Lilly is a mouse with headstrong and loud personality and a tendency to proclaim herself as” Queen of the World.” She struggles with her friendships, fearlessly defends the weak from bullies, and is seems unstoppable—until a baby brother comes along that threatens her happiness. When her Grandma buys Lilly a new purple plastic purse that plays music (as well as a stunning new set of movie-star sunglasses and throws in three shiny quarters), Lilly’s life turns around. But when a lot of attitude causes her to get in trouble at school, and her beloved teacher Mr. Slinger confiscates her new things, Lilly has a very bad day. She learns that difficult days can happen, but that tomorrows can be better too.