The Secret of Cacklefur Castle by Geronimo Stilton

Moldy mozzarella, it was every mouse's worst nightmare! My old friend Creepella von Cacklefur called me one night and ordered me to join her for the weekend at her family's spooky castle. And before I could say "boo!" she'd mouse-napped me! Now I was stuck in the gloomiest, eeriest castle I'd ever seen. Even worse, I was surrounded by Creepella's creepy family! Oh, would I ever escape back to my safe, cozy mouse hole in New Mouse City?