What clues do we get from the inspiration written on the flyleaf that a mystery surrounds the relationship between the brothers?

This novel is constructed into very short chapters, each with a straightforward title giving the reader a sense of where the narrator is going or what he will do next. The events of the chapter are thus not entirely surprising. This manner of expressing a key to the enigmatic is representative of the book as a whole on many levels. Kidnapped could be described as one of Stevenson's fictions of adventure. Though critics have often separated the novel from Stevenson's Treasure Island, the two do share a somewhat parallel theme of a boy going through a rite of passage into adulthood. After his father passes away, the protagonist strikes out on his own into the world at large. A loss of innocence theme results because of the growth from youth to manhood, a path to maturity through obstacles which will have to be overcome.