Ireland, 1920. Damien and Teddy are brothers. But while the latter is already the leader of a guerrilla squad fighting for the independence of his motherland, Damien, a medical graduate of University College, would rather further his training at the London hospital where he has found a place. However, shortly before his departure, he happens to witness atrocities committed by the ferocious Black and Tans and finally decides to join the resistance group led by Teddy. The two brothers fight side by side until a truce is signed. But peace is short-lived and when one faction of the freedom-fighters accepts a treaty with the British that is regarded as unfair by the other faction, a civil war ensues, pitting Irishmen against Irishmen, brothers against brothers, Teddy against Damien....