"The New Frontier" is the eighteenth episode in the third season of Adventure Time. It is the seventieth episode overall.
Finn tries to stop Jake from embracing a dream that he believes foretells his final demise.
Jake has a Croak Dream involving a rocket ship and a Banana Man in space. He runs out of air after holding his breath too long and sees the Cosmic Owl. After he wakes up and tells Finn about the dream, they hear someone knocking on the door. Finn looks out the window and sees the Banana Man. Finn freaks out and throws Jake behind a large container, and hides there with Jake and tells him that the Banana Man is there. Finn looks outside again to see what he is doing. They decide to follow him to his house after he begins to walk away from the Tree Fort, and across the Grass Lands. They get to his house and go up to the Banana Man's window when he walks into his house. They see him turn on the T.V. and put on a helmet just like the one seen by Jake in his dream. He starts to dance along to what was on. Finn pulls out a crossbow and an arrow from his backpack, and uses some type of friction that creates fire when you rub your hands together, and blow in between your hands and small flames form. This sets the arrow on fire. After firing arrows at him to try to scare him away, the arrow that they used flies into the back of his home, and when Finn and Jake go there to get it they find his rocket ship in his backyard. Jake tries to ride it, despite Finn trying to convince him not to, because he says it is his destiny. The Banana Man walks into the backyard (holding glass, which was probably for the window) and sees them fighting on the floor. The rocket fails to launch since it did not have enough dynamite to blast off. The Banana Man drops his plate on glass on the ground, shattering it (in its own cutaway,) which in conjunction with the windowless vessel featured in the croak dream suggests that Finn's attempt to avert Jake's fate might actually have sealed it. When the ship lands on the ground it creates a hole, which Jake, Finn, and the Banana Man fall into. They fall into a pool of water which re-creates Jake's dream, only Finn is there so the Croak Dream does not come true. They find out that the Banana Man only wanted to borrow some sugar. After that, Jake then says that his Croak Dream was not real; unless he did not die since Finn was with him this time, meaning it was destined to happen again. The episode ends with Finn running after Jake, so that his Croak Dream would never come true. In the final scene, The Banana Man starts dancing along.
- This episode was originally titled "The Croak List," but it was "too spoilerish" according to Adam Muto.
- Banana Man's wall has pictures of bananas, a monkey, ice cream, an astronaut helmet, the Solar System and what appears to be some kind of war/air medal.
- The title card was designed by Andy Ristaino. 
- When Jake creates the diagrams of himself, Banana Man and Finn on his stomach, Finn's shape resembles Bueno the Bear.
- The original title sketch card had a picture of V838 Monocerotis, one of the largest known stars, but in the final title card, it shows a star cluster in the background rather than the actual star itself.
- In this episode, Finn starts a fire using only his hands, but in "The Hard Easy" neither Finn nor Jake are able to do it.
- The wrecked limousine outside Banana Man's house is similar to the one on the newspaper next to Simon Petrikov in "I Remember You."
- The numbers 8, 18, and 12 can be seen inside Banana Man's rocket, the marriage date (August 18, 2012) of background artist Santino Lascano.
- Jake is comfortable with dying in this episode, while in Jake vs. Me-Mow he agrees to kill Wildberry Princess to save his own life. This is most likely because the Cosmic Owl was involved in this episode.
- In "Dad's Dungeon," Finn claims he only cries when people die, and when Jake was about to die, he started crying, supporting the fact, although this episode aired before "Dad's Dungeon."
- The croak dream that Jake has in this episode fulfiills in the episode "The Comet," as Jake floats into space, and is later shown to be in a spaceship with Banana Man.
- The title of this episode is also the name of a legislative program introduced during the presidency of John F. Kennedy to comprise economic and social legislation as well as housing and minimum wage laws.
- The scene in which Jake tells Finn to let him go is a parody of the scene in Indiana Jones and the Last Crusade in which Indiana's father tells him to let go of the Grail.
- The final scene of the randomly-dancing Banana Man is a possible reference to the internet phenomenon the "Dancing Banana," which involves an animation of a dancing banana set to the song "Peanut Butter Jelly Time" by the Buckwheat Boyz.
- In this episode, Finn and Jake's house is filled with computers that resemble old Macintosh LCs.
- The scene in which Finn, Jake and Banana Man fall down into the underground lake might be a reference to Gandalf and the Balrog in The Lord of The Rings: The Two Towers falling into a subterranean lake under Moria.
- The Black luxury car seen outside of the Banana Man's house resembles a 1980 Rolls-Royce Silver Spirit Mark I.
- When Jake wakes up, Lady Rainicorn is not seen in the picture he has and right above it there is a frame with only a green background.
- When Finn and Jake find the rocket, there is no large tube near the dynamite, in the close up, it is there and a dynamite cartridge that was on the ground disappears.
- When Finn goes to light the fuse, Banana Man's stuff that was on the ground disappears, all the dynamite is set up in the rocket and the fuses are tied but when they found the rocket there was dynamite in the ground and the fuses were loose.
- When Finn says that they are out of arrows, the crossbow that was laying on the grass near his feet is gone.
- When Finn said that Banana Man was going to walk into the sun, his backpack seems to be up by his head instead of on his back.
- There is less detail on the Banana Man's rocket when Finn, Jake, and the Banana Man fall down the pit into the Underground Cave.
- After the rocket fails to launch and hits the ground, its legs are blown off. However, when the rocket is floating by underwater, its legs have reappeared.
- Jake's croak dream shows him floating in space near a perfectly spherical Earth, akin to the Earth prior to the Mushroom War (and not the true Earth as seen from space in "The Real You"). Since the "Earth" seen in Jake's dream actually turned out to be a miniature model of a planet, it is possible that the model was made before the Mushroom War. If the model was made by Banana Man or someone else in recent times, it can easily be explained that since no one has been in space since the fall of civilization due to the Mushroom War, no one would realize the planet's true shape and could imagine that Earth remains a big sphere as it always has been. Space travel was not possible because rocket ships had not been "re-invented yet." Either that, or he viewed it at an angle from which the giant crater could not be seen.