In the back garden of a house in York, England, more than 45 decapitated, Roman-era skeletons are unearthed. This astonishing discovery leads to an unprecedented scientific investigation to identify the remains. Are these men pagan prisoners, savagely murdered and unceremoniously buried? Are they soldiers who were killed in battle or executed for crimes against Rome? Modern forensics, archeological sleuthing and historical records point to a surprising answer and an infamous perpetrator: the Roman emperor Caracalla. His victims speak from the grave to tell a harrowing tale of murderous sibling rivalry, bloody revenge and a deadly rampage.