On November 24, 1971, a man boarded a passenger plane in Portland, Oregon. Later, he would become known as D. B. Cooper. But that wasn't his real name, and he was no ordinary passenger. He hijacked the plane, demanded $200,000, and parachuted out of the plane with the money. He was never seen again. Who was D. B. Cooper, and what happened to him? Explore the theories behind this crime and why it has become one of history's greatest mysteries.