D'Artagnan, a spirited young man hailing from Gascony, finds himself nearly fatally wounded while attempting to rescue a young woman from being taken by a shadowy older woman and her ruthless henchmen. This harrowing encounter leads him to venture to Paris, where he aspires to enlist in the Musketeers of the Guard. Upon his arrival, he consults with Capitaine de Tréville, the esteemed commander of the musketeers, who, having known D'Artagnan's late father, offers to pen a letter of introduction for him.
However, as fate would have it, D'Artagnan spots one of his attackers in the streets below and rushes out to confront him. His audacity inadvertently offends three prominent musketeers: Athos, Porthos, and Aramis, each of whom demands satisfaction over the perceived insult. Thus, D'Artagnan boldly decides to duel all three that very afternoon.
As D'Artagnan gears up for his first duel, he comes to realize that Athos's seconds are none other than Porthos and Aramis. The pair, astonished by D'Artagnan's bravery, begin to admire his daring spirit. Just as the duel between D'Artagnan and Athos commences, Cardinal Richelieu's guards storm the scene, aiming to detain the four for illegal dueling. Outnumbered yet undeterred, the men band together and emerge victorious from the fray. The news of this escapade reaches King Louis XIII, who expresses his disapproval to the musketeers.
As D'Artagnan forges friendships with The Three Musketeers, he learns of Porthos’s bisexuality and soon finds himself enamored with Constance Bonacieux, who reciprocates his feelings. Constance is in the service of Queen Anne d'Autriche, a woman entangled in a secret affair with the English Duke de Buckingham. This clandestine romance poses a grave danger, with the scheming Cardinal Richelieu plotting to expose the queen’s betrayal, which could lead to dire consequences.
The narrative thickens as Athos is wrongly accused of murdering a young woman, discovered brutally slain beside him. D'Artagnan realizes this is the very woman he endeavored to save, and with The Three Musketeers, they embark on a quest to uncover the truth and rescue Athos from his grim fate. In a twist, he finds out that the enigmatic Milady, the woman behind the queen’s troubles, is masquerading at the House of Valcour.
In a gripping confrontation, Milady attempts to eliminate D'Artagnan, but he deftly escapes her deadly grasp. Athos’s life is spared by his brother Benjamin, who, with his Protestant allies, orchestrates a daring rescue. Meanwhile, the King presents the queen with a precious gift of diamonds, which she secretly bequeaths to her lover, Lord Buckingham. When rumors of the affair seep into the royal court, Louis XIII demands that Queen Anne don the diamonds at his brother’s wedding.
To salvage her honor, Constance dispatches D'Artagnan to England in a high-stakes mission to retrieve the diamonds from Buckingham. In a thrilling pursuit, D'Artagnan chases down Milady, who has stolen the jewels, ultimately reclaiming them just as she makes a dramatic escape. Returning just in time, he delivers the diamonds to Queen Anne.
At the climactic wedding of Gaston, Duke of Orléans, and Marie de Bourbon, Athos’s brother and Huguenot rebels attempt an assassination on the King. With valor and camaraderie, Athos and the musketeers thwart the attack, leading to the King's decision to pardon him.
As the first installment of this riveting tale draws to a close, D'Artagnan is struck unconscious in the street by one of Milady's henchmen while bravely striving to rescue Constance from another abduction. The intertwining arcs of friendship, loyalty, and treachery set the stage for an epic continuation.
