In war-torn France, a sinister new battle awaits the Musketeers, as the swashbuckling hit series returns for a thrilling third installment. The royal bodyguards for Louis XllI, Athos, Aramis, Porthos and d'Artagnan are back to combat a dangerous new enemy lurking in the shadows of the city. It's a task that will challenge their allegiances to the crown, throw their personal lives into turmoil and compromise their loyalty to those they love, and to each other.