In the early 20th century, Michael Collins (Liam Neeson) leads the Irish Republican Army with the help of his friends Harry Boland (Aidan Quinn) and Eamon de Valera (Alan Rickman), in a violent battle for Ireland's independence from Britain. But, when he fears the defeat of his revolution, Collins negotiates a treaty with the British, deeming him a traitor to the IRA. When he receives orders to murder his friends, Collins must decide where his loyalties lie.