It is Chérubin’s 17th birthday! He is gaining his official title of Marquis (second in hierarchy only to a Duke) and has also inherited a massive amount of land and the responsibility of caring for the people who work on and cultivate the land. Chérubin’s tutor and life mentor, the Philosopher, is arranging the festivities for the exalted guests who will arrive any minute.
The Duke, the Baron, and the Count enter and remark how they hate Chérubin and hate having to be there but their wives forced them to join in the party. The Duke’s ward, Nina arrives and she and the Philosopher discuss Chérubin with whom Nina is deeply in love. The Duke and the Baron return to disclose that Chérubin has invited the most famous dancer in the world, L’Ensoleillad, to dance at the party.
Chérubin enters, teases the grumpy Duke and Baron, and announces that L’Ensolleilad will, indeed be performing at his party. The Countess and the Baroness enter. Chérubin makes a beeline for his beloved Countess and tells her to look for a love poem which he has hidden in a knothole in a willow tree. The Count overhears the conversation and goes to find the poem. The other party guests arrive and all are entertained by a group of “peasant” dancers. After the dance, the guests are ushered into Chérubin’s estate home for dinner.
Chérubin confides to the Philosopher that he is bothered by the most insignificant items. The Philosopher responds that Chérubin is not sick, he is simply in love. Chérubin leaves as the Count storms in with the love poem that he has found in the willow tree. He announces that he is going to kill Chérubin. The Countess and Nina enter and the Count confronts the Countess with the poem. Nina tells the Count that the poem is not intended for the Countess but for herself. She then recites the poem from memory. The Count apologizes to Nina and the Countess, who is livid that Chérubin is in love with Nina. The Philosopher is overjoyed. Chérubin runs in and announces that he is in love! The Philosopher remarks that he is ecstatic for Chérubin’s choice until Chérubin announces that he is in love with L'Ensoleillad, who has just arrived.
At a high-end country hotel, a group of travelers tries to get rooms for the night. The hotel manager tells them that they aren’t high-class enough for his hotel and they should sleep in their cars! He and his staff then throw them all out. The Baroness and Countess arrive and ask about their rooms. The Countess wants the luxury suite, overlooking the courtyard. The hotel manger tells them that that room is reserved for L’Ensoleillad, at which news the two women fly into a rage. The Count and Baron arrive and tell their wives to be quiet, that this is a matter of the highest importance. The Duke arrives and all freeze. The Duke, as emissary for the King of Spain, enquires about the room for the “special” guest. He then exits as do the other four titled people.
A rowdy group of soldiers, led by their Captain, Ricardo, and local women arrive. They have come to meet the newest standard-bearer for their regiment. All of the women are very interested to meet the new soldier. Chérubin enters and the women flock to him. Ricardo is very jealous and tries to pick a fight with Chérubin, who deflects all of the Captain’s bravado. Suddenly, L’Ensoleillad arrives although only Chérubin and the hotel manager know who she is. L'Ensoleillad and Chérubin share a rather intimate encounter. Ricardo interrupts them and the fight seems inevitable until L'Ensoleillad and the Philosopher break it up. The Philosopher asks Ricardo to remember being seventeen and a walking hormone. Ricardo is moved and he and Chérubin shake hands.
The hotel manager announces that the mysterious lady just there was none other than L'Ensoleillad. All are concerned that the King might punish them. L’Ensoleillad re-enters and assures them that they have nothing to worry about. She tells them to drink to life and love. She then decides to dance for them, during which a number of the locals join in. After the dance, she bids them all adieu, regretting that her freedom is about to end as tomorrow she is going to marry the King.
Chérubin sings to the Philosopher of his insatiable love for women. The Philosopher leaves as L'Ensoleillad appears on her hotel balcony. Chérubin sings to her of his youth and “inexperience”. L'Ensoleillad comes down into the garden and makes the decision to have one final moment of pure joy before going to marry the King. She leads Chérubin off into a wooded area.
The Duc, Baron, and Count arrive, searching for Chérubin. They exit. L'Ensoleillad, having heard the three men run on, fears that she and Chérubin might get caught. Chérubin runs off to lead the three fools through the woods, away from the hotel. L'Ensoleillad appears once more on her balcony, hoping that Chérubin will return which he promptly does. He manages to climb up to her balcony and they have one, final, glorious moment together. The Countess and the Baroness appear on their balconies. Chérubin scrambles down to the courtyard asking for a token of love from all the three ladies. They respond immediately just as the Duke, Baron, and Count run in. They think they have him! The hotel manager calls for the police and the police arrest the Baron and the Count while the Duke has a fit.
The next morning, the Philosopher finds Chérubin writing his will. He leaves Nina a ring, his entire fortune to L'Ensoleillad, and his properties and estate house to the Philosopher. The Philosopher will not hear of Chérubin dying. He decides to teach Chérubin some of the finer points of hand-to-hand combat.
The Countess and Baroness enter and demand to know for whom Chérubin was singing the previous night. He admits that he was singing for L’Ensoleillad. The two women rebuff Chérubin just as their husbands enter. The Countess tells Chérubin that they are through unless he helps them to get their husbands off of their backs. Chérubin publicly admits that he was singing for L'Ensoleillad. The Baron and the Count, contrite, whisk their spouses away, all four mocking Chérubin.
The Duke comes charging in with a message from the King for L’Ensoleillad. Chérubin realizes that L'Ensoleillad is his last hope for happiness. L'Ensoleillad is heard singing a song about love (which is the urgent message from the King). As L'Ensoleillad leaves for Madrid, Chérubin begs her to remember the night before and to not leave him without hope. She barely recognizes him and is rushed off to become the new Queen of Spain. Chérubin, crushed, swears off of women and love forever. The Philosopher, his beloved mentor and life guide, manages to calm Chérubin down.
Nina enters. She announces that she is going to enter a convent. She had accepted Chérubin’s endless flirting and womanizing as youthful recklessness. Now, however, she realizes that she had been foolish and perhaps used. In a flash, Chérubin realizes that Nina is his true love. They sing joyfully that life is about loving, feeling, and suffering. The Duke enters, enraged to find his ward in the arms of Chérubin. Chérubin proposes to Nina. Ricardo arrives and begins to take Chérubin to his deployment. Chérubin runs back in and puts the ring he had promised Nina in his will on her finger. He runs out as Nina is left to ponder her future.