In the rolling hills of Ireland's County Tipperary, a laborer harvesting peat from a dried-up bog spots the remnants of a corpse and stops his machine just in time, revealing a headless torso almost perfectly preserved and stained dark brown by the bog. Archeologists recognize the corpse as one of Europe's rare bog bodies. They hunt for clues to the identity and violent death circumstances of victims unearthed in Ireland's bogs and reveal the strange beliefs of the long-vanished peoples of Europe - the Celts.