In the final act, Fiora's body is laid in a crypt, and the people of Altura mourn for her. Archibaldo has secretly poisoned Fiora's lips, so that her lover will die.
As the story concludes, Fiora's corpse is interred in a mausoleum, prompting the citizens of Altura to express their sorrow. However, unbeknownst to them, Archibaldo has surreptitiously tainted Fiora's lips with poison, guaranteeing her lover's demise.