Watch Secrets Season 4 Episode 7 Online

In Northern Europe, many ancient bog bodies have been discovered, spread across hundreds of square miles of cold wetlands. These corpses tell a story of brutal death and mysterious rituals during Northern Europe's Iron Age. For decades, there were few explanations as to why these people were so violently killed. Now, using new techniques utilized by police to solve modern murders, archaeologists are cracking these 2,300-year-old cold cases, while discovering new insights into this enigmatic period of world history.