Fra Cristoforo has a dark secret: once upon a time, he killed a man. Originally, his name was Lodovico, and he was the son of a rich merchant. One day he was out walking with his loyal, faithful servant Cristoforo when the two men got into an argument with a nobleman. In the ensuing fight, Cristoforo was killed by the nobleman, who in turn was killed by Lodovico. Immediately, Lodovico ran away to seek sanctuary in a monastery, where he took the name Cristoforo in tribute to his fallen servant. From that moment on, Fra Cristoforo has devoted himself to God, a devotion that manifests itself in his fatherly concern for the welfare of the two young lovers at the center of the story, Renzo and Lucia.