Arthur tells D.W how she acted when Kate was born, starting after Kate was brought home for the first time in "Arthur's Baby". D.W. is excited but frustrated when she does not get to help with Kate. Kate's crib is moved into D.W.'s room but D.W. soon finds drawbacks to sharing a room with a baby. D.W. soon becomes jealous over the attention Kate is getting. She tries to get rid of Kate. When that does not work, she runs away thinking the family doesn't need her.