Spring has sprung, and everyone at Longfellow School, including Ms. Brisbane's class, is happy-happy-happy! Family Fun Night is coming up, and all the students' families are involved in making amazing circus activities. Humphrey helps in many ways, but he can't help but wonder about his own family. He doesn't know anything about them. But when he thinks about all of the wonderful friends he has made at school and at his friends' homes, he stops worrying. Just as spring comes every year, with lots of new things that grow and change, Humphrey's family of classmates and friends will always be growing. And that's just how this adorable little classroom pet likes it.