After a brief orchestral sinfonia, Adelberto, Emireno and Teofane appear with their guards. Their escape has been stalled by a sudden squall that has blown up. Adelberto hopes both for better weather and for Teofane's love (Aria: "D’innanlzar i flutti al ciel"). He leaves to look for a dwelling where they can take refuge from the storm. Alone with Emireno, Teofane demands respect as the daughter of Romano, King of Byzantium. At this, Emireno attempts to embrace her, and Teofane, as well as Adelberto who returns just as this takes place, misinterpret the action as an attempt at seduction. Adelberto attacks Emireno but the guards seize him. Teofane is distraught and asks the guards to kill her, death will be a release (Aria: "Benchè mi sia crudele"). Emireno tells her she has no reason to be afraid (Aria: "No, non temere, o bella"). Teofane imagines Ottone in Matilda's arms, but even so, she swears she will love him always (Aria: "Gode l’alma consolata").