Aspiring swordsman D’Artagnan (Gene Kelly) arrives in Paris with hopes of joining the royal guard and falls in love with the beautiful Constance (June Allyson). After clashing with three of the king’s musketeers, Athos (Van Heflin), Porthos (Gig Young) and Aramis, he joins them in fighting the forces of corrupt Richelieu (Vincent Price). When Richelieu attempts to undermine the throne and fan the flames of war, D’Artagnan and the musketeers must thwart his plans.