Aunt Polly finds Tom in the pantry where he has been eating forbidden jam. As she gets a switch, Tom convinces her that something is behind her. As she turns, he escapes, leaving her to contemplate how he constantly plays tricks on her. She is concerned whether or not she is "doing her duty by him," but because he is her dead sister's child, she cannot bring herself to be harsh with him.
That afternoon, Tom plays hooky from school, and at supper that night, Aunt Polly tries to trap him into revealing that he skipped school. Tom is able to avert her questioning, until Sid, Tom's brother, squelches on him. Before Aunt Polly can say more, Tom escapes.
Heading into town, Tom meets a stranger, "a boy larger than himself" and dressed up like a "city slicker." He and Tom get into a fight. Tom gets the better of the other boy and follows him home. The boy's mother appears and calls Tom a "bad vicious, vulgar child" and orders him away. When Tom returns home with his clothes dirty and torn, Aunt Polly decides that, as punishment, he will lose his freedom on Saturday and will have to whitewash the fence.
On Saturday morning, Aunt Polly sends Tom out to whitewash the fence. Jim passes by, and Tom tries to get him to do some of the whitewashing in return for a “white alley,” a kind of marble. Jim almost agrees, but Aunt Polly appears and chases him off, leaving Tom alone with his labor.
A little while later, Ben Rogers, another boy Tom’s age, walks by. Tom convinces Ben that whitewashing a fence is great pleasure, and after some bargaining, Ben agrees to give Tom his apple in exchange for the privilege of working on the fence. Over the course of the day, every boy who passes ends up staying to whitewash, and each one gives Tom something in exchange. By the time the fence has three coats, Tom has collected a hoard of miscellaneous treasures. Tom muses that all it takes to make someone want something is to make that thing hard to get.