Baby Lincoln's older sister, Eugenia, is very fond of telling Baby what to do, and Baby usually responds by saying, "Yes, Sister." But one day, Baby has had enough. She decides to depart on a Necessary Journey, even though she has never gone anywhere without Eugenia telling her what to take with her and where to go. Can Baby find the courage to strike out on her own and discover who she really is? And will her impulsive adventure take her away from Eugenia for good?