The eruption of Mount Vesuvius wreaked havoc on the Roman cities of Pompeii and Herculaneum 2,000 years ago, burying them in ash. But there's a forgotten chapter to this tragedy, involving a mass grave of 300 men, women, and children, unearthed in a Herculaneum boathouse in 1982. Found among the corpses: the mummified remains of a man, separated from the others, armed to the teeth and carrying a cache of gold and silver. Was he a hero or a villain? Scientists look for clues in the ancient city and on the body itself.