|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 #33 is the thirty-third issue of the Adventure Time comic book. This issue features a special preview, serving as the back-up story, titled "Over the Garden Wall," which was created and written by Patrick McHale and illustrated by Jim Campbell.
"Mnemonoid’s hold on Finn is proving to be stronger than anyone had thought and it’s taking the whole crew to band together to help their friend, only this time, there really might be nothing they can do. It’s up to Finn to stand up to Mnemonoid, if only he could find the bully."
Finn and Flame Princess (now Flame Queen) are traveling via flying platform as he tells her what the Mnemonoid did to him. A concerned Flame Queen tells Finn that this was twenty years ago and shows him the now-devastated Ooo. She explains that the Air, Water, and Desert Kingdoms caused it. They reach the Candy/Vampire Kingdom where a meeting is held, including Queens Bubblegum and Marceline, the Brunch Kingdom queens, and Jake. Finn tells them that the Mnemonoid ate his memories again and asks them to fill him in. Stunned, Bubblegum and Marceline declare that they're doomed.
They tell Finn that yesterday he told them he found a way to end the war and was going to tell them the plan today. Finn is surprised that a war is going on, as Flame Queen didn't have time to tell him. Marceline thinks they can trigger his memory by getting him up to speed, so Bubblegum uses a brain projection device she made in place of a comic, though subconcious images still appear. Using baby versions of Finn and Jake, she demonstrates that playful punching can lead to brawls between friends, which is basically where the kingdoms are. Marceline then takes over, showing that Desert Princess annexed the Water and Air Kingdoms to form the Mud Kingdom six months ago. By dominating and taking magic from other kingdoms, they grew stronger, even blocking out the sun with sand.
Unfortunately, Finn can't remember anything from this. While the others are resigned to losing, Finn does remember that his friends wouldn't just give up. Jake agrees and thinks they should try asking the Mnemonoid to return the memories. Bubblegum thinks it's ridiculous, but Jake says that they're stronger now than they were twenty years ago. They also point out that Finn's memories could restore peace, giving the other kingdoms reason to help. With everyone on board, they go out to recruit others, starting with Ice King (who brings along BMO and some penguins).
After recruiting several others, they are ready to face the Mnemonoid, only to realize they don't know where he is. Outside the comic panel, the Mnemonoid says that's his cue and enters. As he does, Mud Kingdom troops begin to invade. The Mnemonoid appears to everyone and states that he will keep Finn's memories, also advising they all leave. He traps them with his telekinesis when they refuse, so they enact their plan. Jake shapeshifts to get out and Marceline tackles the Mnemonoid, freeing everyone else. She and Jake then merge together. Jake hits the Mnemonoid and Marceline throws the other queens and princesses who also hit him, bringing him to the ground. Bubblegum demands he return Finn's memories or else they keep fighting. The Mnemonoid refuses and uses his telekinesis to not only trap them again, but also move the sand in the sky, letting sunlight through and killing Marceline.
The ones guarding Finn try to fight the Mnemonoid off, but are easily pushed aside. Finn's memories are eaten again, and he wakes up an elderly man in snowy mountains.
- In Bubblegum's subconscoius thoughts, she is wearing the same adventuring outfit first seen in Issue 20.
- Bubblegum points out the waving snail.
- In the very next panel, she makes a pose that resembles Rosie the Riveter.