A party rushes down to the cave, unlocks the door, and finds Injun Joe starved to death inside. He evidently has eaten the few bats he could catch, used every candle stump he could find, and made a cup out of rock and placed it under a dripping stalactite to catch a spoonful of water a day. “Injun Joe’s Cup,” Twain informs us, has since become one of the chief tourist attractions in the cave.

The morning after Injun Joe’s funeral, Tom tells Huck his theory that the gold never was in Room No. 2 at the Temperance Tavern. Instead, he believes that it remains hidden in the cave. That afternoon, the boys take a raft down to the place where Tom and Becky exited the cave and crawl inside. Tom comments on how much he wants to start a gang of robbers and use this part of the cave as a hideout. The boys discuss how grand it would be to be robbers and eventually reach the place where Tom encountered Injun Joe.

Tom points out a cross that is burned on the wall of the cave and tells Huck that this, not the tavern, must be where the gold is hidden. Huck becomes frightened that Injun Joe’s ghost could be lurking around, but Tom points out that the cross would keep him away. Comforted by Tom’s words, Huck helps him search the area. The boys find nothing and decide to dig under the rock. There they find a collection of guns, moccasins, a belt, and the treasure.

The boys decide to leave the guns behind, reasoning that they will be useful for their band of robbers in the future. They drag the gold out of the cavern and put it on their raft back to St. Petersburg. On their way to hide the treasure, however, they encounter the Welshman, who insists that they accompany him to a party at the Widow Douglas’s house. He sees the box they are lugging but assumes they have been collecting old iron.

Nearly every person of importance in the village has gathered at the Widow Douglas’s house. While the boys change into nice clothes, Huck tells Tom that he wants to escape out the window because he cannot stand such a large crowd. Tom tells him not to worry. Sid comes in and informs them that the party is being given in honor of the Welshman, Mr. Jones, and his sons, and that Mr. Jones plans to surprise everyone by announcing that Huck was the real hero. Sid then says, in a self-satisfied way, that the surprise will fall flat because he has already spoiled it. Tom yells at Sid for being such a nasty sneak and chases him out of the room.

At the supper table, Mr. Jones tells his secret and everyone pretends to be surprised. Widow Douglas then announces that she plans to give Huck a home and educate him. Tom bursts out, “Huck don’t need it. Huck’s rich.” Everyone chuckles at the joke, and Tom runs outside and brings in the gold. Everyone is shocked. When the money is counted, it adds up to over twelve thousand dollars.

The news of the gold shocks the village and inspires dozens of treasure hunters. The money is invested and provides both boys an allowance of almost a dollar a day—equal to the minister’s salary.

Becky tells her father about how noble Tom has been, and the judge decides that Tom should go to the National Military Academy and then become a lawyer. Huck, meanwhile, suffers terribly under the burden of being civilized. He bears wearing clean clothes, sleeping in sheets, and eating with a knife and fork for three weeks; he then runs away. The town searches for him, but to no avail. Tom finds him, eventually, sleeping in an abandoned slaughterhouse, and Huck tells his friend that he simply is not cut out for a respectable life. Widow Douglas makes him dress nicely and forbids him to spit, swear, or smoke.

Tom replies that Huck can do as he pleases, but if he wants to join Tom’s gang of robbers, he has to be respectable. Otherwise, he says, Huck’s sour reputation will drag down the whole gang. Huck agrees to try the widow’s house again for a month—provided that Tom allows him to belong to the gang.

Twain writes that the story must end here because it is strictly a story about a boy. Were the story to continue, he states, it would quickly become the story of a man. He adds that most of the characters in the story are still alive and that he might one day explore how they turned out.

In a way, the town rewards Tom for his disobedience. It hails him as a hero in relation to three actions that are marked by mischief—his return from Jackson’s Island, his testimony against Injun Joe, and his return from the caverns. A model boy would never get lost in a cave or be able to lie “upon a sofa with an eager auditory about him and [tell] the history of the wonderful adventure.” Tom’s adventuresome spirit leads him into risks that others would not attempt, and his payoff is heroism.

Twain’s message, however, is not that disobedience is a virtue. Others who disobey, such as Injun Joe, fall prey to Twain’s criticism without any heroic tempering. Although Injun Joe, Tom, and Huck are all inherently mischievous, Injun Joe harms others to satisfy his inclinations. Tom and Huck, though true to their mischievous natures, never allow themselves to harm others—they feel bad even about stealing bacon. A third category of characters in the novel includes those who obey outwardly but harbor malevolence on the inside—Sid, for example. These hypocrites are the subtle antiheroes of the novel.

After his triumphant return from the cave, Tom regains his sense of perspective and leads Huck back to the cave to find the treasure. Their plan for a “robber band,” which Tom will in fact establish in The Adventures of Huckleberry Finn, marks a return to the world of boyhood fantasy, as it resembles the pirate band they create on Jackson’s Island and the outlaws they pretend to be in Sherwood Forest. Tom and Huck also return to their boyhood mind-set in the cave when they argue about superstition. But the way Tom deflects Huck’s arguments, enabling the conversation topic to move beyond superstition so that the boys can get the gold, displays his increasing maturity.

When the Widow Douglas adopts Huck, not only his treasure but also his life become subject to adult control. As Huck and Tom change upstairs in the Widow Douglas’s house before her dinner party, Huck is so worried about the life that awaits him that he attempts to persuade Tom to escape. Tom dismisses Huck’s fears, promising to “take care of [Huck],” but Huck’s worries prove well founded. Not long after he and Tom go downstairs together, the secret of their riches is revealed, and they are quickly ushered into the daunting adult world.

Tom is far more ready than Huck to enter the adult community. When we first meet Huck, Twain writes, “Tom envied him his gaudy outcast condition”; now Tom urges Huck to embrace respectability. The Tom we meet in the first chapter, with jam on his face and mischief on his mind, has given way to a boy who defends the adult order by preventing Huck from escaping out the window. Tom is not yet a man and still has plans for a robber gang, but Judge Thatcher is already talking about sending him to the military academy and law school. When Tom finds Huck after he has attempted to run away from the Widow Douglas’s house, he couches his appeal to return in the language of childhood, telling Huck that he needs to be respectable to be in the robber band. But we sense that Tom is using this rhetoric to appeal to Huck because, with his newfound money and status, Tom has a stake in adult society that he wants to defend.

Twain’s closing words wrap up matters for Tom and Huck and usher them into adult society without actually showing them as adults. Their gold, which has been pursued without the adults’ knowledge as a kind of game, is no longer a game. The gold has become a business, so serious that Judge Thatcher, the most significant and authoritative figure in the adult hierarchy, assumes control of it. Gone are Huck’s plans to spend it all on candy, although on a dollar a day, he will happily be able to enjoy his share of sweets.

There is a note of sadness in Twain’s concluding statement that Tom’s story will soon become “the history of a man.” The woods and fields around St. Petersburg, where Tom plays Robin Hood, pirates, and Indians, have given way to the world of money invested at interest. The freedom of childhood, represented by Huck, has been absorbed by the adult order. The novel, which mixes a nostalgia for the carefree days of youth with illuminating criticism of adult society, cannot but regret the conclusion of childhood, even while recognizing—as Tom tries to enable Huck to recognize—the importance of moving toward maturity and sophistication.