It's Halloween and Claude and Claudette are reading ghost stories when they hear a mysterious tapping sound on the wind. Deciding that it must be the sad ballerina ghost from one of their stories, they set out in the middle of the night to help her... and unwittingly stumble across two weasels robbing Pamplemousse's mansion! Luckily Anatole arrives on the scene, and with Gaston's help turns the thieves over to the authorities. The children have learned not to let their imaginations run away with them, and are surprised to find out what the real source of that tapping sound is!