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.

The Ice King and Marceline bond over song and memories.

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

An unexpected revelation from Susan leads Finn closer to answers about his past.

Finn and Jake follow the Lich to the Citadel, where Finn meets his long lost dad. But just how far does the apple fall from the tree?

Trapped and alone, Finn must unravel the riddle of the weird cave with no exit.

Finn confronts the power behind Founders Island, but will he ever return home to Ooo?

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.

A visit from the Lich King sheds light on Ooo's secrets.

As the sun rises on her last day, Marceline recalls her long extraordinary life.

Finn and his friends journey to a last refuge called Founders Island.

In order to find Finn's father, Finn and Jake must commit a cosmic crime...unless the Lich beats them to it.

Following an ally's memorial service, Jake begins acting strangely.

The final confrontation begins. Who will survive?

Finn and Jake crossover into Farmworld Finn's dimension.

While exploring some futuristic ruins, Susan sees glimpses of a familiar girl.

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

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, Jake and Orgalorg converge with the comet and meet their destiny.

On the eve of battle, Marceline's archenemy comes to her with a strange proposal.

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

Finn and his friends must come together as a genuine band in order to open the gate of the Door Lord and get back their taken items.

Five foes from Marceline's past come back to cause trouble for the Land of Ooo.