Summary

The Adventures of Tom Sawyer is concerned with the escapades of a young boy living in a Mississippi River town during a summer in the 1840s.
Tom lives with his Aunt Polly, his dead mother's sister, along with his half-brother, Sid, and his cousin, Mary. By the second chapter, Tom's mischevous character is revealed with the well-known fence whitewashing scene. Tom meets the new girl in town, Becky Thatcher, and falls in love with her. He begins an intense flirtation with her at school, which leads to his asking her to be "engaged" with him by lunchtime of her first day.
Tom's vagabond friend Huck Finn, the town drunk's son, asks Tom to meet him at the cemetery at midnight, to test the wart-curing properties of his dead cat. While there, the boys stumble upon the murder of Dr. Robinson by Injun Joe during a graverobbing attempt. Muff Potter, also part of the gang, is pinned with the crime by Injun Joe. Tom and Huck, however, are the only ones who know the truth.
Tom, Huck, and another friend, Joe Harper, decide to run away from St. Petersburg to Jackson's Island, in the middle of the Mississippi. There they live the life of pirates, frolicking day and night. After several days, the town prepares funeral services for the boys, by this time being convinced of their death. The boys dramatically return to town in the middle of the Sunday church services, and they are forgiven for their mischief.
As the murder trial of Muff Potter gets underway, Tom is racked by guilt over allowing a man he knows to be innocent to be convicted. On the final day of the trial, Tom is called as a surprise witness, and he proceeds to finger Injun Joe with the crime, who springs out of the window and escapes. Tom and Huck stumble upon Joe and a stranger at a deserted house on the outskirts of town, and learn of a stash of gold Joe is carrying.
Becky Thatcher invites many of the town's children to a picnic. Tom and Becky go wandering in a nearby cave, and get lost. Also in the cave is Injun Joe, hiding out. Just as Tom and Becky lose all hope of finding an exit, Tom finds an opening to safety. Huck and Tom return to the cave, find Joe's treasure, which was hidden in the cave, and become heroes in the town.

Sid

Sid - Tom's half-brother. Sid is a goody-goody who enjoys getting Tom into trouble. He is mean-spirited but presents a superficial show of model behavior. He is thus the opposite of Tom, who is warmhearted but behaves badly.

Injun Joe - A violent, villainous man who commits murder, becomes a robber, and plans to mutilate the Widow Douglas. Injun Joe's predominant motivation is revenge. Half Native American and half Caucasian, he has suffered social exclusion, probably because of his race.

Joe Harper

Joe Harper - Tom's “bosom friend” and frequent playmate. Joe is a typical best friend, a convention Twain parodies when he refers to Joe and Tom as “two souls with but a single thought.” Though Joe mostly mirrors Tom, he diverges from Tom's example when he is the first of the boys to succumb to homesickness on Jackson's Island. As the novel progresses, Huck begins to assume Joe's place as Tom's companion.

Huckleberry Finn

Huckleberry Finn - The son of the town drunk. Huck is a juvenile outcast who is shunned by respectable society and adored by the local boys, who envy his freedom. Like Tom, Huck is highly superstitious, and both boys are always ready for an adventure. Huck gradually replaces Tom's friend Joe Harper as Tom's sidekick in his

Aunt Polly

Aunt Polly - Tom's aunt and guardian. Aunt Polly is a simple, kindhearted woman who struggles to balance her love for her nephew with her duty to discipline him. She generally fails in her attempts to keep Tom under control because, although she worries about Tom's safety, she seems to fear constraining him too much. Above all, Aunt Polly wants to be appreciated and loved.

Tom sawyer

Tom Sawyer - The novel's protagonist. Tom is a mischievous boy with an active imagination who spends most of the novel getting himself, and often his friends, into and out of trouble. Despite his mischief, Tom has a good heart and a strong moral conscience. As the novel progresses, he begins to take more seriously the responsibilities of his role as a leader among his schoolfellows.