When Dad and Daddy adopt a new baby, Harper is excited to be a big sister for the first time. She picks out a stuffed animal just for her baby brother and practices holding a doll in case Dad and Daddy's arms get tired. She can't wait for the new baby to join all the family's favorite activities! But when the new baby arrives, Dad and Daddy don't have as much time or energy as they used to.

Everything is about the new baby! Daddy is too tired from being up all night with him to play hide and seek with Harper. Dad is too busy taking care of the baby to go to the park. Even Taco Tuesday is ruined!