"Moe" is actually revealed to be AMO, who attempts to destroy BMO and steal Finn and Jake for itself.
At the treefort, 'Moe' is reading deals on deli meat from a newspaper. Finn and Jake are bored so they want to do something else. 'Moe' rejects wanting to listen to NEPTR rap, and instead says that they can play a video game, his only game; Hangman. Finn and Jake are excited but soon retract their joy when they realize Hangman is a word guessing game.
At the MO factory, BMO and ALLMO try to find a way out of the trash compactor. BMO suggests using trash to climb out of the compactor.
At the Treefort, Finn and Jake get bored with Hangman after correctly getting Burgess Meredith, but Jake doesn't know "what" that is and gets fed up. He and Finn depart to fight a real Hangman while 'Moe' remains and pouts.
BMO has successfully climbed into an air vent and crawls through to AMO's room. ALLMO explains that AMO was the first of their kind, built to receive love, as BMO was built to give love. ALLMO explains that AMO could not think beyond itself and thus shunned others in a cruel fate. BMO opens a door to the compactor to get ALLMO out of there while saying that as a birthday wish from Moe, he'd like him to fix AMO. ALLMO states that this is impossible as Moe "went offline yesterday."
BMO replies that he is at the Tree fort right now, to which ALLMO panics and asks if he has lasers and cannons on the top of his head. BMO says no but realizes that he is wearing a giant wig so it's plausible that he does in fact have weapons, and is a danger to Finn and Jake. ALLMO thinks that he is one who sabotaged that MO factory and asks BMO to carry it's form, stating that BMO is stronger than he knows.
Outside the Tree fort, Finn and Jake are returning from their quest to find and fight a hangman, but return empty handed. They find 'Moe' outside crying and legless, claiming bandits stole his legs. He leads them to a shed behind the Tree fort where NEPTR sleeps, saying he did it and to throw him out. Jake checks out NEPTR, who has a dent on his head area. 'Moe' tells them to forget about NEPTR as they love him, and the BMO is trash. Finn and Jake take offense that as 'Moe' takes off his wig, grows a new pair of legs. changes his voice and reveals that he is AMO. He yells that the real Moe is dead. AMO conjures up 2 dark metallic balls that he hurls at Jake and Finn, knocking them out.
BMO returns with ALLMO in tow, and asks AMO where Finn and Jake are. AMO avoids the question and flees, with BMO in pursuit. AMO stops at the end of a cliff. AMO reveals that he carries the back-up drive of Moe in a red drive he had on his head. In a flashback, AMO is seen returning to the factory to confront Moe about himself. Moe is dying and gives AMO his back-up, requesting that that back-up drive be sent to space and settled with the stars. AMO rejects this, using the knowledge from Moe's back-up to destroy the factory. BMO wants to secure Moe's back-up, but AMO fires dark metallic balls at him, damaging his screen face and arm. As AMO keeps firing, BMO keeps running up and as AMO conjures up another ball, BMO jumps and grabs it as AMO fires, pushing him off the cliff. AMO falls and his heart turns grey. BMO holds the back-up of Moe as he gazes over to see where AMO landed just as ALLMO lurches up the cliff with Finn and Jake.
BMO is asked by ALLMO to return to the factory to be the leader, to which he declines and says he just needs some time alone after having killed someone. BMO reflects on how he feels more grown, and alone now that Moe is gone. He realizes that he isn't the same as AMO, and not just limited by Moe's creation since he is able to think about the world. BMO rests by the back-up and accidentally activates it to a reflection of when Moe first made BMO and let him into the world.
- This is Adventure Time's second Christmas-themed episode since season 3's "Holly Jolly Secrets Part 1 and Part 2."
- A preview of this episode was shown at NYCC 2015.
- "Moe's" true identity was foreshadowed in the title card of the episode. Notice that BMO's reflection on the ice is clear and still, while "Moe's" is distorted.
- The Trash Compactor is reminiscent of the trash compactor from the Star War's franchise's Death Stars.
- When Finn and Jake play Hang Man, the game spells out Burgess Meredith. Burgess Meredith was a real-life actor known for his roles in The Twilight Zone, Penguin in the 1960s Batman television series, and Mickey Goldmill in the Rocky films.
- Chuck McCann, Moe's voice actor also co-starred with Burgess Meredith in the 1978 film Foul Play.
- This is a half-hour special episode.
- This is the last episode of Adventure Time to air in 2015.
- AMO's room was seen for an instant as BMO fell through the MO Factory in "Be More."
- Finn and Jake wear the same sweaters they wore at the end of "Holly Jolly Secrets."
- At the end, we can see MO's memory drive projecting a memory of BMO and outside the window, a construction of "the sleeping fire giants" which we've seen in episode "The Cooler." This may indicate that Moe constructed them, and the Flame People adopted them into their pantheon as the creators of the Fire Kingdom, according to Flame Princess's song.
- It is revealed that Moe has finally succumbed to old age.