Faced with spending his whole Saturday whitewashing Aunt Polly's fence, Tom persuades his friends to do the work for him and to pay for the privilege too. Tom meets Judge Thatcher's niece, Becky, and immediately falls in love with her.
Tom and Huck visit the graveyard at midnight, intending to use a dead cat to cure warts. But instead of the devils they expect, three grave robbers arrive and the boys witness the murder of the doctor.
Tom and Huck decide to hunt for buried treasure, and after having no luck digging around dead trees, they decide to try a haunted house. But before they get a chance to hunt for the treasure, Indian Joe arrives.
After searching around town all day, Huck finally finds Indian Joe plotting to take revenge on Widow Douglas. Meanwhile, Tom and Becky leave the school group to go exploring on their own, but get lost in the caves.
Tom and Huck are rich, and Widow Douglas and her sister take pity on Huck and adopt him. But wearing fancy clothes and being civilized doesn't suit Huck at all and he soon gets tired of it and runs away.
Pap Finn has returned and is determined to get his hands on Huck's money, so he kidnaps Huck and locks him up in a deserted cabin while he tries to convince the Judge to hand over what he claims is rightfully his.
Huck eventually escapes from the cabin where his father locked him up, and sets about making it look as if he's been attacked. Finding the cabin empty, Judge Thatcher suspects that Pap Finn has murdered Huck.
The Duke and Dauphin turn to acting and stop at a town to put on a show, but the locals don't appreciate their talents. Forced to leave the town in a hurry, Huck and Jim start to have doubts about their guests.
Huck continues to pretend that he's Tom when the real Tom arrives and confuses things even more by introducing himself as Sid. Tom agrees to help rescue Jim but insists on doing things the way they are in the books.
Jim is recaptured while helping the doctor look after Tom. Then Aunt Polly arrives unexpectedly, and the truth about Tom and Huck's name-switching comes out, along with their involvement in Jim's escape.