Well-respected Pompeiian Glaucus performs an act of kindness by purchasing Nydia, a blind slave being mistreated by her owner. Nydia falls in love with her new master, but he only has eyes for Ione. Ione in turn is lusted after by Arbace, an Egyptian high priest of Isis. When Nydia beseeches Isis for help in capturing Glaucus' heart, Arbace gives her a "love" potion-- an elixir made to drive Glaucus mad, securing Ione for himself. Ultimately, Mount Vesuvius will end their lives and seal their fates in a terrible, glorious eruption.

A patriotic drama played by one of the most beloved actresses of early Italian cinema: Mary Cléo Tarlarini is Mary, a high society lady who devotes all her dedication to the Italian patriotic cause, overseeing a war hospital and supporting the refugees. Luciano dello Stelvio, a young officer, falls in love with her, but after torments and family misunderstandings, he will sublimate his feelings in the love for his Country and will depart for the war, praised by Mary and by her daughter Emma, who had initially suspected them of having an affair.