It's 1649: Cardinal Mazarin (Philippe Noiret) hires the impoverished D'Artagnan (Michael York) to find the other Musketeers: Oliver Cromwell (Alan Howard) has overthrown the English King, so Cardinal Mazarin fears revolt, particularly from the popular Duke of Beaufort (Eusebio Lázaro). Porthos (Frank Finlay), bored with riches and wanting a title, signs on, but Aramis (Richard Chamberlain), an abbé, and Athos (Oliver Reed), a brawler raising an intellectual son, assist the Duke of Beaufort in secret. When they fail to halt the Duke's escape from prison, the Musketeers are expendable, and Cardinal Mazarin sends them to London to rescue Charles I (Bill Paterson). They are also pursued by Justine de Winter (Kim Cattrall), the avenging daughter of Milady de Winter, their enemy twenty years ago. They must escape England, avoid Justine, serve Queen Anne (Geraldine Chaplin), and secure Beauford's political reforms.