Waiting is hard. Liam waited through half of kindergarten for his baby sister to be born. Then, when little Sophie finally comes home, he discovers she won’t be ready to play with him for a long, long time. As the months pass, everyone says that Liam is Sophie’s favorite. He is the best at making her laugh and burp, but laughing and burping are not enough for Liam. With the help of Nana-Downstairs, he designs and builds a Get Older Faster Machine. It doesn’t seem to work on Sophie, but maybe Sophie is not the only one doing some growing up.