Mysteries According to Humphrey

This children's novel is narrated by Humphrey, a classroom hamster who serves as the pet in Room 26 at Longfellow School. Humphrey is unusually intelligent: He has secretly taught himself to read and write, keeps a hidden notebook behind the mirror in his cage, and can open his cage door using a lock-that-doesn't-lock, a latch that humans believe is secure but that Humphrey has learned to wiggle open. He shares the classroom with Og, a frog who lives in a tank beside his cage and who remains something of a mystery to Humphrey, since frogs behave very differently from hamsters.

It is October, and Mrs. Brisbane, the class teacher, has been reading aloud from a Sherlock Holmes story, "The Adventure of the Red-Headed League." She stops before the ending and teaches the students how to figure out unfamiliar words using context clues. Humphrey has given each student a descriptive nickname based on their habits, including Hurry-Up-Harry for a boy who is chronically late, Forgetful-Phoebe for a girl who constantly misplaces things, and Thomas T. True for a boy who tells exaggerated stories. At the end of the day, Mrs. Brisbane tells Humphrey and Og she will see them in the morning, a detail that becomes significant the next day when she fails to appear.

The following morning, the classroom door stays locked. Mr. Morales, the school principal, eventually lets the students in and explains they are trying to reach Mrs. Brisbane. A phone call confirms she will not be coming, and a substitute is dispatched: a young, red-haired man named Ed Edonopolous who tells the students to call him Mr. E., which sounds like "mystery." Rather than following Mrs. Brisbane's detailed lesson plans, Mr. E. fills the day with games. Mrs. Wright, the physical education teacher who enforces school rules and carries a loud silver whistle, reprimands him for the noise. Ms. Mac, whose full name is Morgan McNamara and who is the first-grade teacher who originally brought Humphrey to Room 26, visits during lunch to show Mr. E. where Mrs. Brisbane keeps her lesson plans and mentions that Mrs. Brisbane may be out for a while.

That night, Humphrey begins collecting clues in his notebook: Mrs. Brisbane's absence was unplanned, Mr. Morales was caught off guard, and Aldo, the school custodian who cleans Room 26 each evening, seems worried. Humphrey escapes his cage and tries to open the Sherlock Holmes book on Mrs. Brisbane's desk, hoping to learn detective methods, but the book is too heavy for him.

Mr. E.'s second day brings more games. During Word War, a game in which students race to the board to add letters to a word, classmates Simon and Kelsey Kirkpatrick collide. Simon gets a bump on his head, and Kelsey gets a black eye. Mr. Morales reads a note from Mrs. Brisbane: She says she misses everyone, that she will be "up on my feet and dancing before long," and that "this all came about because of Humphrey" (50). Humphrey is alarmed, believing he somehow caused her absence, and her references to dancing lead him to theorize she has left to study ballet.

Kelsey takes Humphrey home for the weekend. Her brother calls her "Clumsy," reinforcing her self-doubt before her first ballet lesson. While the family is out, Humphrey opens a music box and teaches himself to twirl. When Kelsey returns, Humphrey dances in his cage, and Simon teaches Kelsey a trick for spinning without stumbling. Kelsey attends her first ballet class and returns enthusiastic, reporting that her teacher said she can be graceful if she pays attention to what she is doing.

Back at school, another note from Mrs. Brisbane mentions she has put on her slippers, which Humphrey interprets as ballet slippers. Mr. E. has the class make get-well cards, but the activity turns chaotic. Mrs. Wright blows her whistle to restore order and delivers Harry, whom she found wandering the halls during class. Without Mrs. Brisbane's structure, Harry has reverted to his habit of chronic lateness. That night, Humphrey reads through the cards and writes his own small poem for Mrs. Brisbane, decorating it with strawberry-juice paw prints and having Og splash water drops onto it as Og's mark.

During free time, Phoebe confides in Humphrey that she has lost her daisy watch, a gift from her parents, who are both deployed in the military. She lives with her grandmother and explains that she thinks about her parents so much she forgets everything else. Mrs. Brisbane used to send reminders home, but Mr. E. does not. That night, Humphrey escapes his cage, travels through the dark hallways, squeezes under the gymnasium doors, and searches the lost and found in Mrs. Wright's office. He finds the watch, a gold-banded watch with a smiling yellow flower on its face, and a flyer for the Military Kids Club (MKC), a new program for students with parents in the military. Wearing the watch around his middle, he makes the journey back to Room 26 and leaves both items in front of his cage.

The next morning, Humphrey performs tricks to draw attention. Kelsey spots the watch and the flyer, and Phoebe reclaims them. Meanwhile, Humphrey observes that classmate Joey repeatedly rebuffs Thomas's attempts at friendship. After school, Mr. Morales meets privately with Mr. E. and lists complaints: safety issues, parents concerned about a lack of homework, and a district-wide math test approaching with students unprepared. He gives Mr. E. another chance. Mr. E. confides in Ms. Mac that his first substitute assignment at a different school was traumatic: Students threw paper wads at him, which led him to prioritize fun over learning. Ms. Mac takes Mr. E. to visit Mrs. Brisbane that evening for guidance.

The next day, Mr. E. transforms. He follows Mrs. Brisbane's lesson plans, teaches real lessons, and assigns genuine homework. The students respond well. For the weekend, he arranges for Humphrey to stay with both Thomas and Joey. At Thomas's house, Humphrey deliberately rolls his hamster ball under the couch so the boys must search together. Joey confronts Thomas about his exaggerating, telling him he is lucky to have a dad around, since Joey's own father lives far away. Thomas admits most of his stories are embellished, and Joey tells him to just be himself. The two bond and study for the math test together. On Monday, the class performs well on the test. Mr. E. also talks to Harry about punctuality, resolving his lateness. Phoebe attends an MKC meeting and begins remembering her homework. As promised, Mr. E. reads the conclusion of the Sherlock Holmes story.

On Halloween, the students wear costumes. Thomas and Joey dress as Sherlock Holmes with deerstalker hats and magnifying glasses, Kelsey is a ballerina, Phoebe wears a camouflage military uniform, and Rosie, a classmate who uses a wheelchair, creates an elaborate "head on a plate" costume. Humphrey fashions his own costume from red yarn to resemble a redhead from "The Red-Headed League." A pumpkin-headed skeleton and a hideous witch enter the classroom. The witch removes her mask to reveal Mrs. Brisbane, and the skeleton is Mr. E.; they planned the surprise together after he visited her during her recovery.

Mrs. Brisbane explains the truth: She was running late for school and went back inside to get Humphrey's vegetable treat. Her heel caught on the front step, she fell and broke her ankle, and could not reach her phone. Her references to "slippers," "dancing," and "performing" described her physical therapy and rehabilitation, not ballet, demonstrating that clues can lead a detective in the wrong direction. Humphrey and Rosie tie for Best Costume, and Mr. E. receives a gold ribbon for Best Substitute. Mr. Morales announces that Mrs. Brisbane will return the following week and recommends Mr. E. as a substitute for another classroom. Humphrey reflects happily that his favorite teacher is coming back and that as a hamster living among humans, he will always have mysteries to solve.