Goodbye, Mr. Terupt

The fourth and final installment in the Mr. Terupt series follows seven friends through their eighth-grade year as they face the prospect of losing the teacher who changed their lives. Narrated in rotating first-person chapters, the story traces the group's efforts to create lasting memories before an inevitable goodbye.

The story opens during summer as Peter, the group's self-described prankster, introduces the "gang": himself; his on-again-off-again girlfriend, Lexie; aspiring writer Jessica; farm girl Danielle, who manages Type 1 diabetes; Danielle's best friend and soon-to-be stepsister, Anna; science enthusiast Luke; and wrestler Jeffrey. At the Summer Sound Festival on Long Island Sound, the friends encounter their beloved teacher, Mr. Terupt, with his wife, Sara, and baby daughter, Hope. When the Terupts mention needing a babysitter, the friends eagerly volunteer, forming what Peter dubs "the Babysitters Gang."

At a tense family dinner, Danielle's brother Charlie announces he will marry Terri, Anna's mother, on the farm in October. Meanwhile, Danielle switches from daily insulin injections to an insulin pump. Anna quietly struggles with jealousy as Terri's relationship with Charlie consumes the mother-daughter time they once shared, but she keeps these feelings buried.

Jeffrey and Peter attend wrestling camp at Cornell, where Jeffrey privately sets a goal of going undefeated. During the gang's first babysitting session, Peter unknowingly drinks stored breast milk he mistakes for a smoothie, and Lexie leverages the humiliating secret to control him. A television commercial for GeneLink, a home DNA testing kit, catches Lexie's attention. Given her mother's history with breast cancer, she begins worrying whether she carries the gene.

When school starts, a new biweekly advising period places the gang in Mr. Terupt's group, even though none of them have him as a classroom teacher. Mr. Terupt proposes a time capsule project, with each member contributing a secret item to open at year's end. Jeffrey begins attending open mats, optional after-school wrestling practices, at the high school under Mr. Terupt's guidance. An older wrestler named Freddy suggests Jeffrey could compete at 113 pounds if he cuts weight, planting a dangerous seed.

At Charlie and Terri's October wedding, the infusion set connecting Danielle's insulin pump to her body rips off during the wagon ride to the ceremony. Not wanting to ruin the day, she stays silent. Without insulin, her blood sugar skyrockets. Anna finds Danielle collapsed and sprints for insulin and needles. Danielle is rushed to the emergency room and diagnosed with diabetic ketoacidosis, a dangerous condition caused by prolonged high blood sugar. Anna pledges to carry backup supplies for Danielle going forward.

Meanwhile, Lexie steals a GeneLink kit from a store and, during a babysitting session, collects her saliva sample and mails it, making the girls promise she will not open the results alone. Jessica's father, Jack Writeman, moves to the area unexpectedly, though Jessica remains guarded given his history of broken promises.

In November, Jeffrey secretly begins restricting food to reach 113 pounds for a varsity wrestling spot. His mood deteriorates and his performance drops. At a home meet, he barely defeats an opponent on a last-second reversal. Afterward, irritable and searching for excuses, he breaks up with Anna, claiming she is a distraction. Anna is heartbroken, and her isolation deepens as she notices Danielle spending more time with Luke, who visits the farm regularly for a biology project studying calf growth.

Jeffrey's crisis peaks when Peter pins him at practice. Jeffrey shoves Peter and storms off. Mr. Terupt follows, gets Jeffrey to confess, and reveals that Freddy has already quit the sport from excessive weight loss. Mr. Terupt tells Jeffrey his natural weight class is 120 and Peter belongs at 113. Both boys will move to varsity together after the holiday tournament, where Jeffrey dominates his rematch opponent and wins Most Outstanding Wrestler.

Danielle arrives at the tournament bearing devastating news: She saw a For Sale sign on Mr. Terupt's lawn. Mr. Terupt confirms he and Sara are moving to be closer to her family. Peter feels the deepest betrayal, viewing the move as abandonment, and refuses all contact with Mr. Terupt. Jeffrey confronts Peter, drawing on his own grief over his brother's death to argue that quitting only makes things worse. Peter walks away but shows up at varsity practice the next day.

Luke proposes a bucket-list project, a series of meaningful events to celebrate their remaining time with Mr. Terupt. The first is a Polar Plunge into the freezing Long Island Sound to raise money for juvenile diabetes. Peter initially refuses but relents after witnessing Danielle's daily struggle with her insulin pump, and the event begins healing the group.

Jessica proposes the second event, a head-shaving fundraiser for breast cancer awareness in honor of Lexie's mother. On the day of the event, the boys shave first to steady Lexie's nerves. The four girls have their hair cut for donation, then buzzed. When a heckler insults them, Danielle's grandmother, Grandma Roberts, climbs the bleachers and silences him, earning a standing ovation. The pivotal moment comes when Mr. Terupt's shaving reveals the scar from a snowball injury Peter accidentally caused years earlier. The sight cracks Peter's emotional armor; he runs across the gym and embraces Mr. Terupt, finally reconciling.

Jeffrey's bucket-list idea is Wrestle'Lympics, a wrestling event pairing team members with students who have special needs, echoing the gang's earliest work with Mr. Terupt. Mr. Terupt then selects Jessica's event: a poetry slam. Jessica writes a poem called "The One," and Lexie performs it as their joint persona, "the Poet Jexia." Jeffrey and Peter surprise everyone with original poems. As the slam concludes, Mrs. Terupt goes into labor with their second child.

During the final advising session, Luke reveals his bucket-list event: a dice-and-card game generating random future dates, which become nonnegotiable reunion commitments for all seven friends and Mr. Terupt. The dates span decades, transforming goodbye into "see you later." The gang also opens their time capsule, sharing laughs over each contribution.

Several personal threads resolve in the closing chapters. Anna finally confesses her jealousy to Terri, who promises better communication and reveals she is pregnant. Jessica visits Lexie's mother, Miss Johnson, at her workplace and tells her about the GeneLink test. Miss Johnson opens the results and discovers Lexie does not carry the cancer gene variants. Relieved, Lexie returns to the store and pays for the kit she stole. Jeffrey's toddler brother, Asher, pushes Jeffrey's and Anna's hands together at the farewell gathering, prompting their reconciliation and first kiss. Luke and Danielle's quiet romance also begins to bloom.

The gang gathers at the Roberts farm for a farewell dinner, exchanging silent hugs before watching the Terupt family drive away. Jessica reveals through a poem that her father has bought Mr. Terupt's house and her mother has agreed to try again as a family. In the epilogue, Mr. Terupt narrates as he and Sara discover hidden artifacts the gang planted in their moving boxes: drawings, photographs, poems, a scarf, woodwork, and Peter's gift-wrapped box containing a note claiming he trapped a fart inside. Sara asks if Mr. Terupt is sure he will miss Peter. He replies that he already does.