The Ulstermen eventually rouse, one by one at first, and finally "en masse". The final battle begins. Cú Chulainn stays on the sidelines, recuperating from his wounds, until he sees Fergus advancing. He enters the fray and confronts Fergus, who keeps his side of the bargain and yields to him, pulling his forces off the field. Connacht's other allies panic and Medb is forced to retreat. At this inopportune moment she gets her period, and although Fergus forms a guard around her, Cú Chulainn breaks through as she is dealing with it and has her at his mercy. However, he spares her because he does not think it right to kill women, and guards her retreat back to Connacht as far as Athlone.