During the Irish "troubles", an IRA gunman (John Mills) wearies of the constant violence. He begins to preach a philosophy of peaceful persuasion, and refuses direct orders to blow up a London railway station. The gunman's impatient brother (Dirk Bogarde) find his sibling's new approach to be counterproductive to the movement. The rest of the IRA agrees, and soon the gentle gunman is branded a traitor and a price is placed on his head. Based on the stage play by Roger MacDougall, Gentle Gunman was seldom seen once the Troubles were resparked in the Ireland of the 1960s.