Ngoc Minh Quan, a widowed former Vietnam War special operations forces soldier, runs a Chinese restaurant in London with his business partner Lam and his teenage daughter Fan. When Fan is killed in a terrorist bombing, Quan seeks revenge. An Irish republican group calling itself the "Authentic IRA" claims responsibility. Quan takes to visiting Scotland Yard daily, asking for names of the bombers, but is told by police chief Commander Bromley that his repeated visits are diverting resources away from the investigation. Bromley advises Quan to be patient and warns him against going after the IRA. Undeterred, Quan takes matters into his own hands and next focus on the Northern Ireland deputy First Minister and Sinn Féin politician Liam Hennessy, who speaks publicly about his status as a former Provisional IRA leader while outwardly claiming to condemn the attack. Quan purchases items to make homemade weapons and travel to Belfast, leaving the restaurant under Lam's control.