Set in 17th-century northern Italy, the novel tells the story of Renzo and Lucia, two young lovers who are prevented from marrying by a powerful nobleman, Don Rodrigo, who desires Lucia for himself. Forced to flee their village, the couple becomes separated.
Each of them faces great hardships, including war, famine, and the devastating plague in Milan. Along the way, they encounter both cruelty and kindness, with figures such as Fra Cristoforo helping them in their struggle.
After many trials, Renzo and Lucia are finally reunited. Don Rodrigo’s power collapses, and justice is ultimately restored. The story ends with their marriage and a hopeful new beginning.