The setting is a beautiful, glorious Saturday morning. It is the kind of day when a boy like Tom wants to be out playing but instead has been punished by Aunt Polly. He has been set to work in front of her house to whitewash her picket fence.

The conflict is that Tom doesn't want to be doing this menial labor when he could be enjoying himself. Therefore, in an iconic and very famous scene, he uses his wits to persuade other boys that whitewashing a fence is an enviable task. He accomplishes this by acting as if the whitewashing is great fun and by showing extreme unwillingness to let others help. The text notes:

Tom gave up the brush with reluctance in his face, but alacrity [quick happiness] in his heart. And while the late steamer Big Missouri worked and sweated in the sun, the retired artist sat on a barrel in the shade close by, dangled his legs, munched his apple, and planned the slaughter of more innocents.

Tom realizes that by withholding an activity from others it becomes desirable. Eventually, boys are trading him things for the "privilege" of painting. The narrator tells us:

If he [Tom] had been a great and wise philosopher, like the writer of this book, he would now have comprehended that Work consists of whatever a body is obliged to do, and that Play consists of whatever a body is not obliged to do.