's death, especially after the mildly autistic Christopher gets in some trouble with a policeman at the beginning of the adventure. But Christopher continues and makes his first startling discovery: his father and the dog's owner (Mrs. Shears) having been having an affair. He then learns that their relationship was a response to an affair between Mr. Shears and Christopher's mother (whom Christopher thinks is dead).
Christopher soon gets caught in his investigation, and his father hides his record book. Christopher, however, is determined to continue his adventure, and as he looks for the book, he discovers another secret. He finds a bunch of letters in his father's closet, letters to Christopher from his mother, who is not dead but rather living in London with Mr. Shears. Christopher confronts his father, who breaks down and apologizes. He also admits to killing Wellington.
This terrifies his son, who sets out for London to find his mother. Adventure now becomes an even greater force in Christopher's life as he must cope with his autism on his journey. Yet he makes it safely to his mother's flat. Quite soon, Christopher's mother decides to leave Mr. Shears, and she takes her son back to their hometown. The two move into an apartment there, and Christopher reconciles with his father. He also passes his exam and begins to make plans to attend college.
Through his adventures, Christopher has recovered his family (at least to a point) and has gained confidence that will help him face future challenges.