Aristide, Léandre, and Perrin pledge only three loyalties in life: their King, their captain, and their passion for each other. So when the musketeers discover a plan to accuse M. de Tréville of treason, the initial impulse to kill the messenger, Benoît, is tempered by their need to unmask the plotter. But their first two suspects, the English ambassador and Cardinal Richelieu, prove to be innocent, forcing the musketeers to delve deeper into the inner machinations of the French court.
Meanwhile, Aristide finds himself falling in love with the ill-fated messenger, a blacksmith without a home who rouses all of his protective, possessive instincts. Benoît, however, has no interest in any man. Torn between desire and duty, Aristide must find a way to protect the King and clear his captain's name—all while heeding the demands of his heart.

Read the story of the musketeers' friends, Teodoro Ciéza de Vivar and Lord Christian Blackwood, in Checkmate.