The Musketeers battle to restore order in Paris after Grimaud and Feron stage an ambitious Châtelet breakout, setting free a lunatic with murderous designs on the Louvre.

Young swordsman d'Artagnan arrives in Paris seeking the man responsible for killing his father – a quest that brings him into conflict with one of the king's guards. But as he quickly discovers, when you take on one Musketeer, you take on them all. It's soon back to business when the swashbuckling heroes are ordered to find a missing soldier who was carrying important letters on behalf of King Louis, while the dastardly Cardinal Richelieu plots to increase his political power.

Notorious criminal Vadim seeks to make life unbearable for the authorities that have imprisoned him. When he engineers a full-scale riot, it falls to the Musketeers to protect those whom he seeks to destroy.

Porthos wakes up after his drunken birthday celebrations with a dead body next to him. The Musketeers must prove his innocence as he gets sentenced to death.

The Musketeers help rescue an enemy's daughter in exchange for a deadly gunpowder formula.

The corrupt Governor of Paris conspires with the Duke de Beaufort, primary provider of food for Paris, to stage a robbery of the city's granary and pin it on the refugees, only to later sell the stolen grain back to the King at an inflated price. D'Artagnan is taken captive along with the rioting refugees, and the other Musketeers (along with D'Artagnan's wife Constance, now in charge of the Musketeer garrison) must rescue them from the hands of the Red Guard before they are executed.

Bonnaire is back, and the Musketeers need him to save the future of the English Crown.

Chasing Grimaud, the Musketeers make a troubling discovery in a village ruled by women.

The Musketeers must escort a merchant trader back to Paris and thwart his enemies.

A woman claims to have visions from God which instruct her to start a war with Spain.

King Louis tasks the Musketeers with bringing his exiled brother, the Duke of Orléans, back to Paris in order to mend bridges. On the way, the Duke is robbed of dangerous letters which could destroy Orléans. The Duke informs the corrupt Governor of this, and the Governor's Red Guard must race the Musketeers in the hunt for the thief.

Aramis helps an old friend to uncover the truth behind a disastrous mission.

The Musketeers must rescue a French general from an impenetrable Spanish prison.

Aramis and the other Musketeers help a young mother rescue her abducted baby son.

Athos must confront his past to protect the people he left behind.

The King’s cousin is ambushed while under Musketeer escort as she travels from Mantua to Sweden to make a political marriage that will be advantageous to France.

Athos, Porthos and D'Artagnan are fighting on the battlefront while Aramis has trouble living in contemplation as a monk. The Musketeers' search for missing gunpowder lead them to follow bandits to Aramis' monastery, where circumstance force them to collaborate to save the monastery's children and brothers. Aramis' finally accepts his true calling as a Musketeer and rejoins his brothers-in-arms in Paris.

The Queen's reputation is on the line after Grimaud kidnaps Aramis.

The musketeers help save an enlightened woman who has been accused of witchcraft.

A contest between the Musketeers and Red Guards gives D'Artagnan a chance to prove himself.

D'Artagnan must protect King Louis when a notorious criminal kidnaps them both.

Porthos uncovers the truth about his past and questions his allegiance to the Musketeers.

An astronomer gathers the royal party to see an eclipse, but events take a dramatic turn.

It's the day of reckoning, as Grimaud vows to kill the Musketeers in a series of savage co-ordinated attacks and puts Feron to the ultimate test in his bid for power. The furious battle for survival sparks a series of revelations that threaten to destroy Paris. Before the day is out, a hero falls, there’s a traitor on the rise and the Musketeers will be changed forever.

The Musketeers come under siege in a convent whilst protecting the queen's life.