Mr. Wolf has just started teaching at Hazelwood Elementary. He wants the first day of school to go well, but he’s got his hands full with his new class. Some of his students include Margot, who is new in town and is trying to make friends; Sampson, who brought something special to school for show-and-tell; Aziza, who just wants everyone to be quiet, and do their work; and Penny, the girls who is very sleepy, because she has a new baby brother at home—who suddenly goes missing!