The actor explores some of the most important archaeological finds in Ireland's history, revealing how many have been used as an important tool for nation-building on both sides of the border. Speaking to world-renowned experts, he unravels a forgotten time period, when a team of Americans from Harvard University, a Nazi archaeologist from Austria, and a Welsh geography professor dug up ancient sites across the country. Their pioneering work answered questions about the Celts, and what it means to be Iris.