After the death of Richelieu the musketeers rescue one of his spies, Rochefort, from a lynch mob and take him to see the king. He explains that he has escaped from a Spanish jail but that the French general De Foix and his sister are still prisoners and asks that the musketeers help him free them. The mission is accomplished and Rochefort is appointed as Richelieu's successor - but can he be trusted? Meanwhile Queen Anne, having recently given birth to a son, appoints Constance as her confidante.