In 1950, three Danish farmers came across a grizzly find - a body, buried in a peat bog. It was a murder, but the police will never catch the killers. This crime took place more than 2000 years ago. The victim was named 'Tollund Man', and he is a so-called 'Bog Body' - a naturally mummified corpse buried in a peat bog during Europe's Iron Age. From Ireland to Russia, hundreds of Bog Bodies have been discovered in these soggy environments on the margins of civilisation. Thanks to the cold, acidic conditions of the bogs and a cocktail of powerful antibacterial chemicals released by plants within the bog - these bodies are incredibly well preserved. Unlike most ancient remains, Bog Bodies can retain their skin, hair, clothing and even the contents of their stomachs, preserved for millennia. They provide a unique window into the past, giving us valuable insights into life... and death... from a time and place with few written records. Many of the bodies show shocking signs of violence, but for decades there were few explanations as to why these people were so brutally killed. Now, using state-of-the-art techniques borrowed from police forensic laboratories, archaeologists are beginning to solve these ancient murder mysteries. It transpires that many Bog Bodies were not unfortunate victims of crime, nor even despised criminals. They were in fact the elite of society and their deaths were most likely human sacrifices. Their deaths were part of a highly ritualised ceremony designed to appease angry gods living in the bogs. We follow an international team of experts as they deploy the latest scientific techniques to unravel the mystery of the world's most intriguing Bog Bodies: Denmark's Tollund Man, Grauballe Man and Haraldskaer Woman. Ireland's Clonycavan Man and Oldcroghan Man and England's Lindow Man. Along the way, they will discover new insights into a crucial period of World History - the Iron Age.