In the distant future, many years after the outcome of the Gum War, two friends named Beth and Shermy recover a rusty old mechanical arm that once belonged to Finn after it is dropped by a Prize Ball Guardian.

A look at what Ice King and Marceline were like 996 years ago.

Part 3 of a three-part episode. Finn and Jake chase the Lich through a dimensional portal and meet a wishmaster. After the Lich wishes that humanity never existed, Finn wishes that the Lich never existed.

The Ice King and Marceline bond over song and memories.

Part 2 of a three-part episode. Finn and Jake chase the Lich through a dimensional portal and meet a wishmaster. After the Lich wishes that humanity never existed, Finn wishes that the Lich never existed.

While dwelling on a joke he told to Flame Princess, Finn finds himself trapped in a strange pillow world.

After a magic spell backfires, the Ice King reverts back to Simon, and seeks help from Finn, Jake, and Marceline in order to get Betty, his former fiancée, back.

Finn and Fern's carefree visit to some old ruins turns disastrous.

A long lost artifact causes Princess Bubblegum to harken back to the creation of the Candy Kingdom.

Kim Kil Whan tasks Jake and Finn to investigate reports of a haunting in one of Kim Kil Whan's properties "Joshua and Margaret Investigations" since something in there traumatized his top employee Renny Hamlond and does not pay any rent for inhabiting the place.

When the Lich is accidentally freed from its amber prison in Princess Bubblegum's Castle, Finn and Jake must head forth to stop it from regaining its full power, all while being pestered by the Ice King to give him their blessing to marry Princess Bubblegum.

Marceline's evil father goes on a soul-sucking rampage after Finn and Marceline accidentally release him from the Nightosphere.

Princess Bubblegum recovers from being dropped in the Well of Power by the Ice King; however, she is altered and her condition leads to an unlikely final showdown with one of the greatest evils in order to save all life in Ooo.

When Finn starts sleepwalking and dreaming about the Green Lady he filed away in his memory vault, Jake and BMO help him tap into his repressed memories to uncover a secret past. Who is the Green Lady? And how is she connected to Finn?

After saving Finn the human during a battle between the candy kingdom and the fire kingdom it is discovered that LSP is made of anti-elemental magic and restores Ooo to it's former state.

BMO accidentally deletes his core system files. Finn and Jake disguise themselves as MOs to infiltrate the MO factory and save BMO from a memory wipe.

The friends learn the story of what happened to Ooo, while Betty continues her attempt to reach Simon, but she's interrupted by someone out to steal her magic.

While safeguarding a frightened Sweet P, Finn is led into a confrontation with an old foe.

Finn and Jake, as ambassadors of the Candy Kingdom, travel to a powerful new city-state in a last ditch effort to stave off war.

Finn and Jake decide it's time for Finn to get a new sword. Finn reluctantly buys a grass sword from a mysterious old man, but the sword turns out to be cursed! And unfortunately for our hero, all sales are final.

Finn, Jake, and BMO return from their voyage to a radically changed Ooo.

The Snow Golem visits the Fire Kingdom and finds an unlikely follower.

Finn receives a bag full of miniature versions of his friends.

Finn, Jake and Ice King break into the Ice World to confront the power-hungry evildoer responsible for the chaos in Ooo and try to rescue Betty.

After going to the Fire Kingdom, Finn becomes taken over by fire. LSP has to save him before he destroys the candy kingdom.