Once homeless and free to do as he pleased, Huckleberry Finn's situation has changed since he and Tom Sawyer found $12,000 in treasure.

Huck has been taken in by the kindly Widow Douglas and her more severe and disapproving spinster sister, Miss Watson, and he is having great difficulty adjusting to a "respectable" life.

While begging for food in a river town, Tom and Huck meet Mary Jane, a sweet-natured young lady who was recently orphaned and has $14,000 worth of gold hidden in her fruit cellar.

Tom naively believes the supposedly royal pair have "letters of mark" and are therefore entitled to do as they please, but Huck, who has befriended Mary Jane, decides to protect her.

Huck finds the gold, convinces Tom the Duke and King are no good and exposes the plot in front of the local sheriff and townspeople.