|The following information is from the Adventure Time comic book series. It may not be part of the same canon or continuity as the animated series.|
Adventure Time #54 is the fifty-fourth issue of the Adventure Time comic book.
Finn and Jake are sheriff and deputy of a wild west town...or are they? Is this even real?!
Finn and Jake are Western cowboys in the middle of chasing a criminal through the desert. They all happen to be riding giant desert snails. Jake says they should be close enough to catch the criminal on foot, so Finn hops off and grabs the man by the beard. He then makes the criminal drink chamomile tea and go to sleep. Later that night, they have set up camp, and Jake complains about how slow the snails are. Finn says the snails are sturdy, have cool shells in the heat, and don't need water. Jake estimates that they aren't far from Lemon's Folly, and Finn adds that they can resupply and mail the criminal back to jail. Jake then asks how long they'll live this way. Finn says he has to find his past and will search all of Ooo until he does. Jake says he'll stay with him until then. They both feel nervous about being close to the edge of the world, though. They agree to go back east as soon as possible and go to sleep.
The next day, in Lemon's Folly, a cactus person is being hassled by a snake. The snake demands the cactus' lemons as taxes for the Hiss Boys Snake Gang, but Finn and Jake confront him. The snake, named Clem, tells them that the Hiss Boys run the town. Knowing this to be a threat, Finn punches him in the face. Clem is completely surprised and calls that punch a mistake. He goes for an attack, but Finn hits him again. Trying to hide a humiliating retreat, Clem tells them that he's going to get the entire gang to destroy the town, and even bring the boss, whom the townsfolk fear. Clem retreats and the townsfolk are upset at Finn and Jake. The two feel they really messed up, but Mayor Lemonhope says they couldn't have known. He also tells them that he founded the town at a lemon mine, but the Hiss Boys take a lot of the supply. Finn asks if he and Lemonhope have met before, but Lemonhope says they haven't. Lemonhope goes to organize the fleeing before the town is destroyed, but Finn tells the mayor that he and Jake are vigilantes and can stop the Hiss Boys at their hideout. Jake reminds him that they were going to head east away from the world's edge, but Finn persuades him to beat the snakes first.
At the hideout of the Hiss Boys, Clem has told the other snakes what happened and they are in support of destroying the town. Suddenly, Finn and Jake make their entrance by punching some of them. Clem asks how they found the base, and they respond that they followed the slither path in the sand. Jake is grabbed by a bunch of snakes acting like one humanoid being (complete with clothes). Finn assumes it's the boss, but the real boss reveals herself to be Marceline. Finn recognizes her, surprising everyone. The two of them remember that they're friends, but Jake doesn't. When Clem is about to ask Marceline about destroying Lemon's Folly, she yells at him and the rest of the snakes to get lost, which also makes Jake remember her. She asks what's going on, and Finn realizes that this life isn't their real life. Jake is happy to remember that they don't ride desert snails. They question why they were in a wild west world, and Finn thinks he knows where to get answers.
The three of them scale the walls before the edge of the world, although Jake is still freaked out by it. Marceline asks what they expect to find, and Finn guesses that it could be space, in which they would have to ride the snails in the opposite direction. Upon reaching the top, they see a mountain-sized BMO. They remember BMO as their friend, and Marceline figures giant BMO is involved in the situation. They go on to talk to them.