massimo, at the capitol, is trying to instigate a popular revolt against the emperor, who appears, alone and in despair at fulvia's supposed betrayal. massimo attempts to kill the emperor, but fulvia suddenly rushes in and throws herself between her father and valentiniano, saving his life. varo enters with ezio, to general astonishment. valentiniano can see now that fulvia and ezio really love each other and that he was wrong to try to part them. they will marry, and valentiniano agrees to ezio's entreaty for him to pardon the repentant massimo. all celebrate the fortunate outcome of events.