Mirabelle is having a sleepover at her best friend Carlotta's house, and the pair have been told they are absolutely not allowed to go in big sister Edith's bedroom. Surely a little look can't hurt, so they decide to sneak in when Edith goes out. But while exploring, they accidentally break one of Edith's treasured possessions. Mirabelle and Carlotta are going to be in big trouble if Edith finds out. What are they going to do?