The story is set on Lake Como and follows the love story of Renzo and Lucia, who want to marry but their plans are disrupted when Don Abbondio is threatened by local bullies not to perform the ceremony. Lucia is then kidnapped by the villainous Inominato but is later freed after he repents. A plague breaks out and many get sick, including Renzo, though he recovers. Renzo and Lucia reunite and are finally able to marry, bringing their story to a happy conclusion.