A poetic quasi-historical work set in the tenth century, depicting the death of the King of Thomond and the bravery of Brian his son. Cennidigh, King of Thomond, dies, and his son Mahon succeeds him. Another son, Brian, is granted permission and men to fight the Danes, but while valiantly fighting them, the troop suffers heavy losses. On Brian's return, he is barely recognisable, but on discovering what has happened, is greeted by his brother as a man of valour. The clan come together to follow him to arms.