After Humphrey's fur-raising holiday, he was looking forward to returning to Room 26. Mrs. Brisbane is still there, but Humphrey is shocked to find that the classroom is filled with strangers, like Rolling Rosie, Hurry-Up-Harry and Forgetful Phoebe. At first, all Humphrey wants to do is find his old classmates but he soon learns that these new students really-really-really need a helping paw.