Paris, 1975. Something incredible happens: Magalie the mouse disappears without a trace! And so do all the other mice in the neighbourhood. Charloc, who is (almost) not afraid of anything, desperately sets out to find her. But the cat immediately realises that he needs friendly help. The feathered and four-legged neighbours happily join the adventure. I swear by Charloc's moustache, it's going to be a great investigation!