Throughout the evening, the unsuspecting Duke amused himself with the pretty decoy, Maddalena; and the gipsy-girl at length became so fascinated with him that she could no longer bear to think of taking his life, and a feeling of pity for his fate took sudden hold of her heart. She was therefore filled with repulsion when her brother next appeared and invited the guest to retire to rest in the upper chamber set apart for him; and when, after a last tender glance at her, the Duke had mounted the rickety stairs and stretched himself on the couch above, she besought Sparafucile to spare the young man's life, declaring she felt a tender interest in him.
But Sparafucile muttered angrily that the hunchback's gold was more to him than the gay cavalier's life; and it was not until Maddalena again passionately implored him with tears in her eyes to grant her request, that he at length agreed on a compromise. He promised to spare the cavalier only on condition that some other stranger called at the inn before midnight, whom he could slay instead, and pass off to the hunchback as his victim; and with this, Maddalena was forced to be content, though she felt little hope of gaining her wish, since it was a stormy night, and no strangers were likely to call.
Now, the whole of this conversation between the brother and sister had been overheard by Gilda; for, though she had been to her home and changed her garments for male attire, according to Rigoletto's orders, she had been unable to resist the temptation to return to the inn that she might look once again upon the features of the man she still loved so dearly.
She arrived just in time to hear the gipsy-girl pleading for the life of the Duke; and realising that he was about to be murdered, she was overcome with horror. But on hearing the condition by which he might yet be saved, a wild enthusiasm filled her heart; and she resolved heroically that since her own life was ruined by a hopeless passion, she would sacrifice herself for the sake of her faithless lover.
Having commended her soul to Heaven, she calmly approached the door and knocked; and instantly there was a dead silence within. Maddalena trembled on hearing the sound; but Sparafucile drew his dagger, and upon a second knock being heard, he flung open the door and fiercely stabbed the supposed youth standing there. Gilda fell to the ground without a single word; and hastily producing a sack, the brother and sister fastened the body within it.
It was now midnight; and a few minutes later, Rigoletto entered, and paying down the remainder of the money promised, demanded his victim. Sparafucile produced the sack, and not wishing his trick to be discovered, suggested that the body should be immediately thrown into the river, and offered his assistance for this purpose.
Rigoletto, however, declined the offer, desiring to gloat over his victim alone; and when the bravo had reluctantly relinquished the sack, he dragged it a few yards distant, and then sat down to rejoice over his fallen enemy. But at that moment he heard the sound of a voice singing in the upper chamber of the inn; for the Duke had been awakened by the talking below, and was now indulging in gay snatches of song.
Instantly recognising the voice as that of the Duke, Rigoletto was filled with amazement and angry disappointment; and furious at having been thus cheated of his prey, he tore open the sack, and by the light of the moon beheld the beloved features of his own beautiful daughter!
Horror-struck, the poor hunchback lifted his child in his arms, and wildly implored her to speak to him once again; and Gilda, who was still breathing, opened her eyes and murmured a few words, saying that she had willingly given her life to save that of her lover.
She then sank back, dead, in her father's arms; and Rigoletto, suddenly remembering the curse that had been laid upon him for having mocked at a distracted parent's grief, realised that his retribution was just, and, with a despairing cry of woe, fell senseless beside the prostrate body of his beloved child.