Lily and Imogen's class assignment to protect an enchanted mailbox goes wrong and a postman is transformed into a dog; Kyra must use her magical ability to talk to dogs to find the missing pooch before the change becomes permanent.

While under the scrutiny of crack DMI Agent Orla, Kyra and her class members are tested on their ability to handle magical outbreaks; when Orla releases a magical force that endangers Peter, Kyra must choose between the two worlds she now inhabits.