Having disposed of his enemies, Lucio Silla is now all-powerful. He wants to marry Giunia, but underestimates how much she hates him. After all, he has not only had her father murdered, but has also banished her beloved, Cecilio. At first, Giunia is misled into thinking that Cecilio is dead; with the help of Cinna, however, the lovers manage to meet up again. The power of love and Cinna’s machinations finally persuade Silla to relinquish his power.