The lunch club. 7 Night of the living rocks

Summary: Tia, Leo and Mr. Peabody face off against Madame Celeste and her minions in her secret underground lair, where she's been plotting -- naturally -- to take over the world. The Lunch Club heroes have a perfect plan: wait until midnight, then sneak in and rescue Mr. Fish, the guardian of the Pisces constellation. What they don't account for? Madame Celeste has a legion of living rock minions, who capture Mr. Peabody. The list of who Tia and Leo need to save keeps getting longer -- until it includes them too. Things take an even more desperate turn when Madame Celeste, in a misguided plan to win friends and influence people, attempts to control the guardian of the thirteenth sign of the zodiac. This thirteenth sign so powerful (and evil!) that it has been kept secret throughout history. This latest adventure has it all: the tragic origin story of Madame Celeste's fuzzy slippers; the problem of invisibility potions (what do you do when your body turns invisible, but your clothes do not?), and an even eviler new bad guy!