Der Kardinal schmiedet wieder Ränke: Er schickt Mylady de Winter nach London, um sich die Halskette der Königin, das Freundschaftspfand, anzueignen. Dann arrangiert er einen Ball, auf dem die Königin die Diamanten tragen soll. D’Artagnan und die drei Musketiere werden von Juliette, der Kammerzofe der Königin, eilig nach London abgesandt, um das kostbare Stück zum Ball zurückzuholen.
Dogtanian and Pip are indulging in a little horseplay when they run into a beautiful lady. She turns out to be none other than Milady, and tricks Dogtanian into losing his nice new dagger. He manages to snatch it back and he and the Three Muskehounds pursue Milady on horseback, but she gets away. Richelieu, meanwhile, has a cunning plan to disgrace the Queen by persuading the King to hold a ball at which his wife should wear her diamond studs, now in England in Buckingham's possession. He dispatches Milady to London to get the jewels. Juliette begs Dogtanian to travel to England and retrieve the diamonds in time for the ball. He seeks permission from Treville, who agrees on condition that the Three Muskehounds accompany him.
Alors que d’Artagnan fait miroiter sa nouvelle dague pour impressionner Pomme, Milady la lui vole. Ses amis découvrent qu’elle fait partie des hommes de main de Richelieu. Une nouvelle mission l’attend...
Quando Dartacão mostra a Pom o seu novo punhal, Milady apodera-se dele. Os seus amigos ficam a saber que ela é um dos agentes de Richeleão. Richeleão envia Milady a Londres para roubar o colar da rainha e provocar um escândalo no baile que terá lugar em Paris quando a rainha não o usar. Dartacão e os Três Moscãoteiros põem-se imediatamente a caminho rumo a Londres.
