Benedict Arnold was a hero of the revolution. He was one of Washington's best generals. He had a new bride said to be the most beautiful woman in the colonies. And yet, just one month after marrying 18-year-old Peggy Shippen, Arnold reached out to the British and began to plot treason. What drove the celebrated general to betray his country? Studying never-before-seen documents, investigators are now exposing a vast conspiracy to crush America's hopes for independence with Benedict Arnold's young wife at the center.