The couple comes out of the cabin, observed by Arturo, who overhears that they plan to leave together the next day. Arturo concludes that they are lovers, and after Alaide has returned to her cabin, he confronts Valdeburgo furiously and demands revenge. The men fight a duel, Valdeburgo is wounded, and he falls into the lake. Alaide then appears and Arturo declares that he has killed his rival, but Alaide, heavily shocked, reveals that Valdeburgo is actually her brother. Upon hearing that news, Arturo jumps into the lake in an effort to save Valdeburgo. Attracted by the shouting, a crowd finds Alaide standing with Arturo's bloody sword, and they accuse her of murdering Valdeburgo. She is dragged off as a prisoner.