Hildegarde is no ordinary mouse; she's the Mouse Mistress of Saint Bartholomew's, and it's her job to keep all the other church mice safe. But her job is far from easy! First, there's a visit from the dreaded exterminators. And as if that weren't bad enough, St. Bartholomew's is holding a ceremony called the Blessing of the Animals — and that means the church will soon be filled with all kinds of pets...including cats! How can Hildegarde protect her scampering, squeaking tribe from the church's many dangers?