During the Irish Civil War in Dublin in November 1922 four Free State army soldiers led by Sergeant O'Conor flush out and capture an anti-Treaty sniper, Tom Beasley. Lieutenant Ashe arrives at the army barracks and during the night manipulates the soldiers into beating up the unarmed prisoner, despite O'Conor's objections. With Beasley almost dead, O'Conor finishes him off by shooting him.