Artist, animal lover and would-be swimming sensation Mimi Power knows what it's like to live under the tyranny of a three-year-old sister. Things have never been the same in the Power house since "The Waby" arrived. Finding creative space in all the chaos is getting harder by the minute for Mimi. But with the school art show looming and a prize too-good-to-give-up-on at stake, Mimi comes up with a plan that's three-year-old foolproof. Or is it? To know for sure, Mimi will have to tap into her big sister power and find her own little piece of the sky.