Teofane and Ottone are about to meet face to face for the first time, both looking forward to this, but Matilda suddenly appears and throws herself at Ottone's feet, begging him for mercy for Adelberto. Teofane withdraws into an alcove and watches as Ottone declines to pardon Adelberto but embraces Matilda in an attempt to console her. Teofane misinterprets this gesture as a sign that Ottone is in love with Matilda. In any case, the embrace does nothing to cool Matilda; she fulminates against Ottone for his refusal to show clemency to Adelberto, calling on monsters and furies to pursue him (Aria: "All’orror d’un duolo eterno"). When Teofane and Ottone finally meet, she accuses him of falsely pretending he is not in love with another (Aria: "Alla fama, dimmi il vero") and, once on his own, Ottone prays that this storm will subside (Aria: "Dopo l’orrore").