When Anton O'Neill returns home after five years at sea, he finds that 1970's Ireland is a radically different place to the one he left behind. Northern Ireland is in flames, and civil unrest has spilled south of the border to his beloved home in County Cavan. Blinded by hatred and misguided patriotism 'Anton' is led into an illicit world of violence and is forced to choose between his family and his country. Hunted and on the run, Anton is drawn into a battle of wills with the law and his former accomplices, ending in a showdown in which he must risk everything to protect the woman he loves.

The real-life story of Dublin folk hero and criminal Martin Cahill, who pulled off two daring robberies in Ireland with his team, but attracted unwanted attention from the police, the I.R.A., the U.V.F., and members of his own team.