In Gary Paulsen's novel Hatchet, "the secret" is hinted at from the beginning of the book. From the first page, readers know that Brian's parents are getting a divorce and that there have been lots of secrets, including "the secret." But it isn't until Chapter Four that readers learn the details of this secret. Chapter Three details the plane crash that stranded Brian in the Minnesota wilderness. Chapter Four opens with Brian's memories of "the secret." Brian is in the plane as it is crashing and has pieces of the memory flash through his mind. Flashes of "the secret" are that he was at the mall with his friend Terry and saw his mom sitting in a strange vehicle with a man Brian didn't know.
Terry had first turned to smile at him about something and Brian looked over Terry's head and saw her. His mother. She was sitting in a station wagon, a strange wagon. He saw her and she did not see him. Brian was going to wave or call out, but something stopped him. There was a man in the car. Short blond hair, the man had. Wearing some kind of white pullover tennis shirt. Brian saw this and more, saw the Secret and saw more later, but the memory came in pieces, came in scenes like this—Terry smiling, Brian looking over his head to see the station wagon and his mother sitting with the man, the time and temperature clock, the front wheel of his bike, the short blond hair of the man, the white shirt of the man, the hot-hate slices of the memory were exact. The Secret. Brian opened his eyes and screamed.
This is all that readers learn in Chapter Three and Four about "the secret." Readers learn that this memory fills Brian with hate, that he remembers this experience in vivid detail, including what the clock and the temperature were at the time. We can infer this caused the divorce, but nothing else is said about the secret at this point in the novel.