After an unsqueakably fun summer at camp, Humphrey can't wait to get back to Room 26 and see his classmates. But something fur-raising happens on the first day of school -- some kids he's never seen before come into Mrs. Brisbane's room. While Humphrey gets to know the students, he wonders about his old friends. Where could they be? It's a big mystery for a small hamster to solve.

"It is Princess Harriet Hamsterbone to the rescue when Heady the hydra's egg is stolen, but her search leads her to a castle accessible only by a rat with a very long tail"--

After learning about Sherlock Holmes, Humphrey the classroom hamster follows clues to try to 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.

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.

"Harriet Hamsterbone sets out to reverse the curse on twelve mice princesses who are forced to dance all night, every night"--

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.

A little girl in a red cape asks for Princess Harriet Hamsterbone's help with a pack of weasel-wolves who want to eat her grandmother, but after meeting everyone, Harriet is not sure whom to trust.

Climbing to the top of a towering beanstalk that has grown from a magic bean, Harriet Hamsterbone finds a castle inhabited by a giant who is holding two unusual prisoners.

Disappointed that the new class pet is just a hamster, Polly uses her magic book, Spell, to conjure up a more interesting pet--and than has to figure out how to resolve the resulting topsy turvy chaos.

When second-grader Eugene and his family move to a new neighborhood and he starts at a new school, he has a chance to bring out his superhero alter ego, Captain Awesome, to find the kidnapped class hamster.