Holly Jolly Secrets

"Holly Jolly Secrets" is a special half-hour Christmas-themed episode of the Cartoon Network original series Adventure Time. It originally aired on December 5, 2011.

Part 1
Finn and Jake are trying to dig up a treasure Jake had found in the Dump and had buried without opening. When they get to the treasure Finn recognizes it, saying that he saw Ice King with it and burying it in a pile of boogers in the Dump. So they see that inside the suitcase is a bunch of tapes belonging to the Ice King and make plans for a secret tape watching.

Jake puts up flyers to warn people that the tape watch is for Finn and Jake only but the Ice King, while trying the William Tell trick on Gunter, sees one and goes over to the Tree Fort. At that very location Finn and Jake start to watch the tapes and see that they are video journals and get bored soon. After some snack making Finn and Jake think there might be a secret code hidden in the message.

To crack the code Finn and Jake call up Princess Bubblegum, who is the 'smartest person' they know, but the line is interrupted by the Ice King who wants to watch the tapes too. BMO sees Ice King from a window and warns Finn and Jake who hang up on the Ice King.

BMO then thinks of hacking the code but only comes with a picture of Gunter out of computer figures, and then Ice King decides that he had enough. He summons huge snow drifts that completely cover the Grass Lands as Jake starts to scream.

Part 2
The scene opens up with Jake screaming but he was actually singing Alouette. Jake is wearing a yarmulke and scarf. Then they decide to watch the Ice King's secret video, thinking that it might show his evil plans. The first video reveals that his life is stagnating, so he weeps, and BMO discovers a "code" in the pattern of his tears. Through a strange, random process, the code forms a picture of Gunter. The second video is of him recording the Wildberry Princess while in a cage in his palace. He was asking Wildberry how she felt about an event, and it turns out that Ice King was talking about why Gunter was standing in the corner (Gunter tried to eat the Ice King's socks).

In the Ice King's attempt to stop Finn and Jake from watching his secret tapes, he makes an army of snowmen. The Ice King breaks into the Tree Fort through the chimney. In the process, his blue robes become covered in soot, so he takes them off and covers himself with Finn and Jake's red tablecloth. Once inside, the Ice King lets the snowmen in through the front door, as Finn and Jake rush to finish watching the videos and determine the Ice King's evil secrets. The snowmen attack, but they are easily defeated, and BMO begins to play the final tape.

The third tape reveals that prior to the Mushroom War, the Ice King was a human named Simon Petrikov, who had a fiancée named Betty. He was an antiquarian, and purchased a strange crown from a dock worker in Scandanavia. He took it home to show Betty, and when he put the crowd on his head for a laugh, he lost consciousness. When he woke up, he had no recollection of his actions, but Betty had gone, never to be seen again. As the video progresses, Simon begins to look more and more like the Ice King as we know him. His skin takes on a blue tint, his hair begins turning white, and a beard slowly appears on his face. He is increasingly distraught about the loss of Betty, his "princess", and his actions while under the influence of the Crown. In the background of the video, we see an airplane flying over modern buildings, evidence of his life before the Mushroom War. Simon is aware that he is losing his mind, yet is unable to control it. In the end, he is accepting of his fate, and he begs for forgiveness for his actions to anyone who might come across his tapes.

When the video ends, it is revealed that the Ice King wasn't afraid of them finding out that he was once a human; rather, he was merely ashamed of having once worn glasses. (This shows us he has completely lost and forgotten any trace of his human, past-self, yet his desire to have his beloved Betty back lives on in his obsession with capturing Princesses.) Finn and Jake feel "a fleeting moment of empathy for the biggest weirdo in Ooo", and from this time on, they gather together once every year and wear Christmas sweaters and watch videos.

Cast
Note: Marceline, The Vampire Queen, Cinnamon Bun, Pepperment Butler, Phil, Mr. Candy Cane, Gumdrop Lass 2, Lady Rainicorn, Lumpy Space Princess, Tree Trunks, and Royal Tart Toter, appear at the end, but do not speak.