The novel's perspective switches to Jack Will, who begins by remembering the call his parents got in August from Mr. Tushman, who asked if Jack would step up and help the new boy, August, feel welcome at school. Jack is initially opposed to reaching out in this way; he recalls seeing Auggie for the first time in front of a Carvel ice cream shop, when he and August were only five or six. Jack was immediately afraid of August's face, and Veronica -- the babysitter for Jack and his little brother Jamie -- rushed the two boys away quickly and scolded them.
Jack's mother continues to encourage Jack to help out, insisting that it is important to treat Auggie fairly despite how he looks. Finally, Jack agrees. He realizes that while there will always be kids who are jerks in general, even generally nice kids such as Jamie can be mean to people like Auggie -- which means that Auggie does not stand a chance in middle school.
Jack begins to hang out with Auggie, remarking that he got used to Auggie's face and that Auggie is actually a pretty funny kid. Eventually, Jack realizes that he actually does want to be friends with Auggie of his own accord. When Auggie suddenly gets angry and stops talking to him, Jack is extremely confused: he cannot figure out Summer's "Bleeding Scream" hint.
The first snow of the winter comes right before Thanksgiving, so Beecher Prep closes early and Jack's Dad takes him and Jamie sledding. Jack finds a banged-up wooden sled and takes it home to fix it up so that he can use it: the sled ends up being fun and fast. When Jack gets back to school after the break, he wants to tell Auggie about his sled, but he decides not to because the situation between the former friends is still tense.
Jack uses the next chapter to give a run-down of his family background. Even though Jack goes to private school, his family is not rich. The Wills live in a part of North River Heights where people don't usually want to go. Such circumstances make it strange for Jack to interact with some of his wealthier peers, like Julian, who does not seem to appreciate the advantages he has. While talking to Julian, Henry, and Miles one day, Jack starts to tell the other boys about his new sled; however, when Miles mentions leaving an old piece of junk sled at the hill, Jack realizes that this sled was the one that he took.
During a science class, Jack abruptly realizes what Summer meant by "bleeding scream." He realizes that Auggie overheard his cruel remarks while he was talking to Julian on Halloween. Jack feels terrible. Things only get worse when the science teacher, Ms. Rubin, pairs Jack and Auggie together for a science project. Julian starts to torment Jack about the pairing, saying that he could switch partners and that he does not have to be friends with "that freak." As soon as Julian utters these words, Jack punches him right in the mouth.
Jack gets sent to Mr. Tushman's office and his mother comes in to make sense of the situation. Both Mr. Tushman and Mrs. Will say that it is not like Jack to do something so aggressive, and Mr. Tushman wants to know why Jack punched Julian. Jack refuses to tell, since telling would cause a snowball effect, enabling everyone to figure out what happened between him and August. Mr. Tushman asks Jack to stay home for the rest of the week before winter break; then, Jack can come back from break with a clean slate. When he goes home, he notices that his family has received a holiday card from Auggie's family. At last, he tells his mother everything.
The next chapter consists of apology letters sent back and forth: the writers are Jack, Mr. Tushman, and Julian's mother Melissa. Julian's mother writes to Mr. Tushman, saying that she thinks it was wrong for Beecher Prep to allow someone like August to attend. The chapter ends with text messages between Jack and Auggie, which enable the two boys to finally make up and become friends again.
When Jack goes back to school after break, he realizes he has his own form of the Plague now. Only the girls will talk to him; few of the guys will. Charlotte gives him the scoop on what is going on: Julian is trying to turn everyone against Jack so that Jack will stop being friends with Auggie. There is a lot of drama in the lunch room over who (if anyone) will sit with Jack. Finally, Jack goes to sit with Auggie and Summer. Jack makes a comment about how it is weird to have people avoid you and pretend that you do not exist, and Auggie smiles and says welcome to his world.
Summer passes on a list of the sides that the guys in their class are taking in the "war" against Jack. Charlotte made the list, and Summer thinks that Charlotte did so because she likes Jack. Nonetheless, Jack says that he will not ask her out, and Summer agrees that the students in her grade are too young to be dating. Jack goes to Auggie's house for the first time to work on their science project. While they are there, Via brings her new boyfriend, Justin, home to meet Auggie.
This section is very important, because it at last gives readers Jack's side of the story. Since the end of the novel's first section, Jack has been painted as a villain. Via's and Summer's sections have also featured strong responses to what happened between Jack and Auggie: both Via and Summer are extremely upset about what has happened. But like any complex character, Jack has his own story, and in this section we learn that he may not be as mean as he appears to be.
Jack makes a very significant point early on in the section: it is not only "jerk" kids like Julian who are mean to Auggie and hurt his feelings, but also kids who would normally be considered "nice." Even nice kids do not realize how hurtful the things they say and the ways they behave around Auggie can be. Because of this harsh reality Jack realizes that it is important for him to do as Mr. Tushman asks and be a friend to Auggie. Middle school is a challenging place, especially for someone who looks different.
Palacio adds another dimension to this story by introducing, through Jack, some socioeconomic tension. Even apart from the usual challenges of middle school -- friendship, budding romances, and rumors -- Jack also has to deal with the uncomfortable reality that some kids, including Julian, come from families that are far better off financially than his own is. The events surrounding the sled offer an example of how Jack's status sets him apart from his classmates, even though he handles the insulting remarks about the sled with as much grace as he can.
Jack's punching Julian is a pivotal moment. This action proves Jack's allegiance at last, after Jack spends weeks struggling to figure out what has happened with Auggie -- and whether he cares more about being popular or being a good friend. Though it is hard for him to make up for what he said about Auggie, by punching Julian and thus defending Auggie's worth, Jack shows that he is desperate to do better.
The middle of this section introduces an interesting format: letters and texts, instead of regular narrative. These messages allow readers to gain insight into the minds of characters, like Mr. Tushman and Julian's mother, who might not be significant enough to get their own sections. Palacio's new format also brings the parents into the situation. Until now, Wonder has been primarily about the way Auggie's peers treat him. With Mrs. Albans's first letter, however, the parents start to get involved, as Mrs. Albans criticizes Beecher Prep for allowing Auggie to enroll. Now, the conflict has become even larger.
The "war" starting in the middle school over Jack's friendship with Auggie is a great example of the way school can be a microcosm of the hostile real world. Yet matters that would seem trivial in the world outside -- like who is friends with whom -- can be blown out of proportion in a middle school setting. Now that Jack finds himself in the middle of this war, he will have to handle himself carefully if he hopes to come out with the friends he truly wants.