Cardinal Richelieu plots at the court of Louis XIII, trying to control the queen who secretly loves the Duke of Buckingham. D'Artagnan, a man from Gascony, arrives seeking adventure and joins the King's Musketeers. He proves his sword skills and forms a lasting bond with Athos, Porthos, and Aramis, the Three Musketeers. After many thrilling experiences, he embarks on a risky journey to England to retrieve the diamond brooch, which the queen had given to Buckingham as a sign of love. He succeeds and returns just in time to protect the queen from Louis's anger, overcome Cardinal Richelieu's scheme, and win Constance, the queen's dressmaker.