Sister Helen Prejean agrees to act as spiritual advisor to Matthew Poncelet, who is sentenced to death by lethal injection for raping and killing a teenage couple in Louisiana. Over many visits, she tries to understand the truth of his crimes and find evidence of his innocence before his execution. On the day of his death, Poncelet asks the victims' parents for forgiveness and says he hopes his death will bring them peace. The film explores themes of capital punishment, revenge, suffering, forgiveness, love, repentance, confession, and freedom through the perspectives of the convict, Sister Helen, and the families.