“It’s a Long Way to Tipperary” is a famous war song that’s been around for more than a century now, but its reference to an obscure county in Ireland has new resonance today, because of an unexpected archaeological find there. In a remote peat bog, a worker finds a perfectly preserved human torso that becomes one of the coldest cold cases in history. Scientists date it to the Bronze Age, about 1000 BC – and historians theorize that the bodies found in that bog are those of ritually sacrificed royalty. Tonight’s Nova attempts to dig up the truth. Check local listings.