The former musketeer Athos swears vengeance after despotic King Louis XIV causes the death of his son. Summoning his old comrades Porthos and Aramis, he hatches a plan to liberate a shackled prisoner rumored to be the king's twin brother, and then install him on the throne. But the three musketeers must also contend with their old friend D'Artagnan, who has remained in the king's service.
