In medieval France, Jerry and Tuffy find the King being held prisoner by the evil Baron of Larue [Tom]. They defeat the "poossycat" and free the King.; The King wants to send the Two Mouseketeers to slay a dragon. M'Sieur Poossycat tries to keep the Mouseketeers from going on the mission, so that he can slay the dragon and collect the reward.; When M'sieur Poossycat tosses the Mouseketeers from the castle, they go to a neighboring castle, where they learn magic from a sorcerer.; The Mousetekeers keep M'sieur Poossycat from delivering plans for the castle's defense to an enemy agent.; The Mousketeers use their secret weapon, a chunk of limberger cheese to foil M'sieur Poossycat.; The Mouseketeers take advantage of a friendly dragon's flame to roast hot dogs.; The Mouseketeers use can-openers as a defense when M'sieur Poossycat attacks them in a suit of armor.