The family wins a trip to Delaware, but Homer refuses to pay the tax on the ticket, so they ride the rails, and meet a hobo who sings and tells them some tall tales. First is the story of Paul Bunyan, with Homer playing the role of Paul as a giant doofus (a natural role for him). Next is Lisa as "Connie Appleseed," who tries to convince the pioneers to eat apples instead of Mastodon. The third story isn't really tall, but a Mark Twain-style tale about Tom Sawyer (Bart) and Huckleberry Finn (Nelson), who go on the run when Huck won't marry Becky (Lisa).
After the Simpsons win a trip to Delaware, Homer refuses to pay a $5 airport tax for his flight. The family jumps onto a freight train and meets a singing, although clearly weird, hobo who tells them three tall tales.
Homer plays Paul Bunyan, starting with his birth where his mother afterwards asks for whiskey. Many years later as a grown giant he is a great burden on local townspeople, as he crushes their houses and consumes all their food (along with anyone near it at the time). Eventually, the townspeople drag him out of their town after they drug him with beer and Jamitin (as seen in the program where Ned Flanders, Rod Flanders and Todd Flanders create their own film). Out of loneliness, he carves a block of stone from the mountains into a blue ox that he calls Babe, who is rendered alive by an electric shock, similar to Lightning, which apparently originated from the northern lights. Homer later meets Marge, and though she is initially frightened of him, the two fall in love. When a meteor is soon to hit the town, the townspeople call Paul back to help them. Paul obliges and throws the meteor towards Chicago, starting the Great Fire there, but not before it hits him in the backside.
After the hobo has told this story, Lisa points out that Paul's size kept varying throughout the story, the hobo shrugs her off and he asks them for a sponge bath as compensation. Disgusted, Homer is forced to oblige, as nobody else will do so, but the hobo does not mind anyone seeing his nakedness.
The hobo's second tall tale is loosely based on the legend of Johnny Appleseed, except Lisa portrays him, and her name is adapted to "Connie Appleseed". Connie is part of a wagon train, and all of the travelers shoot and eat great numbers of mastodon [Columbian mammoth]. Connie who is against the practice, states "If you don't stop this slaughter, you'll wipe out the mastodon." After which they all ridicule her, she is worried that no one is eating a renewable source of food, but a voice guides her to an apple tree and finds some apples for the pioneers to eat, unaware that it was Hans Moleman sinking in quicksand. The pioneers reject the apples (Homer spits them out in disgust when he realizes they are apples and not mastodon testicles) and leave Connie. Eventually, she changes her last name to "Appleseed", and leaves to journey across North America and plant apple seeds wherever she goes. Meanwhile, the Simpsons change their surname to "Mastokill" and they succeed in killing all the bison, leaving them with two. When the others realize they can breed the two mastodon, Homer just shoots and kills them. Just as they are about to cannibalize Homer, Connie returns and offers them apples. They like them, and Homer is spared, even though Moe Szyslak is seen eating him and asking, "What, so now we're not eating Homer?"
As Lisa points out before the story begins, this isn't an actual tall tale, but a story that the hobo tells based on Mark Twain's story about Tom Sawyer, portrayed by Bart, and Huckleberry Finn (Nelson). Huck is caught holding hands with Becky (Lisa) and is forced to marry her by her father (Homer). During the wedding, Homer points a shotgun at Huck, and at that time it's revealed that this is exactly how Homer and Marge got married, with Abe Simpson still pointing his shotgun at Marge. Huck dodges this marriage and goes on the run with Tom, leaving Missouri for Missoura. However, they are chased by townspeople led by Becky's father and their families. They flee to a river boat, but Moe throws them overboard into the Mississippi River and the towspeople catch them. The scene shifts to Tom's and Huck's funeral. Tom and Huck appear to be secretly watching the proceedings from the rafters, until Reverend Lovejoy orders their bodies lowered into the caskets, revealing that Tom and Huck are actually dead.
The family arrives in Delaware and disembarks from the train, but the hobo reminds them that they owe him two more sponge baths as compensation. Homer promises to catch up with them in an hour and volunteers to stay behind to do the dirty work.