(Sorry about the early publish, the story accidentally formatted wrong)

[Y/n, Finn, and Jake are in the Ice Kingdom, sneaking past a penguin guard. Y/n looks exhausted and he has bags under his eyes.]

Finn: Our secret mission to capture the Ice King is underway. Though I probably shouldn't say stuff like that out loud.

Y/n: [yawns] Ya think...

[Ice King is in bed solving a puzzle and mumbling when his doorbell rings and goes to the front door]

Ice King: [Singing] Who is it? [Starts shooting ice lightning] Zap zap zap zap zap zap zap! [Sees a can on the ground] Ooh, someone left me a gift. Peanut brittle? But I'm on a diet. [Shakes can, snickers and opens the can; Jake pops out and takes his crown]

Jake: Should have stuck to your diet!

Ice King: [Throws can on the ground] Oahh! Finn, you have destroyed my faith in canned peanut brittle! Zap! [Nothing happens] Oh, no, my crown has all my powers in it!

Finn: [Tackles Ice King with a giant wrapper strip] Wrap attack!

[Jake is holding Ice King, who is bound, gagged, and struggling]

Jake: [In baby talk] How about I swaddle you up like a sweet baby.

[Jake wraps the Ice King up even more, who struggles all the more]

Finn: We finally captured the Ice King!

Jake: [With Ice King tied to his back] Why'd we do this again?

Finn: Princess explained it all when she sent us on the mission, remember?

[Flashback to the Tree Fort where Finn and Jake are talking to Bonnie via hologram with a very tired Y/n next to her.]

Bonnie: Go capture the Ice King, and bring him to me. Y/n will be joining you.

Y/n: Yay.....

[Back in the present]

Jake: Hmm... That didn't really explain anything.

Finn: I'm sure she's got a good reason.

Y/n: Well this was way easier then I thought.... thank god... I'm in no mood to fight today... Jake carry me back, too tired.

[Y/n passes out on top of Jake who makes space for him.]

[In a dark and gloomy Candy Kingdom]

[Finn and Jake with the Ice King walk into the gloomy, fog covered streets and now more awake Y/n.]

Finn: Where is everybody?

Jake: Yeah, this place is deserted, except for that guy.

Y/n: Oh I know who that is.

[Bonnie in a beak doctor mask comes walking towards them spraying fumigation gas]

Bonnie: Ich bin hier, Finn. ("I'm in here, Finn.")

[Finn and Jake scream; Bonnie takes off her mask and reveals herself]

Y/n: Hallo Bonnie, wir haben den Ice King bekommen, den du gefragt hast. ("Hi Bonnie, we got the Ice King liked you asked.")

[Jake shows Ice King, who mumbles, and Bonnie smiles]

Finn: So, what did the Ice King do to—

Bonnie: [cutting him off] Ah-bababap! No time! Now quickly, with me!

[They go to Princess Bubblegum's castle and walk up to a wall]

Bonnie: Ttubllaw!

[Stone face appears on the wall]

Stonesy: What's the password?

[Y/n and Bonnie each squeeze one of his cheeks.]

Stonesy: What's the password?

Finn/Jake: Secret door!

Bonnie: This stairway leads to the dungeon where we'll toss that lousy Ice King!

Finn: What awful thing did he do to get tossed in there?

Y/n: Trust me, it's for the best.

Bonnie: Chhh, he didn't do anything. Not a thing.

Finn: Wha?

Bonnie: It's a long story, Finn. You see, the Ice King...

Manfried: [Over an intercom] Princess Bubblegum, you're needed at once in the Grand Hall. Y/n L/n is needed as well.

Y/n: God damnit...

Bonnie: No! I need more time! [Flips over a table]

Manfried: [Hanging over on a tree with a bullhorn] Gosh, I'm sorry.

Bonnie: Alright, alright, we have to go. You two just guard the Ice King until we return [Creepily] and be prepared to make him howl with pain.

Y/n: And make sure to wear gloves, howling with pain sometimes gets very... messy.

Finn: You got it, princess,, bro!

[They go to the dungeon, an owl flies overhead as Finn, Jake, and Ice King stand around a table]

Ice King: Oh, this is a total rook!

Jake: Settle down, prisoner! We gotta record your belongings. One magical crown, [Whispers to Finn] probably stolen.

Ice King: I didn't steal it! I made that item! ...Made it with the magic that I stole! So hand it over, or I'll strike menacing poses at you! [Starts striking poses and Finn sprays him with a hose]

Finn: Cool it, inmate! 

[The water begins to whip Ice King]

[Ice King is in a jail cell with only two bars]

Ice King: These bars can't hold me forever! Hey there's only like two of 'em. You fools have no business guarding prisoners.

[Finn and Jake are putting on helmets]

Finn: Oh, yeah?! Well how 'bout these helmets we found? And we got the Oculus of Rehabilitation!

Ice King: Hmm?

[Ice King looks up and there is a giant eye looking at him]

Oculus: Be better!

Finn: And the shelf of penitence!

[Ice King's crown is on a shelf sobbing with water coming from under it]

Ice King's crown: [Sobbing] I'm sorry...I'm so sorry...

Ice King: How about you just hand me my crown. I'll create some ice bars.

Jake: [Running with the crown] Okay!

Finn: No, Jake! It's a trick.

Ice King: I'm toying with you, ha ha, psychologically. [laughs]

[Finn and Jake have built a full set of bars for the jail cell]

Finn: Finished!Ice King: So what am I being charged with?

Finn: Umm...Jake: Five counts of jerkateering. Ha!

Finn: Yeah, what does it matter?

Ice King: Gah! Of course it matters! The way things work is first, I transgress your meaningless rules and then you maliciously persecute me!

Finn: That makes sense. You do bad stuff, we punish you.

Ice King: [Pokes Finn's face] Fool! You have disrupted that order, for—are you ready for this?—I have committed no recent crime!

Finn: Really? Umm...

Ice King: [Laughs] I'm rockin' your worldview!

Finn: Jake, he is starting to convince me we're doing a bad thing.

Jake: Dude, [Licks him] be calmed by my saliva and think of all the terrible things he's done.

Finn: Yeah... yeah! You're still a jerk that deserves to be in jail.

Ice King: Oh, yeah? You know who really deserves to be in jail? I will show you the true jerks! [Pulls out a mirrored covered with a blanket behind his jail cell bunk bed] Behold! [Lifts the blank off the mirror but in doing so extinguish the candle in the cell]

Finn: Uhh, it's too dark.

Ice King: Behold! [Brings the mirror into the light but it shatters at the bottom when he slams it on the floor] Wha, Behold! [Holds it in the air but it falls apart, Ice King groans and gasps and walks up to the cell bars with a mirror piece in his hand and puts it in Finn and Jake's faces] Behold the true jerks!

Finn: The jerks are us? Jake, am I going crazy? It seems like the Ice King is right about this. But if he's in the right, that means we're in...

Jake: The Candy Kingdom!

Finn: No, it means much, much worse.[Turns to the jail cell where Ice King is in bed and opens the door]

Finn: On your feet.

Ice King: [Gets out of bed] Is it time for my hour in the yard, boss?

Finn: No, we're letting you go. We decided that it's wrong to imprison you.

Ice King: This is a trick, huh?

Finn: Get out of here before I change my mind!

Ice King: [Walking out of the cell] There must be someone waiting outside to beat me. Ooh, is that my crown over there? [Goes offscreen]

Jake: [Sighs] I'm glad that's all taken care of.

Finn: No, quite yet.[Finn goes into the cell and pull Jake inside with him and closes the door]

Jake: Awww...

Finn: Sorry, but since we're the bad guys this time, we gotta go to jail.

Jake: This sucks..

Ice King: Hey![Finn shrieks]

Ice King: Get out of my room!

Finn: You're still he— [stutters] ...Just get out of here, man!

Ice King: So, you're really breaking me out?

Finn: Like I said, it's wrong to imprison you.

Ice King: [Tearing up] You mean, you believe me? Oh, can it be? Has all the hatred between us transmuted into something more? A friendship? A best friendship. [Sticks out fist for a fist tap] Knucks? [Finn slaps his fist away] Oh, ho ho, slaps in disgust, eh? Let's call them "Slappy D's"! Okay, see you later, my bosoms!

Finn: I am no man's bosom.

Ice King: Cast "Detect Secret Door"! [He shoots a magic blast and a tunnel opens under the stairway] Success! [Runs away into the tunnel] Wa ha ha ha!

[Just after he leaves, Bonnie and Y/n pop out of a tunnel on the floor]

Bonnie: Sorry for the delay.

Y/n: Took us a bit longer then we thought.

Jake: Man, there are a lot of secret door around here.

Bonnie: [Puts on pink iron gloves] And now, Ice King, prepare to howl with [Sees he's gone] pain?

Y/n: [picks up a hammer off the table] I say we start with the coc- [notices he's gone] where is he?

Finn: Wow, their so proud we did the right thing, they almost looks enraged.

Bonnie: [Takes off the gloves] Where is the Ice King?

Y/n: [sets down the hammer] Explain now idiots!

[Outside Ice King is flying away]

Ice King: Finally! Freedom and friends FOREVER!!!

[Back in the dungeon]

Bonnie/Y/n: What... have... you... DONE?!?! [Bonnie flips over a table and snarls while Y/n uses the hammer and smashes the ground.]

Finn: What have we done?

[The cell door opens and Bonnie grabs Finn and Y/n grabs Jake]

Bonnie/Y/n: I'LL SHOW YOU. [Carries them away]

[In the Grand Hall, Bonnie and Y/n unveil a curtain]

Finn: AHHH!!!

[The room is full of Candy People, covered in ice and lying on cots, sick and spreading ice to other Candy People]

Starchie: Heah, even old Starchie's sick.

Bonnie: A plague of Freezer Burn Flu.

Finn: Ice King did this?

Y/n: Yes and No.

[Flashback]

[In the Candy Kingdom]

Bonnie: [Narrating] It happened 3 days ago.

[Ice King flies overhead]

Ice King: Hey, hey, Princess, check out my new trick! [Starts rubbing flakes out of his beard] It's snowing it's snowing for you!

[Snow falls on the kingdom as the Candy People play in it]

Y/n: [Narrating] We don't think he was trying to spread disease, but soon the entire kingdom was infect by his beard flakes.

[Candy People turn blue and shiver, Bonnie is in her room reading while she is sitting on Y/n's lap.]

Bonnie: [Narrating] Through our research, we quickly discovered that the only two ways to cure my people was to obtain the pained howls of the Ice King himself or get Y/n to heal everyone with his Phoenix Healing.

Y/n: [Narrating] But the case was so severe that as soon as I healed someone they got sick right away again. It nearly drained me completly dry of my magic so we decided on the howls.

[In the Ice Kingdom, Bonnie is riding Lady Rainicorn with a sound device over a mountain Ice King is on top of. Y/n is next to Bonnie.]

Y/n: [Narrating] But when we pleaded with him directly...

Bonnie: Please, I beseech your aid. In the name of common decency!

Ice King: So let me get this straight... You're hitting on me.

Y/n: OH HELL NO SHE AIN'T YOU OLD FOOL!

Lady Rainicorn: 으으, 웃기시네! 너는 우리 공주님과 판결 상대도 안 될 그런 가치없는 놈이야! ("Are you joking? You are not even worth my Lady's and Lord's disdain.")

Ice King: I think I heard the word "Virile" in there. Oh, she is definitely hitting on me.

Y/n: No!

Bonnie: No!

Lady Rainicorn: 말도 안 돼! ("No!")

Ice King: Be gone, you biddies!

Bonnie: [Narrating] He had his chance to help and he did nothing!

Ice King: Oh, my gosh, she came to me this time. Don't know why she had to bring her boy toy with her.

Y/n: I FUCKING HEARD THAT YOU OLD PERVERT!

[Flashback ends]

Bonnie: We had no choice but to try and take his wails by force.

Jake: By getting us to beat the tar out of him.

Finn: I can't just beat up the Ice King for nothing. That's against my alignment.

Bonnie: I know, I know. You're right. [Starts to cry]

[Y/n quickly wraps Bonnie in a side hug and she cries into his chest.]

Finn: But I'll get him to give up those howls. Voluntarily. I swear it.

Bonnie: Oh, thank you, Finn. I... [Cries]

Y/n: Thanks Little Bro. I'd go with you but my Aura is slowing down the process as much as it can.

Finn: It's alright Bro, we got this.

Y/n: Thanks, I mean it.

[In the Ice Kingdom, Finn and Jake are running towards the Ice King's Castle]

Jake: Dude, how are we gonna get those howls?

Finn: Oh, I gotta plan to trick him, but you won't like it.

Jake: That sounds ominous. I don't like it!

[They enter the castle]

Finn: Ice King, come forth!

Ice King: I'm coming forth! Hee hee, is that the voice of friendship I hear? [Walks in the room with a board game] So, are you fellas ready for game night?

Finn: Game night? Well, that's weird.

Ice King: What? Why?

Finn: You do know how friends act, right? You've had friends before.

Ice King: I... yes?

Finn: Yeah, so you know how friends are always howling in pain for each other.

Ice King: Yeah... right! Everyone knows that! [Laughs awkwardly]

Finn: [Holds up the sound device] Will you howl for me, pal?

Ice King: Oooh, of course, friend. Awoo-hehehehe! Oh, I've got the sillies! I couldn't possibly without giggling uncontrollably. I'm just so giddy about you being here! [Laughs, falls on his back and grabs the bottom of his cloak and rocks back and forth] I'm a banana! [Laughs] Don't slip on me!

[A shrunken Jake jumps on Finn's shoulder]

Jake: We're out of options. Let's just beat it out of him.

Finn: No, Jake! We...

Ice King: [Gets up] Wait a sec, there's a bug on you, friend. Smack! [Smacks Jake and in doing so hits Finn]

Finn: Grrr... Biscuits, now's my chance!

Ice King: [Shuffling through the board game, picks up a game piece] You know, I carved these game pieces from my own teeth.

Finn: Boo hoo, boo hoo, boo hoo, boo hoo...

Ice King: Huh? Crying?!

Finn: Boo hoo. You hit me, Ice King. I don't think I could live any more knowing my best bosom hit me.

Ice King: I was only saving you from poo poo palms!

Finn: I'm dying because I know you care not for me. [Plays dead]

Ice King: No! No, my...my bosom! What hath I done?! My friend! [Picks up Finn] My only friend.

Jake: Hey, what about me?

Ice King: Why?! Why?! WHY?!!!

[The scream is so loud it reaches the Candy Kingdom, where the ice falls off the sickened Candy People]

Starchie: Starchie's feeling healthy again! [Grow muscles] A bit too healthy if you ask me.

Y/n: Damn Starchie, you are ripped as hell now.

[More Candy People are cured]

Bonnie: They're all getting better! Finn and Jake did it! Ich bin so glücklich, ich könnte, ich könnte... ("I'm so happy, I could, I could...") [Almost flips over a cot but Y/n catches her.]

Y/n: Sei vorsichtig Schatz. Sie haben es geschafft. Ich bin stolz auf sie. ("Be careful Honey. They did it. I'm proud of them.")

[Back in the Ice Kingdom]

Ice King: WHY?!!!... Ah, well. Gunter! Dispose of Finn's carcass.

[Finn pops up]

Finn: [Sad] Harumph.

Jake: Good job! Those wails must have reached all the way to...

Finn: Did you see how fast he dropped my lifeless body? That's just mean.

Jake: Finn, if I came across your lifeless body, I'd clasp you dramatically for a kajillion years.

Finn: Thanks, man.

Jake: [Grows] Hey, why wait?! Play dead, Finn!

[Finn plays dead and jumps into Jake's arms and Jake hops away on the mountain tops toward the Candy Kingdom]

Jake: Why?! Heh heh heh heh. Why?! Heh heh heh heh. Why?!

[The episode ends with the Adventure Time logo]

Finn & Jake: Adventure time!

(Sorry this episode isn't very Y/n focused. I honestly wanted to include this mainly so I could have an excuse for Y/n to speak German and the joke I made with the hammer. Also seeing Y/n angry at Finn and Jake is funny and him being angry at Ice King for hitting on his girl.)