August Pullman has been homeschooled due to some complicated health issues related to a dramatic cranio-facial abnormality and the rigorous surgery schedule that comes with it. But by the time August turns ten, his parents are beginning to think about the big picture a.k.a. long-term. They have realized that Auggie not only needs to learn more than his mom can teach him, but he also needs to learn to navigate a world that isn't always kind to those who are different.
Enter: middle school.
At Beecher Prep in Manhattan, fifth grade is the first year of middle school, so it's a good time for August to plunge into the mainstream. At first Auggie dreads the idea of so many kids staring at him. And who can blame him? But when his mom tells him about the chicks (no, not the beautiful ten-year-old babes—the actual chickens that hatch in the science classroom incubator), he's kind of psyched.
Mr. Tushman, the principal of Beecher Prep (and the butt of many a weak joke), arranges a small welcome committee for August. He asks three kids he has heard are really nice to befriend Auggie, show him around, and help him transition into school life. Charlotte is polite and pleasant, Jack is reserved but nice, and Julian is an unkind creep pretty much from the get-go. Oh good.
The welcome wagon being an imperfect entity, Auggie finds himself sitting alone at lunch the first day of school. Out of the blue though, a really nice girl named Summer sits down and strikes up conversation. She first sits with him because she feels sorry for him, but it doesn't take long for the two kids to become friends. Outside of lunch, Jack's desk is next to Auggie's in almost every class. And once he gets used to Auggie's face, Jack realizes that Auggie is a cool, smart, fun kid, plus a really good friend. So while he's not exactly Mr. Popular, Auggie has made a couple of solid friends.
But Jack lacks self-confidence and the courage to stick with his convictions, and finds himself badmouthing Auggie with the best of 'em. Except he doesn't realize that Auggie is sitting at the next desk over, wearing a Halloween mask. It's a devastating betrayal, one that sends Auggie bolting for the bathroom in tears and swearing never to return to school. Luckily his big sister, Via, prods him into returning, saying that learning to cope with the awful days is part of growing up and facing life. Plus she threatens to rat him out. She's still his sister, after all.
Auggie goes back to school, but drops Jack like the proverbial hot potato, leaving his former friend hurt and bewildered. Of course Jack eventually figures out where things went off the rails, and when he does, he feels like a super jerk—and shortly thereafter a showdown between Jack and mean-kid Julian ends up with somebody missing a baby tooth.
Jack and August make up and it seems like life is getting back on track… at least until Jack returns from winter break and finds himself suddenly a total social reject. Julian has turned the entire class against Jack for his decision to remain friends with Auggie "The Freak" Pullman. Jack's loyalty is truly put to the test now, as he suffers social isolation on par with Auggie's. If he ditches Auggie, he gets to hang with the popular crowd—but Auggie and Summer are pretty much the only kids still speaking to him, giving him support even though he's let Auggie down in the past.
The climax of the story comes when the fifth graders are away at nature camp. Auggie and Jack are accosted in the woods one night by some big seventh-graders looking for trouble, and Auggie is verbally and physically assaulted for no reason other than his appearance. A few other boys from Auggie's class circle back to see what's going on, but when they step in to help, the situation explodes into a scuffle. Sweatshirts are ripped, elbows get scraped, and most painfully, Auggie's expensive hearing aids are lost in the night.
Auggie is terrified and hurt, but exhilarated too. Even in pain and in tears, he realizes that boys who have until this point either actively shunned or passively ignored him have, on this occasion, stood up for him and protected him, and have pledged to continue to do so. The injustice of the cruelty toward August catalyzes a permanent change for the better in his classmates' attitudes.
This turning point signals the end of Auggie's painful isolation. His peers finally accept him as one of their own—as a kid with a heart, a brain, and a great sense of humor in addition to his weird face. Auggie's fifth grade year culminates in victory, and he is admired by students and teachers alike for his courage, his perseverance in the face of difficulty, and the quiet strength of his character.