Act 1

The castle of the marquis de Cinq-Mars

A choir of noblemen celebrates the imminent importance Cinq-Mars is going to take ("A la Cour vous allez paraître"); some suggest that he owes his debt of allegiance to the Cardinal of Richelieu, and others to the King. For his part, Cinq-Mars shows himself indifferent to the questions of political order. Alone with his closest friend, de Thou, he confesses that he loves princess Marie de Gonzague ("Henri! Vous nous parliez"). They recognize both intuitively that this affair will end badly. The guests reappear: among them is Father Joseph, the spokesman for the Cardinal of Richelieu, and the Princess Marie. The first one announces that Cinq-Mars is called to the royal court, and that a marriage is arranged between Princess Marie and the King of Poland. Cinq-Mars and Marie agree to meet later in the evening. After the departure of the guests, Marie wishes her heart to be at peace in the sweetness of the night ("Nuit resplendissante"). Cinq-Mars walks in and declares his love to her; before he leaves, she declares herself in turn ("Ah! Vous m'avez pardonné ma folie").

Act 2

Scene 1: The King's apartments

After a choir sings the beauty of courtesan Marion Delorme ("A Marion, reine des belles"), Fontrailles, Montrésor, Montmort, de Brienne, Monglat, and the other courtesans discuss the increasing influence of Cinq-Mars over the King. The nobles are dissatisfied with the excessive power that the Cardinal of Richelieu has assumed, and they wonder if Cinq-Mars will join finally their cause. Marion reports that the Cardinal threatens to exile Cinq-Mars; Fontrailles is surprised, and is sure that Paris would become very boring without its elegant salons ("On ne verra plus dans Paris"). Marion announces that she will organize a ball the next day, which will give them the opportunity to cast the basis of an intrigue to eliminate the Cardinal. Cinq-Mars appears and is welcomed by the courtesans ("Ah! Monsieur le Grand Ecuyer"). Marie has just arrived at the Court, and the two lovers are reunited ("Quand vous m'avez dit un jour"). However, just after this blessed moment, Father Joseph comes to announce that, in spite of the King's informal agreement of Cinq-Mars's marriage with Marie, the Cardinal refuses to formalize their union, preferring rather to follow the original plan of marrying Marie to the King of Poland.

Scene 2: At Marion Delorme's apartments

The evening begins with the reading of Madeleine de Scudéry's last novel, Clélie, followed by a long pastoral entertainment with ballet, including notably a sonnet sung by a shepherd ("De vos traits mon âme est navrée"). More serious things are on everyone's mind, however ("Viendra-t-il?"). Fontrailles assures everyone that Cinq-Mars will join the plot, as he predicted, and that Cinq-Mars will arrive soon. He declares that the King is no longer in total control of the country, and that the eviction of the Cardinal is a just cause; civil war is imminent, and he assures his co-conspirators that he arranged a treaty with Spain, which implies that their armies will intervene on their side. De Thou suddenly interrupts him, and warns him against opening France up to a foreign power, but the marquis remains resolute.

Act 3

The next day. Outside of a chapel

A meeting of the conspirators is imminent. Marie appears, contrary to all expectations, and agrees with Cinq-Mars to immediately exchange wedding vows ("Madame, c'est le lieu du rendez-vous"). After their departure, Father Joseph and Eustache appear from a hiding place: Eustache is a spy and makes a complete report of the intrigue to Father Joseph. Father Joseph savors the power which he possesses on the fate of Cinq-Mars ("Tu t'en vas"). He confronts Marie with the announcement of the execution of Cinq-Mars, for betraying the country by dealing independently with a foreign power. Further, he tells her, the Polish ambassador will return soon from a hunt with the King, and Father Joseph advises Marie to answer him favorably; in exchange, Cinq-Mars will be spared. When the royal suite arrives, Marie capitulates ("Hallali! Chasse superbe").

Act 4

A prison

As he waits for execution, Cinq-Mars regrets that Marie abandoned him; nevertheless, his last hour approaching, he evokes her image by way of consolation ("O chère et vivante image"). Marie enters, explains the guile of Father Joseph, and admits that she always loved Cinq-Mars ("Ah! Qu'ai-je dit"). De Thou draws up the plan which has been prepared for the escape of Cinq-Mars the next day. When the chancellor and Father Joseph come to announce that the marquis will die before the dawn, it becomes clear that this plan will not happen ("Messieurs, appelez à vous, votre courage"). Before Cinq-Mars is brought to the gallows, he sings with de Thou a final prayer.

Sources

• Noël, Edouard [in French]; Stoullig, Edmond [in French] (1878). Les Annales du théâtre et de la musique: troisième année (in French). Paris: Paul Ollendorff. OCLC 1772186.