In this final volume of The Three Musketeers series, Aramis plots a coup d’état to replace Louis with Philippe and recruits Porthos to assist, although Porthos is unaware of the true nature of the plot. Aramis believes that, if he puts Philippe on the throne in place of Louis, Philippe can assure Aramis's promotion to cardinal, and will eventually assist Aramis to become Pope. Aramis's further aim is to enhance Fouqet's position in France so that Fouquet will become prime minister under Philippe; Aramis plans to replace Fouquet as prime minister upon Fouquet's retirement.