In 1625, the young D'Artagnan departs his Gascony village for Paris, carrying only his father's sword and a letter of introduction, under his grandparents' approval. The impoverished nobleman seeks an audience with Tréville, Captain of the Musketeers of the Guard and his father's former comrade, hoping to achieve heroism in the service of King Louis XIII.
Overwhelmed by the immense scale of Paris, the novice adventurer wanders the streets and befriends a young orphan named Jean. He inadvertently offends three Musketeers of the Guard: Porthos, Aramis, and Athos. After the Parisian guards intervene in their illegal duel, D'Artagnan and the trio repel five of Cardinal Richelieu's soldiers, forging a quick bond among the four.
These new comrades strive to prevent Cardinal Richelieu from igniting war between England and France and to safeguard the reputation of Queen Anne d'Autriche, Louis XIII's wife. Yet, what price will their endeavors exact?