Reformer Jan Hus is burned at the stake for his heresy. An angry crowd jeers as he prophesies that they can roast the goose (Hus means goose) but God will awaken a swan whom they will neither roast nor burn. An Inquisitor asks when this will happen. Hus tells him he will answer in 100 years.
90 years later a young German law student, Martin Luther, is caught up in a dangerous thunderstorm. When a lightning bolt hits nearby, he drops to his knees promising to become a monk if St. Anne will spare him. He keeps his vow, much to the horror of his father Hans and mother Margarethe, who guilt him for not caring for them in their old age.
Enrolling in one of the harshest of monasteries in the region, Luther out-performs all his peers in acts of lowly service. He wears his confessor out with every little sin he can remember. When he spills wine while performing his first mass, and feels the horrors of hell awaiting him. Father Hans throws a party and insults him in front of all the monks, saying his call may be from the Devil, not God.
Upon his ordination as a priest, Luther is sent to the backwater university town of Wittenberg, where Elector Frederick owns the second largest collection of relics in the world. 1.9 million years of purgatory can be erased if one venerates every relic in Frederick’s collection. Luther soon becomes a popular professor and campus pastor in his new position, but by night the demons of doubt still haunt him.
To help him find peace with God, Luther's mentor Johann Staupitz sends him to Rome on monastery business. Maybe there, in the Holy City, Luther will finally find his illusive peace. But rather than peace, he finds hawkers of holy wares, prostitutes, drunken priests and a corrupt Pope with a larger gambling debt than the German treasury.
One night while studying the scriptures in the Black Tower, Luther stumbles across Romans 1:17: “The righteous shall live by faith.” He writes that he is born again, experiencing the grace of God in Christ for the first time. He begins to lecture, preach and teach with a new passion found in the grace of God… not in his own works.
Meanwhile in Rome, Giovanni di Medici bribes his way to be ordained Pope Leo X. With the world in chaos and the Church near bankruptcy, he raises funds to build a showcase church, St. Peter’s Cathedral. Leo sends the slickest Indulgence salesman in the world, Johann Tetzel, to Germany promising forgiveness of sins for a price.
Luther is angered by what he considers the corruption and un-Biblical practices of the church. On October 31, 1517, he nails 95 Theses to the Castle Church door, inviting a scholarly debate. Instead of a debate, a storm is unleashed that change the path of history.