Humphrey is excited to get back to Room 26 and see all his old classmates. But on the first day of school, a bunch of strange kids arrive, and no matter how loudly he squeaks up, they don't realize they're in the wrong room! Once Humphrey gets over the shock of being with a whole new group of students, he gets busy learning all about them and their problems. There's Rolling-Rosie, who can pop wheelies with her wheelchair; Tall-Paul and Small-Paul, who don't like to hear about their height; Hurry-Up-Harry, who loses track of time; and more. He hasn't forgotten about his friends from last year, and of course they miss him a ton. But when they start talking about taking him from Mrs. Brisbane's room, Humphrey gets unsqueakably nervous. How could he say good-bye to Mrs. Brisbane and Og for good?