ACT I The Imperial City of China, outside the walls of Peking
The Princess Turandot has vowed that she will only marry the man of royal blood who shall solve the three riddles she has set. If he attempts and fails, he will be beheaded. A crowd of people fills the square as a Mandarin reads a proclamation to that effect and announces that The Prince of Persia has just failed in his attempt and will die at moonrise (Popolo di Pekino — People of Peking). The excited crowd calls for the executioner but is beaten back by the guards. Timur, the blind, deposed, Tartar king, and Liù, his Chinese slave girl, have concealed themselves amongst the crowd. In the confusion, Timur falls and, when Liù asks for assistance, an Unknown Prince offers to help. He recognizes Timur as his father and explains he is incognito because their enemies are searching for them both. Timur tells his son of his flight, accompanied only by Liù who has offered to guide him. When the Prince asks her why she has risked her life, she tells him it was because he once smiled at her.
As the executioner sharpens his sword, the populace, impatient for the rising of the moon, cries out for the blood of the Persian Prince. However, when he appears, his youth and sad expression draw pleas for mercy. Calàf joins them, speaking of Turandot as evil and cruel. Then she appears, and her radiant beauty captures his heart. Even when she gives the signal for the execution of the Persian, the Unknown Prince remains under her spell. In spite of the pleas of Timur and Liù, he runs toward the gong that announces potential suitors. The Emperor's ministers, Ping, Pang and Pong, appear and also try to dissuade him by describing the horrible death that awaits him if he fails. After all, Turandot is merely a woman; there are many others.
Turandot's ladies enter and demand silence, their mistress is resting. They exit and the Unknown Prince, urged on by the ghosts of former suitors, persists in his desire to try to answer the riddles. Once more, Liù pleads with him (Signore, ascolta — Sir, listen). He tries to comfort her (Non piangere, Liù — Don't cry, Liù) but, enchanted by the vision of Turandot, and calling her name, he strikes the gong.
ACT II
Scene 1 A pavilion in the palace.
Ping, Pang and Pong talk of the sorry state of China and how, until the birth of Turandot, all was in accord with the ancient rules. Reduced to being merely ministers of the Executioner, they recall the many deaths of suitors: eight in the year of the dog, six in the year of the rat and, in the current year of the tiger, already thirteen, including, they suppose, the Unknown Prince.They long for the time when Turandot will finally succumb to a lover.
Scene 2 A square in front of the Imperial Palace.
As the people congregate, the great drum and trumpets are heard signaling the ceremony of the riddles. The Emperor Altoum, is hailed by the crowd as the 'Son of Heaven' and with their wishes for him to live ten thousand years. He is accompanied by eight Wise Men who carry scrolls with the answers to the riddles. The Emperor regrets the oath he swore to uphold the law which causes Turandot's suitors to lose their lives, and he tries to discourage the Unknown Prince; he has witnessed too many deaths. When the Prince refuses to heed his warning, the Mandarin again reads the law. Turandot enters; she tells of her ancestress Lou-Ling, who was abducted and killed and killed by the Tartars two thousand years ago (In questa reggia — In this kingdom). Turandot now takes revenge on all who seek to possess her. She asks the three riddles. "What is born anew every night and dies at dawn?" The Prince answers: "La speranza — Hope". "What kindles like a flame but is not a flame?". He answers: "Il sangue — Blood". Finally, "What is ice which gives you fire?" Triumphantly he responds: "Turandot". As the people hail the Prince, a stricken Turandot begs her father not to give her to the stranger. However, the Emperor replies that his oath is sacred. The Prince offers that, if she can discover his name before he will release her from her oath and allow himself to be executed. Turandot accepts the challenge.
ACT III
Scene 1 The gardens of the palace.
It is just before dawn, but all in the city are awake. Turandot has decreed that there will be no sleep unless the name of the prince is discovered. If it is not, all will be killed. The Prince sings his aria Nessun dorma (None shall sleep). The people threaten him, demanding to know his name so that they will not be tortured. Ping, Pang and Pong do their best to persuade him to flee and save his life, even tempting him with beautiful women and treasure. As soldiers bring in Liù and Timur, Turandot appears and demands the name of the Unknown Prince, threatening to torture Timur for an answer. To save him, Liù pretends that she alone knows the name but refuses to devulge it. She is tortured but still refuses to tell the name. When Turandot asks what force enables her to keep silent, Liù answers that it is love (Principessa, ascoltami! — Princess, listen to me!) and predicts that Turandot will come to love him also. Fearing she may break down, and determined not to reveal her secret, Liù siezes a dagger from a soldier and stabs herself. As the people call for his name, she staggers to the Prince and falls dead. Confused, the blind Timur kneels, pleading with her to get up, and is told she is dead.Her body is carried away, and all follow. (It is at this point that Puccini left the opera unfinished.) The Prince is left alone with Turandot. He rushes to her, tears away her veil and, in spite of her protests, kisses her passionately. The icy Princess melts in his arms. As dawn breaks, she tells how she had despised the many others who had died, but that she both hated and feared him. She has been conquered by him (Del primo pianto — From my first tears). The Prince, knowing he has won her, reveals his name; he is Calàf, the son of Timur.
Scene 2
The emperor and his court await Turandot's news. She tells her father she knows
the stranger's name: His name is Love!" All rejoice as Turandot and Calàf
embrace.