Director Hirschbiegel's tense thriller begins in 1975 during The Troubles in Northern Ireland as 17-year-old Alistair Little (Davison) tries to earn his stripes via an anti-Catholic assassination, initially unaware that the victim's 11-year-old brother Joe Griffen (O'Neill) witnesses the slaying. Based on fact, the story steps ahead three decades to the fabricated scenario of Griffen (Nesbitt) and Little's (Neeson) planned face-to-face meeting prompted by a TV reality program looking more for ratings than amends. After serving 12 years, Little now thrives in the field of conflict resolution, and hopes to reconcile, whereas behind Griffen's seemingly normal life masks a broken man seeking revenge, dubbed his "five minutes in heaven." Told in three parts, screenwriter Hibbert plays out this "what if" scenario with guidance from the real Alistair and Griffen.