In the hills of Ireland’s County Tipperary, a laborer harvesting peat from a dried-up bog spots the remnants of a corpse — a headless torso almost perfectly preserved and stained dark brown by the bog. Archaeologists recognize it as one of Europe’s rare bog bodies: prehistoric corpses flung into the marshes. The corpse eventually will be dated to the Bronze Age, more than 4,000 years ago. Forensic evidence reveals a shockingly violent death. NOVA follows archaeologists and forensic experts in their hunt for clues to the identity and the circumstances of this and other violent deaths of bog body victims. A new theory emerges that they are ritually murdered kings, slain to assure the fertility of land and people. NOVA’s ancient detective story opens a tantalizing window on the beliefs of Europe’s long-vanished prehistoric peoples.