Mirabelle's mum is a witch, her dad is a fairy, and she is a bit of both! Mirabelle and her class are going on a school trip to a magical-creature sanctuary, and Mirabelle can't wait! Even being partnered with annoying goody-two-shoes Lavinia can't ruin her day. But when she accidentally lets the bittens (part bat, part kitten, totally adorable, slightly fierce) out of their enclosure their day becomes a bit more complicated. Can Lavinia help Mirabelle stay out of trouble? And can Mirabelle show Lavinia that maybe some things are worth getting in trouble for. . . ?