Pinkerton has left for America, promising that he will return when the robins next build their nests. But 3 years have passed and Butterfly and Suzuki, the maid, are running out of money. The Consulhas continued to pay the rent, but there is no word from Pinkerton. Butterfly watches every US ship that arrives in the port in case it is his.Suzuki fears the worst and points out that it has never been known for one of these foreign husbands to return, but Butterfly insists that he will return if she keeps the faith.

Goro arrives with Sharpless, who has a letter from Pinkerton asking him to prepare Butterfly for bad news. But his attemps to read theletter are interurped at first by an over excited Butterfly – who misinterprets the letter as good news – and then by the arrival of Yamadori, awealthy man who is offering to marry her. Deserted women are acceptedas divorced, explains Goro. Not in her country, America, says Butterfly. She rejects Yamadori.

Sharpless decides to speak directly rather than read Pinkerton’s letter. What would she do if Pinkerton never came back? He advises herto accept the marriage offer from Yamadori. Butterfly runs from theroom and returns with her baby. It is Pinkerton’s, born after he left, and about which he knows nothing. He might forget her, says Butterfly,but he will return for his son. Sharpless promises to tell Pinkerton about the child. The canon sounds from the port announcing the arrival of a ship.It is Pinkerton’s. Butterfly and Suzuki prepare to welcome him back:they decorate the house with flowers and lanterns, and Butterfly dressesas she was on her wedding day. Night falls and still he doesn’t arrive.Butterfly remains awake all night. By the morning she is exhausted, andSuzuki tells her to sleep, that she will wake her when he arrives. While she sleeps, Sharpless arrives with Pinkerton. They have comeearly so that they can ask Suzuki to help tell Butterfly the truth.Suzuki sees a woman with them and asks who it is. It is Pinkerton’swife, Kate. Sharples asks Suzuki to talk with Kate, explaining that she is a kind person who will look after the child properly. Suzukiis astounded that they would ask a mother to give up her child, butagrees to the conversation. Pinkerton is filled with remorse. He doesn’t have the courage to stay and face Butterfly, prefering to leave it to Sharpless and Kate. Heasks Sharpless to give her some money, and rushes away. Butterfly wakes. She is frightened to see Sharpless and not Pinkerton,and demands to know if he lives, if he will return. Suzuki tells hertruth. Butterfly sees Kate, and understands quickly that this is his new wife. Kate asks her to give up the child. Butterfly says that she will give the child only to Pinkerton himself. Tell him to return in half an hour,she says, and he can take the child. Sharpless and Kate leave.Alone, Butterfly prepares to end her life. She looks her child inthe eyes for the last time hoping that somehow he will always rememberher, then blind folds him, and kills herself with the same sword her father had used.When Pinkerton returns for the child she is already dead. But what happened to their child? Did he live a full life in America? Was he curious about his roots? Did Pinkerton ever tell him about his mother, her life and her death? Or did he have to wait until his father’sdeath to piece together the distant memories and fragments of evidence he could find?