Maggie has discovered a kobold—a creature similar to a house brownie but with an evil bent. Her grandfather trapped a particular kobold thirty years ago to keep it away from Maggie's father, but the creature has escaped and is out to punish Maggie's family. Narrowly escaping the creature in her house, Maggie and Hasenpfeffer head to Mr. McGuire's Magic Repair Shop to repair the spell and end up in a tricky spot thanks to Milo the Magnificent. Milo may still be trapped in the magice mirror, but he's trying to get out, and in the kobold he may have found someone to help him—even if that includes kidnapping Fiona and Mr. McGuire! Can Maggie foil Milo's plans, stop the kobold, rescue her friends, and escape the mirror maze? Or will she be stuck inside forever?