The Muscleteers are in Paris! In Monsieur Albert’s cargo ship, hidden among 700 Camemberts, Picandou, Gruyère, Pomme de Terre and the hamster Bertram have travelled to France in an entirely unplanned cloak-and-dagger operation. But there’s little time for sightseeing, because Filou, Monsieur Albert’s house mouse and all-round guardian angel needs their help: Albert’s Camembert factory is facing ruin! A cheapo-cheesemaker has set his sights on Albert’s ancient secret recipe and is planning a horrible act of sabotage that will sink Albert’s business. Not only that, but the four heroes have to keep a mysterious rat queen and a greedy monster of a tom cat in check. Will their mission succeed? And will the Mousketeers ever see their home town of Hamburg again? Another amazing adventure, as only Ute Krause can deliver!