The Franconian Earl of Buttlar is the father of two sons: Fritz and Ludwig who differ from each other in their characters. Fritz, the elder one, loves the excess and gets into bad company, a combination that soon forces him to escape together with some of his accomplices. In the meantime Ludwig knows how to make the immoral conduct of his brother appear in an even worse light. In desperation, Fritz gets involved in a gang of robbers and becomes their leader. The old Earl has a niece, Maria, who is fondly in love with Fritz. She resists Ludwig's hot pursuit whilst the blood-thirsty deeds of Fritz gradually become known. His sword terrifies the tyrants, the despots and the vile servants of justice, but it protects the poor and oppressed. He rescues the prisoners but is caught in an ambush with his gang. While Fritz succeeds in escaping, Ludwig is mortally wounded.