ACT I At the turn of the century, about forty-five years before an atom bomb destroyed it, the harbor town of Nagasaki was a very pretty place. On the outskirts of the town, and overlooking the harbor, is a pretty Japanese villa. In the garden, when the opera begins, there are a Japanese busybody and an American naval officer. The busybody is Goro, the marriage broker; the officer is Lieutenant Benjamin Franklin Pinkerton, U.S.N. Goro has arranged a marriage for the Lieutenant, and he shows him over the house that has been rented for 999 years (with, of course, a convenient cancellation clause). The marriage contract, by the way, has the same convenient clause - cancelable at a month's notice.

When the United States Consul, Sharpless, calls, he tries to persuade Pinkerton that there is danger in this arrangement, for Sharpless knows the prospective bride, her name being Cio-Cio-San, or Madam Butterfly, and he fears that the probably result will break her tender heart someday. But Pinkerton cannot be made to take anything seriously, and he even proposes a toast to the day when he will be really married--in the United States. And now it is practically time for the wedding ceremony.

Butterfly, accompanied by her relatives, makes her entrance as her voice soars above the close harmony of her female companions. She tells Pinkerton about herself and her family and her age - which is only fifteen - and she shows him various trinkets she carries in her large Japanese sleeve, including a dagger her father had used to commit suicide on the order of the Mikado. The general tone of the meeting, however, is very gay. The Imperial Commissioner performs the brief legal ceremony, and everyone sings a toast to the happy pair when suddenly, an ominous figure interrupts. He is Butterfly's uncle, the Bonze, a Japanese priest, who has learned that Butterfly has renounced her traditional religion in favor of Christianity and has come to cast her out. All the relatives side with the Bonze, and they turn on the young bride. But Pinkerton orders them all away; and in the long and wonderful love duet that closes the act, Butterfly forgets her troubles. Together Lieutenant Pinkerton and Madam Butterfly enter their new home.

ACT II Three years have passed quietly in Butterfly's house, but Lieutenant Pinkerton has not been heard from. Suzuki, who has been praying to her Japanese gods, tries to tell her mistress that he never will come again. At first Madam Butterfly is angry, but then she sings her famous ecstatic aria Un bel dì, describing in detail how one fine day he will sail into the harbor, come up the hill, and again meet his beloved wife. Soon there is an embarrassed visitor -- Sharpless, the American Consul. He has a letter he wishes to read, but Butterfly makes such an hospitable fuss over him that he cannot get going.

They are interrupted by the marriage broker, Goro, bringing with him the noble Prince Yamadori, who wishes to marry Butterfly. The lady politely but firmly refuses the Prince, whereupon Sharpless again tries to read the letter. Actually it tells of Pinkerton's marriage to an American girl, but the Consul does not have the heart to break the news - and so only a portion of the letter is read aloud in the Letter Duet. Instead, he asks what Butterfly would do if Pinkerton never returned. For a moment she thinks that suicide would be the only answer. Gently Sharpless advises her to accept the Prince. That is impossible, she insists, and she brings in the reason for the impossibility. It is her young son, named Trouble. But, she adds, he will be called Joy when his father returns.

Utterly defeated, Sharpless leaves. And now a cannon is heard from the harbor. An American ship - Pinkerton's ship, the Abraham Lincoln - has arrived! With joy Butterfly and Suzuki decorate the house as they sing their lovely Flower Duet. Then they prepare to await the arrival of the master. Through holes in the screen, Butterfly, Suzuki and Trouble prepare to watch the harbor throughout the night. A beautiful melody (used earlier in the Letter Duet) is played and hummed by an off-stage chorus, and the act quietly closes.

ACT III The beginning of the last act finds Suzuki, Butterfly and Trouble just where they were at the close of the second, excepting that the child and the maid are now sound asleep. It is morning and there are noises from the harbor. Butterfly takes her sleeping little boy into another room, singing him a lullaby. Into the garden comes the Consul Sharpless, accompanied by Lieutenant Pinkerton and Kate Pinkerton, his American wife. Suzuki almost at once realizes who this is. She cannot bear to tell her mistress, and neither can Pinkerton. He sings a passionate farewell to his once-happy home, and leaves. But Butterfly, coming in now, sees Kate and realizes that inevitable tragedy has struck her. With dignity she tells Kate that she may have her boy if Pinkerton will come soon to fetch him. Left alone with the child, she knows that there is only one thing to do. First she blindfolds him; then she goes behind a screen; and with her father's dagger she stabs herself. As she drags herself toward the boy, Pinkerton comes rushing back, crying, "Butterfly! Butterfly!". He is, of course, too late. He falls on his knees by her body as the orchestra thunders forth the fateful Asiatic melody heard before, each time that death has been mentioned.