Alexander Dumas crowns his trilogy with an authentic masterpiece in which for the first time he presents the man in the iron mask that starts with The Three Musketeers. Ten years have passed since the moment in which it closed twenty years before, and Dumas presents the final days of cardinal Mazarino, being already D'Artagnan captain of the musketeers. His objective, along with his faithful companions, is to lead Carlos II to regain the throne that his late father lost. However, their paths have forked: Porthos tries by all means to climb the French social ladder; Athos struggles to avoid the incipient relationship of his son Raoul with the beautiful Louise de La ValliÈre (who is in love with the young King Louis XIV), and Aramis, the visible head of the Jesuits, has discovered the existence of a hidden brother of the young monarch.