The opening sentence of Chapter 25 expresses the universal truth that sometime in the life of every boy there comes a time when he wants to search for buried treasure. This sentence leads to a continuation of the adventure that began in the graveyard and that runs throughout the plot of lesser adventures. That is, it propels the boys toward the inevitable confrontation with Injun Joe. This sentence also leads Tom and Huck to the discovery of the existence of buried treasure, the episode within the cave, and the discovery of the treasure itself.
When Tom explains the nature of buried treasure, he demonstrates his "book learning" and his love of the theatrical or romantic. When the boys discuss how they will spend the money, Huck Finn is the more realistic one: He wants to spend it all immediately on enjoyment because his pap (father) might hear of it and come back and take it all away from him. Tom, however, will spend some of the money on "fun things" but wants to save a large portion of it to use for things such as his marriage, thus indicating a more mature outlook.
The theme of superstition is reintroduced in these episodes. The boys are superstitious of Friday the 13; they believe treasure can only be found at the bewitching hour of midnight; they feel that a horrible dream about rats is dangerous; and they are aware of "signs" such as a haunted house, a skull, witches, dead people, blue lights, and ghosts that will affect their finding treasures.
