The Musketeers arrive at the prison to try and avert disaster on the streets.
The musketeers battle to restore order in Paris after Grimaud and Feron stage an ambitious Chatelet breakout, setting free a lunatic with murderous designs on the Louvre. Using one prisoner's unlikely talents to rob the royal vault, the plotters prepare to make their first move against the king. But ailing Feron is distracted, and his ruthless silencing of an unwelcome visitor could be Grimaud's undoing. Ambitions collide during the Dauphin's birthday party, where a kind act by d'Artagnan pushes lovers together and ends in catastrophe.