Tom joins the Cadets of Temperance and vows to give up smoking and profanity. He discovers that abstinence makes a vice more attractive.
He looks forward to Judge Frazer dying, for he will have an elaborate funeral. At first, it seems the judge will recover, but then he dies. The cadets parade around.
When Tom is free once again to pursue vice, it no longer seems as attractive.
Tom amuses himself various ways over vacation, like trying to start a diary (until it is abandoned because he has nothing to write about). Sometimes groups pass through and provide entertainment—like minstrels and a circus.
It rains on July 4th, and the senator who makes a guest appearance was disappointing because he was nothing like they said he was.
Becky returns to Constantinople for the summer.
Tom catches the measles. After he recovers, he discovers that everyone—even the children—have gotten religious due to a recent revival. Even Huck Finn has fallen victim.
Tom has a relapse. When he gets well again, the boys are back to their old ways.