Overview: From Ireland to Denmark, dozens of 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 for why these people were so violently killed. Now, utilizing state-of-the-art techniques used by police to solve modern murders, archaeologists are starting to crack these 2,000-year-old cold cases, while discovering new insights into this enigmatic period of world history.