Act I
English colonial oppression looms over India. The Hindus appeal to Brahma and his children, the gods Durga, Shiva and Ganeshа, in hopes of deliverance. In their struggle, they аre guided by the High Priest Nilakantha. He also dedicated his daughter Lakmé to the gods – a priestess in the secret temple, hidden deep in the dense forest. After the service, Nilakantha leaves for the city to prepare for the upcoming religious holiday. He entrusts his daughter to the servant Hadji and her friend Mallika. The two girls, intoxicated by the beauty of the fragrant nature, go for a walk in the woods.
Meanwhile, the temple was invaded by the noisy company of Governor Ellen's daughter, her friend Rose, Governor Mrs. Bentson, and the officers Gérald, Ellen's fiancé, and his friend Frédéric. They look with interest at the secret refuge of the Hindus and listen to Frédéric’s story about Lakmé – the daughter of the priest, whom he hides here in this heavenly place. The young officer warns his friends not to desecrate the temple. But Gérald dares to stay to sketch Lakme's jewelry left in front of the altar. In his imagination he sees the image of the girl and begs "the vision with golden wings" not to disturb his spirit…
Lakmé and Mallika return from the forest. Despite the restlessness of her soul today, Lakmé feels happy. When she sends Hadji and Mallika to meet her father, Gérald comes out of his hiding and warmly admits his feelings. Despite the ban, love for the handsome officer burns in the girl's heart. Hidden nearby, Hadji managed to see the two lovers and inform the Hindus. Nilakantha comes, led by the servant. The priest swears that bloody revenge awaits Gérald, who has dared to defile their faith.
Act II
Many people have gathered at the city market – citizens, merchants, thieves, beggars, sailors, dancers. Gérald is here with his company. Among the crowd are Lakmé and Nilakantha, disguised as a hermit. The girl tries to divert her father from his intention to take revenge on the Englishman – "Will Brahma rebuke us, if we forget the insult?" The insult inflicted by a non-believer cannot go unpunished! Nilakantha orders his daughter to sing to entice Gérald. Indeed, knowing his beloved, he ignores his friend Frédéric's warning and the call of the soldier's trumpet – "Let me look at her a little longer!" Nilakantha reveals his plan to the conspirators – "My blessed hand will fulfill the sacred task!" He entrusts his daughter to Hadji, who, having understood Lakmé's great pain and sorrow, assures her of his devotion to her - "If you have a friend to save, order!"
In his brief meeting with Gérald, Lakmé convinces him to accept her faith and follow her to the forest, where, hidden from human view, they will live happily… "You want me to hide, but you don't know that duty and honor keep me here. You better wish me life," Gérald replies. The religious procession is approaching. The two lovers separate. Gérald is impressed by his meeting with Lakmé and admits to Frédéric that the priest's daughter is just a vision for him, but fears that the image of the girl is alive in his heart. At this time, the conspirators begin to carry out their plan – Gérald is wounded. But Lakmé and her faithful servant Hadji save him. "Lord, protect our love!" Lakmé pleads with God.
Act III
In a hut hidden in the thick forest, Lakmé takes care of the wounded Gérald. The song of the lovers can be heard in the distance. They are walking to the sacred spring, which bestows eternal love. Lakmé convinces Gérald to drink from the water too. This will bind them forever, and good goddesses will watch over their lives. Lakmé goes to the spring.
To Gérald comes Frédéric, who has reached the hut, led by the drops of blood on the blue meadows in the forest. He reminds his friend of the military duty – their regiment will soon engage in battle with the rebellious Hindus. Gérald agrees to leave, and reassured by his friend's decision, Frédéric leaves him to meet Lakmé, who is returning from the spring. The girl feels the change in Gérald - "His heart turned… It's all over!" Realizing that she is losing her lover, she swallows poison and desperately wants Gérald to drink from the spring water in confirmation of his words that he gives up everything and will be only hers forever. The young man takes the glass of miraculous water from the hands of the dying Lakmé.
Nilakantha is coming. He renounces his intentions to kill Gérald because he learns from Lakmé that the water from the spring has already connected them in a sacred union. Lakmé dies, and Nilakantha soothes the pain of losing his beloved daughter by believing that by leaving their enslaved country, she will take their prayers to Heaven…