When the bride-to-be of King Louis XIV is kidnapped, the sons of the original three musketeers rally to rescue her. Much to their surprise, a fourth musketeer joins the fray. And this brilliant swordsman—the most gifted of the lot—turns out to be D'Artagnan's daughter.

Indeed a tribute, this movie tells the story of Princess Diana's last year, from May 1996 to her fatal accident in August 1997. It focuses on her love affairs with a Pakistani heart surgeon and with Dodi Al Fayed, on her battle with the press, her charity work, and her relationship with her sons. Many scenes re-enact well-known images and moments from this year, and the movie ends on the note that Diana was about to accept Dodi's proposal of marriage when the accident occurred