The episode begins with Finn and Jake waking up in a pile of bananas in a jail cell with their memories of how they arrived there completely erased. The jail guard comes and tells the two that they're in the Nightosphere. After asking how they can get home, he explains that they cannot unless Hunson Abadeer allows them. Finn and Jake, along with other demons, are then set free because they cannot leave the Nightosphere anyway. They climb up through a hole and look around to get a good view of the Nightosphere. Afterwards, Finn and Jake ask for help from a Half Monster Demon, who tells them to climb into him and he will carry them to the Teller.
After being dropped off at a river full of demons, a traveler explains to them that they have to wait in a line. They spend almost 28 days waiting for their turn to see the Teller (though the time elapse could have just been a joke). When it is finally their turn, they have to stand in another long line. In that moment, a storm cloud appears in a mist and starts killing all the demons that were there to ask Hunson Abadeer questions, so Jake and Finn hide behind a rock. They barely escape, and follow the cloud to its castle. There, they fight their way back to the portal in order to get home.
They go into the portal and Hunson Abadeer follows them. Finn fights him and cuts his head with his Demon Sword, which reveals that the ruler was really Marceline all along. When they get back to Ooo, Marceline closes the Nightosphere portal and tells them to never come back. Finn claims they must go back to discover the truth.
This episode continues with its second part: "Daddy's Little Monster."
Mentioned and pictured
- Hunson Abadeer (both pictured and mentioned)
- Peppermint Butler (pictured)
- Abraham Lincoln (pictured)
- BMO (mentioned)
- Elder Toad (mentioned)
- It is revealed in this episode that Marceline's dad has an actual name, Hunson Abadeer. Throughout the episode, Finn and Jake refer to him as "Hunson."
- Abraham Lincoln can be seen with the Lord of Evil in a picture, this being the first time Abe is shown in the actual series.
- Another picture shows Marceline as a child standing next to her father on the left and another woman standing in the right who has a striking resemblance to Marceline. This may be her mother.
- In one of the pictures, Peppermint Butler is seen playing golf with the Lord of Evil.
- Jake spoke in Japanese in this episode - albeit broken. After cheering up Finn, he said "‘(上手で頑張ってね）Jouzu de Ganbatte ne" - which roughly translates as "Have faith and go forth!"
- Some demons mispronounce the Lord of Evil's last name, saying "Aberdeer."
- John DiMaggio (the voice of Jake) performs the voice of the Teller in this episode.
- In April 5, 2020, the 10th anniversary of Adventure Time, Olivia Olson revealed in the live stream that this is her favorite Marceline episode.
- When Marceline reveals herself Finn's sword disappears, it reappears when she tells them to stay away from her forever.
- As Jake says "Hunson Abadeer? Heheh.. Alright.", his mouth is not synced with his dialogue. He appears to be saying "Hunson Abadeer? Heheh.. Funny."
- When the Boat Demon is first shown, his eyes are black. However, in all of his subsequent scenes, his eyes are green.
- The appearance of The Nightosphere and its denizens appear to be directly inspired by the paintings of 16th century artist Hieronymus Bosch. Particularly the third panel of his triptych painting The Garden of Earthly Delights.
- During the first recording of the Nightosphere, a creature floats by that looks similar to a Ghast from the sandbox game Minecraft.
- As the "blood mist cloud" retracts into the tower after attacking the line, a clinking sound can be heard, reminiscent of the sound heard as the smoke monster on Lost retreats.
- The boat demon rowing over the other demons' heads is similar to the demon Phleygas, in Dante Alighieri's poem Inferno, who ferries over the river Styx, which is filled with wrathful and sullen sinners.
- The whole beginning sequence of them forgetting how they got somewhere is similar to the movie The Hangover. Later on they find some videos on Jake's flipphone, which also bears similarities to the ending of The Hangover.
- During the panorama scene, a line of cloaked and hooded figures can be seen climbing up a tower and then leaping off, while chanting is heard. This bears a resemblance to the animation in Monty Python and the Holy Grail when a line of monks each jumps in succession from a diving board while chanting.
- Finn and Jake have 42.000.000 number in the queue. Meanwhile, "42" is an "Answer to the Ultimate Question of Life, the Universe, and Everything" from The Hitchhiker's Guide to the Galaxy created by Adams Douglas.
- The amount of time FInn and Jake spend waiting in line (2 + 4 + 8 + 13 days + 18 hours) equates to 666 hours in total. 666 is known as the "number of the Beast" and is associated with the devil.
- The hair style that Marceline wears is the same as in "It Came From the Nightosphere," which is coincidental because Hunson Abadeer was in both episodes.
- After Finn and Jake have been released from their cage in the dungeon, a creature that resembles a Lemon Child can be seen writhing in the background.
- The presentation of the Nightosphere was similar to the Land of the Dead in the episode "Death in Bloom." Also, the song played when F&J entered the Half Monster Demon, were the same played during the same scene of the presentation of the Land of the Dead.
- This episode was previously titled "They Went to the Nightosphere," and was renamed. Some sites such as T.V. Guide and Dish Network still used the old title. The current title was used as a former title for the episode "It Came from the Nightosphere."
- This is part one of a two-part episode, and originally aired together with "Daddy's Little Monster."
- There are subtle indications that the Nightosphere ruler is a different entity from Hunson Abadeer, which may help viewers to guess that its identity is Marceline. Compared to her father in their respective Nightosphere forms, Marceline's demonic head is noticeably smaller, has more tentacles, and some features of her head and suit have different colors.
- Hunson Abadeer's picture with Peppermint Butler further proves Peppermint's connection with 'evil'. In "Death in Bloom" it is revealed that he knows Death, besides that at the end of the episode he told Finn and Jake he wanted their flesh as payment for helping them and that he would take it from them while they sleep as his eyes started to turn somewhat demonic (although he never actually did that to them). Also, in "You Made Me" when Finn wants to see Peppermint's aura he says "You don't wanna see that!" implying that they will not like what they will see and/or that he does not want them to know his true nature.
- ↑ Olson: "'Favorite Marceline episode?' I like, um, I like one Finn and Jake go to the Nightosphere and [...] I think it’s 'Back to the Nightosphere'?"