In 1st Century A.D. Ireland, Queen Medb from Connacht has invaded Ulster, and a 17-year-old warrior, Cuchulainn, stops her army's progress single handedly. The slaughter he yields is so devastating that only one warrior remains with a chance of defeating Cuchulainn, his older brother, Ferdia. When he refuses to face his brother in single combat, Medb's daughter, Finnabair, seduces Ferdia as a component to her mother's plot, and the warrior agrees to meet Cuchulainn in the morning. Fergus, the general of Medb's army and one time friend of Cuchulainn, is distressed by Ferdia's decision. He steals away to Cuchulainn's camp and attempts to dissuade the boy from facing his brother, but Cuchulainn insists that he cannot leave his country defenseless. The following morning Ferdia rides to the ford and his meeting with Cuchulainn turns sour when the boy questions Finnabair's love for Ferdia. Their fight becomes nostalgic as the brothers remember their training in arms, but Cuchulainn's drawing first blood in the evening unravels Ferdia's sense of rivalry, jealousy, and inadequacy. On the second day these emotions emerge through their combat, and Ferdia's desire to fight outgrows Cuchulainn's when the younger brother throws down his weapons that evening. Enraged because Cuchulainn will not fight as fiercely as he is capable, and because he cannot escape his younger brother's shadow, Ferdia is more determined than ever to prove himself. The third day of their combat culminates in tragedy.