Krakauer tells the story through several different means, including excerpts from McCandless's journal, interviews, and some of his own stories. However, Penn creates a completely new viewpoint as the narrator of the movie is Chris's sister, so it is all from Chris's perspective. Krakauer compares the journey of Chris to other explorers who did similar explorations, including himself. The author includes details that would have been unbeknownst to Chris due to his death. Although Krakauer reveals to the reader the reason why there was a bus in the middle of the wilderness, Chris would have had no way of knowing the reason for the bus being there. Also, Krakauer explains the use for Chris's car after he abandoned it, but Chris had no contact with anyone regarding his car after he left