Episode One moves through the natural cycles of the seasons, witnessing spectacular scenes from the natural world, discovering Celtic rainforests and exploring complex subjects, like the formations of the rocks and underground caverns and mysterious disappearing lakes on the Burren. We discover what Ireland might have looked like when the first nomadic big-game hunters came here. We follow the three distinct populations that lived in Ireland in prehistoric times and unravel the secrets of this unique and mysterious landscape and those who lived on it.