"The Adventures of Huckleberry Finn" tells the story of Huckleberry Finn's odyssey rafting down the Mississippi River with an escaped slave named Jim. Along the way they encounter a number of characters, which the author uses for social commentary.
The story begins in Huck's hometown of St. Petersburg, Missouri, where the strict Widow Douglas is raising Huck. Huck's alcoholic father, Pap, returns to town, and harasses Huck because he, as a result of his adventures in the previous book, "The Adventures of Tom Sawyer," has become quite wealthy. Pap kidnaps Huck and keeps him locked in a cabin until Huck escapes and fakes his own death before heading downriver. On the way, he stops by Jackson Island, where he encounters Jim, Miss Watson's slave who escaped after hearing talk of plans to sell him to a plantation. They stay at the island for a while, but quickly decide to leave after finding out that people had noticed smoke coming from the island and intended to search it.
Huck and Jim, who plan to catch a steamboat to the north after rafting down to the mouth of the Ohio River, encounter robbers, feuding aristocrats, and con artists who eventually sell Jim to a local farmer, who turns out to be Tom Sawyer's uncle Silas. People mistake Huck for Tom, and he goes along with it, hatching a convoluted scheme to free Jim when Tom arrives. During their escape attempt, Tom receives a gunshot wound, and the authorities recapture Jim. The next morning, however, it is revealed that Huck is not Tom, Jim is actually a free man since the death of Miss Watson, and Pap had died, which meant that everyone was free to return home for a happy end. Though Widow Douglas offers to adopt Huck, he has no interest in civilized life and runs away to head west at the end.