After kissing Aunt Polly good-bye, Tom feels much better. On his way back to school, he sees Becky Thatcher and decides, on impulse, to apologize. He says that he has been mean, and he asks to be friends again. Becky shouts an insult and runs away. This makes Tom furious, and he wishes she were a boy so that he could beat her up. This being impossible, he settles on insulting her, and Becky’s hatred for him is confirmed before the lunch recess is over. She longs for the afternoon’s classes to begin so that she can see Tom whipped for ruining his spelling book.

The town’s teacher, Mr. Dobbins, has always wanted to be a doctor. However, he never had enough money to pursue a degree in medicine, so he has only managed to become a schoolmaster. Every day during the school hours, when the children are busy with their work, he takes a book out of a drawer and studies it. Every child in the school is dying to know what book it is, but they never get a chance to find out because he keeps it locked securely in his drawer.

Today Becky is in a sulk because of Tom’s latest insult, and so she is the first student to step into the classroom after lunch. She glances at Mr. Dobbins’s desk and sees the key waiting in the lock. She stares for a moment, glances around to make sure she is alone, and then takes out the book. The title is Anatomy, a word she does not know, so she opens it to the title page. There she sees a picture of a human being. As she studies it, Tom enters the room behind her. Surprised, Becky jumps and accidentally tears the picture. She shoves the book into Mr. Dobbins’s desk and whirls around to face Tom, shouting that he scared her on purpose to get her in trouble. She accuses him of wanting to tell on her to get her whipped.

Becky runs crying to her desk, and Tom stands still, shocked. He reflects that Becky is “a curious kind of fool,” and that it is typical of a girl to be “so thin-skinned and chicken-hearted” as to be scared of being whipped by a teacher. He has no desire to get her in trouble, but he knows that Mr. Dobbins will ask everyone in the class if they are responsible for tearing the book. Becky will surely give herself away: “Girls’ faces always tell on them. They ain’t got any backbone.”

When the afternoon’s classes begin, Tom sits brooding about Becky’s problem. He is still mad at her, but he cannot help feeling sorry that she is so upset. His messy spelling book is soon discovered, and he gets whipped for it. This does not upset him because he thinks he might have spilled the ink without noticing. He denies it, of course, “for form’s sake and because it [is] custom.” But as soon as the punishment is over, his mind returns to Becky’s predicament.

When Mr. Dobbins takes out his special book that afternoon, Tom wants to grab it and run—but he hesitates and misses his chance. When the teacher notices the torn page, he stands up and stares at the class, his face full of a quiet anger that fills “even the innocent with fear.” As Tom expected, Mr. Dobbins asks each student in turn if they tore the book. When he gets to Becky, she cannot look him in the eye. Before she can stammer out her answer, Tom leaps to his feet and shouts, “I done it!”

Tom’s heart lifts when he sees “the surprise, the gratitude, the adoration” in Becky’s face. After that, he bears her whipping quite happily—even though it is the very worst one Mr. Dobbins has ever dealt. Mr. Dobbins tells Tom he has to stay after school for two hours, and Tom bears even this unspeakable punishment with good cheer. When his detention is over, Becky is waiting to thank him.