In 19th-century Naples, Doctor Pisani is a patriot unjustly accused of having killed a marquise. He does not want to betray the cause and allows himself to be executed. Ten years later, his son Oliviero, who becomes an ophthalmologist, uncovers the truth and wants to marry Béatrice, the Marquise's daughter, who became blind during the assault on her mother's castle by revolutionary patriots.
