Book excerpt: When Nathan Davis dies in a car crash, his sister is left in pieces. In honor of her brother she decides to tell his story, starting way back in 1963. But it doesn't take long for her to realize that there is more than one beginning to the story. Inspired by the butterfly effect, she uncovers just how many factors it took to ultimately cause the accident that killed her brother. "The butterfly that killed Nathan Davis" is a story of how everything that happens to us is a construct of the thousands of years that have come before. And it's not the large events, but small details that have changed the trajectory of history to lead us to this exact day.