When time goes backwards, granting six-year-old Otto his wish that his attention-stealing baby sister was never born, it keeps going backwards, and Otto finds himself getting younger and younger.
Davy, formerly the youngest in the Rabbit family, is not happy about the arrival of a new baby, but he is surprised at what happens when he holds her for the first time.
Jo-Jo wishes she were small like her new baby sister Roo until Dad says Jo-Jo is big enough to have a birthday party with invited guests, jumping games, and hidden presents.
No one understands what Molly wants when she starts to cry, but when she struggles to take her first steps, two older brothers realize what she's after.