The story of the last days of Paul, who went from being the most famous persecutor of Christians to the most influential apostle of Jesus Christ, awaiting execution by Emperor Nero in Rome under the watchful eye of Mauritius, the ambitious prefect of the Mamertine prison, who seeks to understand how this broken old man can pose such a threat. As his days grow shorter, Paul works from prison to promote the Gospel of Jesus Christ and encourages his followers to remain strong in their faith against Roman persecution.