King Louis' sister, Queen of England Henrietta Maria, is robbed of invaluable crown jewels (destined to be sold to finance England's armed forces) while on her way to Paris to ask her brother for assistance in the upcoming war. The Musketeers quickly discover the thief to be Émile Bonnaire, a flamboyant but pathetic criminal they have had history with in the past. Athos, Porthos and D'Artagnan pressure Bonnaire into leading them to the diamonds' buyers to recover them. Meanwhile, Aramis reconnects with Pauline, a childhood friend he grew up with in a bordel where their mothers lived and worked. She is set to marry a French nobleman but is being blackmailed by someone threatening to reveal the circumstances of her childhood, and Aramis tries to resolve the situation peacefully.
Set on the streets of 17th-century Paris where law and order is more an idea than reality, the series follows Musketeers Athos, Aramis and Porthos who are far more than King Louis XIII's personal bodyguards, but ultimately stand resolutely for social justice: for honour, for valour, for love and for the thrill of it.
The Musketeers - The Queen's Diamonds Synopsis and Schedule