Babymouse's art class is headed to a museum in the Big City. And now that they're middle schoolers, she and her friends will be totally unsupervised! She can't wait to check out all the world-famous art...that is, until she overhears Felicia Furrypaws planning to ditch the museum and hit the town instead. Babymouse decides to test her freedom with an urban adventure of her own. Will she make it back to the museum before the bus leaves? Or will life in the Big City trip her up big-time?