When Humphrey the hamster returns to Mrs. Brisbane's class after the winter break, a new class pet and some other surprises give him an opportunity to reflect on the meaning of friendship.

While continuing to help his classmates solve their problems, Humphrey, pet hamster of Longfellow School's Room 26, faces many surprises, like rolling in a hamster ball, a substitute janitor who might be an alien, and the possibility of Mrs. Brisbane retiring.

When summer arrives, Humphrey, the pet hamster of Longfellow School's Room 26, is surprised and pleased to learn that he will be going to Camp Happy Hollow.

After learning about Sherlock Holmes, Humphrey the classroom hamster follows clues to try and discover why Mrs. Brisbane is gone and Mr. E, a fun but not very educational substitute, is taking her place in Room 26 at Longfellow School.

Humphrey, the pet hamster of Longfellow School's Room 26, learns that his classroom is full of secrets, the most important of which is that a student will be leaving soon.

"To Humphrey and the students at Longfellow School, spring seems impossibly late this year. Fortunately, planning a school Family Fun Night keeps the students (and classroom pets) busy as they look for signs of the changing seasons"--