Aramis saves young widow Agnès Bernard from being killed by ruffians, who steal her baby Henri, whose father, the deformed Philippe was murdered by ignorant villagers who thought he was an agent of the devil. Helped by Constance, the Musketeers retrieve the baby. At the same time Marie De Medici, the king's mother whom he banished after she tried to oust him from the throne, appears, claiming her life is in danger but neither she nor her guard captain and lover Vincent are convincing. Agnès recognizes Marie as being Philippe's mother and indeed she is, hoping through her son, the baby Henri, making another claim to the throne. The Musketeers have to get Agnès and her child to safety as well as thwarting Marie, and this time Richelieu is on their side.
—don @ minifie-1