The Lich

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Adventure Time - Season 4 - Episode 26

Adventure Time - I Remember You

About this Adventure Time episode:
Adventure Time - I Remember You is the 25th episode of Adventure Time season 4.
The episode begins with Finn having a dream about the Lich-possessed snail using the Enchiridion to attack Billy. Finn then wakes up and tells Jake about his dream, who - after hearing that the Cosmic Owl appeared in the dream - believes it is a premonition. The two go visit Billy, and tell him about the dream. Billy realizes the importance of the dream, and the three of them set out to stop the Lich. After they head out, Billy tells them that they need to collect all the magical gems from all the princesses and Ice King's power crystals that protect them from the Lich. With only one gem left, Finn finds the Enchiridion in Billy's knapsack. Billy reveals that the book has magical properties, and after activating it a certain way, the circle on the front opens up showing 9 slots where all the gems go in, and it shows a brief diagram about what would happen if all the slots where filled.
A holographic being named Booko appears and explains that when all the gems are placed in the book, a portal to the multiverse will be opened. Billy claims that he is going to throw the Lich through this portal. Finn and Jake then set off to get the last gem: Princess Bubblegum's. Finn and Jake try to take the gem, a scuffle ensues, and the duo manages to get the gem. Once outside, Finn puts the gem in the final slot. Lights start to flash out of the stones on book. Then the book starts to shake while the pieces start to fall off as the Enchiridion turns into a black block. As Finn is running, Billy tells Finn to hurry. Princess Bubblegum then runs out telling Finn that Billy is really the Lich.
Just as she says this, one of the Gumball Guardians gets up, detecting the Lich, and blasts Billy revealing that half of Billy's face is actually the Lich's. The Lich then asks for the book, but Finn smashes the book with his knee. However, his action accidentally opens up a wormhole. The Lich tries to pass through but Jake grabs him. Finn and Jake then try to stop him from going through, but are inevitably pulled through. The scene dramatically changes; Finn - in a completely different art style - is playing his flute with Jake, who appears to be a regular, non-talking dog. The two are sitting outside a small house with a barn next to it. His mother calls him in for what she says is "something important," and the episode ends with Finn assuming he has done something wrong and he and Jake quickly run inside.