Huck and Jim drift away from Jackson’s Island, undiscovered by the men looking for them. At dawn, they tie up their raft on the Illinois side of the river and hide it, lying low there all day while Huck recounts what Mrs. Judith Loftus told him. Come dark, Jim builds a wigwam on the raft, in which a fire can safely be built. By night, the pair drifts downriver on the raft, passing silent cities like St. Petersburg and St. Louis as they go, the inhabitants of which are all asleep.
To remain free from their pursuers, Huck and Jim have to impose rules on themselves, like not lighting fires save for in the wigwam and only travelling by night. Freedom isn’t so much an absence of rules here, as self-reliance and discipline. Huck and Jim are also uncannily distant from society: while others sleep, they are awake.
At nights, Huck goes into town to buy provisions and supplies. In the mornings, he slips into cornfields to “borrow,” that is, steal produce. Huck says that Pap told him that it wasn’t harmful to “borrow” things if you mean to pay for them eventually, but the Widow told Huck that such “borrowing” is really just stealing. Huck and Jim discuss this and consequently decide not steal any more crabapples or persimmons. Nevertheless, Huck says that he and Jim “lived pretty high.”
Huck and Jim have the perfect freedom to choose which moral system they will subscribe to: Pap’s, which is convenient but harmful to others, or the Widow’s, which imposes hardships on Huck and Jim but not on others. The two, committed to the well being of others, freely decide not to steal—and still live well! One can be free and good at once.
One night during a storm, Huck and Jim see a wrecked steamboat. Huck wants to board it and have an “adventure,” in the spirit of Tom Sawyer, but Jim “was dead against it.” Huck, however, convinces a reluctant Jim to go against his better judgment, supposing that the pair will find valuable things onboard the boat.
Even though Huck is morally maturing, under Tom’s influence he is still childish when it comes to balancing costs and benefits. He thinks endangering himself and Jim is worth potential profits. Jim knows better, but goes with the willful Huck to protect him.
Once onboard the steamboat, Huck and Jim realize that they’re not alone. They hear voices, one of a man pleading for his life, the other two of men planning to kill the man in order to protect themselves, because they think he will betray them to the State for having broken the law. Huck eavesdrops as the two men decide not to shoot the man, but rather to escape the steamboat and let the third man drown in it as the storm raises the water level of the river. Killing a man, one of the two says, just “ain’t good morals.” As the men start out, Huck tells Jim to make for the raft that is lashed to the steamboat. But, when Jim does so, he discovers that the raft has broken loose, stranding him and Huck.
In contrast to Tom’s make-believe gang of children, the gang Jim and Huck encounters on the doomed steamboat are very real, vicious, and murderous—but, like Tom’s Gang, this one is just as arbitrary in its moral code. It is ironic that one of the thieves refuses to shoot a man, but is willing to let a man drown. This thief seems to want to excuse himself from the guilt of murder, even though his action here has the same effect as murder. His rule is absurd.