Lucien launches one final attack on the Musketeers, and only with love and courage will they stand true... or die.

As Lucien leads the armies of Lorraine to the gates of Paris, Treville is forced to take extreme measures when he unexpectedly finds himself in a position of power.

Lucien abducts Aramis, who is secretly conducting peace negotiations for Anne with her brother Philip, as bait in a trap to kill the Musketeers. Meanwhile, Milady returns from England to be with Athos, and Sylvie is framed for crimes against the Crown.

The Musketeers pursue Lucien and find themselves in a camp of women waiting for their husbands to return from the war. Meanwhile, Anne begs Louis' forgiveness for the sake of France.

Lucien sets out to kill the Musketeers before they interfere further in his plans. He launches an attack on Athos and sets a trap for Aramis, Porthos, and D'Artagnan. Meanwhile, Louis goes on a pilgrimage, while Feron is forced to choose sides.

Lucien and Feron stage a prison breakout to cover Lucien's theft of the king's gold reserve. D'Artagnan befriends an insane prisoner who thinks that he's Louis, while Aramis and Constance discover that an imprisoned locksmith's wife is being held as leverage to force the man to assist in the robbery.

On a visit by the Queen of England, her jewels are stolen. By the purest of coincidence, the Musketeers find Emile Bonnaire in the city at the same time. Also, Aramis meets a friend from childhood who's about to be married.

Louis has the Musketeers bring his traitorous brother Gaston to Paris, despite the latter's exile, and extends the hand of friendship to the relative who tried to overthrow him. Meanwhile, the veterans of Paris grow restless when Louis refuses to pay their pensions. When Gaston loses a purse containing incriminating letters, Feron sees an opportunity to benefit himself.

Feron and Grimaud set out to turn the people of Paris against Louis by stealing grain and framing the war refugees. When D'Artagnan intervenes, he is arrested by the Red Guard. Meanwhile, Athos makes the acquaintance of a female refugee and revolutionary, and Anne receives word that Aramis has returned to Paris.

On the Spanish front, Athos, Porthos, and D'Artagnan find themselves outgunned when a supply train bearing gunpowder doesn't come through. They go to investigate and discover that a new player, Lucien Grimaud, is responsible. Meanwhile, Minister Treville and Constance deal with the new leader of the Red Guards, Louis' stepbrother the Marquis de Feron.