The main characters in this opera by Verdi are Ricardo, the governor of Boston, his bosom friend Renato and Renato's wife, Amelia. Ricardo and Amelia fall deeply in love but their affair remains platonic. Through a series of fatal, successive events, Amelia's husband will find out about their romance and, blinded by jealousy and hatred, he will collaborate with Ricardo's enemies and plan his assassination. In fact, the luck of the draw will have him as the assassin. So, when Renato is invited to a masked ball at Ricardo's house, he approaches him and stabs him. On his deathbed, Ricardo will ask for his friend not to be punished, thus proving that he at least did not betray him.