Lucien takes Aramis prisoner to set a trap for the Musketeers. Meanwhile, Treville meets with a recently returned Milady, and Sylvie receives a gift from Anne that soon proves anything but.
The Musketeers ride after Lucien and come to a camp where the women of a village have taken refuge while their men are off to war. The women harbor a dark secret that causes army looters to come after them.
Feron and Lucien set a trap for the Musketeers, but Athos escapes prematurely and rides to save his comrades. Meanwhile, Louis goes on a pilgrimage to celebrate the anniversary of the death of his father and takes Aramis along with him.
On the Dauphin's sixth birthday, Feron and Lucien engineer the theft of Louis' gold reserves to pay back the loan to the Dutch. However, things start to go wrong when Treville learns about the loan, and an escaped prisoner believing that he's Louis goes after Anne.
Henrietta, Queen of England--and Louis' sister--is robbed on the way to Paris. Louis sends the Musketeers to find the diamonds and the thief, as the diamonds were to be sold to fund the monarchy's war against Cromwell. Meanwhile, a childhood friends asks Aramis to give her away at her wedding, and an old friend of the Musketeers returns.moreless
Louis summons his brother Gaston, the Duke of Orlean, to the Royal Court. However, an incident as the Musketeers bring Gaston into Paris threatens to set off civil war.
After refugees from the war seek shelter in Paris, Feron uses them as scapegoats to conceal his own plan to steal the city's grain supply and sell it back through a third party to Louis at an exorbitant price. Meanwhile the Three Musketeers get used to being the Four Musketeers again as Aramis proves his worth.moreless
Four years after the Musketeers separate, Athos, Porthos, and D'Artagnan are fighting a desperate battle on the France-Spain battlefield. Meanwhile, nearby Aramis tries to save a monastery from brigands led by Lucien Grimaud, a war profiteer working with the new mayor of Paris, the Marquis de Feron.