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 and where to go. Who might Baby meet as she strikes out on her own, and what could she discover about herself? Will her impulsive adventure take her away from Eugenia for good?