Twenty years after their initial exploits, the aging musketeers find themselves divided by shifting political loyalties and the encroaching chaos of civil war. D'Artagnan and Porthos serve the interests of Cardinal Mazarin, while Athos and Aramis align themselves with the Fronde, placing the former comrades on opposing sides of a volatile conflict. As they navigate the treacherous landscape of 17th-century France and England, they must confront the vengeful Mordaunt, the son of their past adversary, Milady de Winter. The narrative follows their individual paths as they are drawn back into the service of the crown and the complexities of international intrigue.

Readers frequently highlight the shift in tone from the swashbuckling exuberance of the first volume to the more somber, reflective nature of this sequel. Discussion often centers on the complex moral dilemmas faced by the protagonists as they age and their personal loyalties are tested by the demands of the state. Critics often note the effectiveness of the historical backdrop, particularly the detailed portrayal of the English Civil War and the Fronde. The presence of Mordaunt as a formidable antagonist is frequently cited as a key element that drives the narrative tension throughout the book. Many readers appreciate how the author maintains the core character dynamics while allowing the protagonists to evolve significantly over the two-decade gap.