France, 1625. After a dalliance with the Duke of Buckingham, Queen Anne of Austria, consort to Louis XIII of France, presents the Duke with her diamond necklace. Informed of the Queen's indiscretion Cardinal Richelieu seizes the opportunity to discredit her and destabilize the throne. He dispatches Milady de Winter to seduce the Duke and steal back the necklace as proof of Anne's infidelity. The Queen's servant, Constance, enlists her lover, D'Artagnan, and his friends, the King's Musketeers, to retrieve the necklace, save the Queen, and foil the cardinal's plot.

A twist of fate leads a recent Westpoint grad into being responsible for the execution of two fellow American GIs. The young lieutenant comes of age, and the two battle hardened veterans achieve a state of grace through acts of sacrifice.