Scene 1 – The Thebaid, on the banks of the Nile
Cenobite monks enjoy a modest evening meal outside their huts. Palémon, their leader, says a brief prayer, and all notice the return of Athanaël, one of their brethren. He is considered especially devout, due to the frequency of his dreams. He soon arrives, distracted by his notion of a corrupt city and the woman he admired in his youth, the scandalous courtesan, Thaïs. He had nearly succumbed to the temptation to visit her brothel before turning to God. Palémon warns of mixing with the outside world. They all pray and then go to sleep. Athanaël is suddenly awoken by a vision of a thinly veiled Thaïs performing on a stage. Convinced that she requires rescue, he vows to return to Alexandria to save her soul.
Scene 2 – The terrace of Nicias’ house in Alexandria
Athanaël approaches the home of his old friend Nicias, but is intercepted by a servant. The monk detests the state into which the pagan city has fallen – in his boyhood, it fared much better. Nicias rushes on to the terrace, and Athanaël proclaims his intention to bring Thaïs back to the Lord by having her enter a nunnery. The lecherous Nicias reveals that Thaïs will be dining at his home that very evening, following her stage performance. It is the end of a week-long tryst, which he can no longer support financially. Nicias lends his friend jewelry and a sumptuous robe to cover his bland, hermetic rags so that he can make a better impression on Thaïs. The slaves Crobyle and Myrtale both admire his natural beauty.
Groups of actors, actresses, and philosophers arrive. They idolize Thaïs after she makes her belated entrance. She espies Athanaël, who, Nicias ironically remarks, is there to convert her to his holy doctrine. She cajoles the cleric – she only believes in passion and no other power. Noticing the fire in his eyes, she believes he might be willing to forget his vows. After all, men were made for love. Shocked by her blasphemy, Athanaël threatens to follow her to her palace intent on bringing her back to spiritual health and redemption.
Scene 1 – The house of Thaïs
Gazing into a mirror, Thaïs admires her great beauty, but worries that she will eventually grow old. She concludes her soliloquy with a fleeting affirmation that she will be eternally beautiful. Athanaël arrives as anticipated and again makes his case – she must choose piety over lasciviousness, repent, and become a bride of Christ. He loves her in the spirit and truth only faith can bring, not in the lustful ways she already understands. Athanaël leaves, promising to wait outside until sunrise. Thaïs ponders her destiny – tomorrow she will only be a name – she will always remain Thaïs the courtesan. She meditates on the two prospects until dawn breaks.
Scene 2 – In front of Thaïs’ house
The next morning, Thaïs confesses the emptiness of her current way of life and resolves to follow Athanaël to Mère Albine’s remote hermitage. The first step is to destroy what is impure – setting fire to her sumptuous palace. Thaïs only wants to save one item – a small ivory statue of Eros that symbolizes the love she is forsaking. Athanaël insists that it be destroyed as well and smashes it on the pavement. They go inside.
Nicias appears on the terrace with his guests, who have reveled through the night. He has won at the gaming tables, and is able to engage Thaïs’ services once again. Nicias stages further entertainment, and after the dancers perform, La Charmeuse sings to the accompaniment of her lyre. Athanaël interrupts the merriment, announcing that Thaïs has left their sinful company – the Thaïs of hell is dead. She soon appears, disheveled and wearing a woolen tunic. The guests are aghast and beg her to stay, but then see flames licking out of the palace windows. The riotous mob threatens to kill Athanaël, but Nicias distracts them by throwing gold pieces to the ground, allowing Athanaël and Thaïs to escape unharmed.
Scene 1 – The oasis
As they approach the convent nestled in the desert, Thaïs falters from fatigue, her feet bleeding from the long journey. Athanaël finds food and shelter, and they rest. Mère Albine and Les filles blanches bring black bread and comfort. Confident he has achieved his purpose and not wanting to trespass on the sacred grounds of the convent, Athanaël leaves Thaïs in their care for a future of prayer and penance. Still, he is anguished by the fact that he will never see her again.
Scene 2 – The Thebaid
A storm brews in the distance. The monastic brothers remark that they haven’t seen Athanaël for twenty days – he has been in seclusion, fasting. His triumph over evil has broken both body and soul. Thaïs’ beauty still haunts his dreams, and her image taunts him with the possibility of love. Another hallucination reveals that Thaïs is on her deathbed. Athanaël vows to hold her one last time.
Scene 3 – The garden of Mère Albine’s nunnery
Les filles blanches pray for Thaïs’ salvation, her body destroyed by the atonement for her sins. Athanaël appears, pale and disheveled. Thaïs fondly recalls their journey, and Athanaël finally admits his eternal love. After a final shared moment together, Thaïs dies in beatitude while Athanaël comes to terms with his earthly passions.