In the Candy Kingdom, Jake was playfully chasing Lady Rainicorn.

Jake: Yeah, you think you're pretty way up there but I can get you!

Using his powers, he stretches to be on Lady's level.

Lady Rainicorn: (Sure, catch me if you can!)
*Translation from Korean.

Meanwhile, Max, Finn and Princess Bubblegum are in a cemetery with a table full of different chemicals. A crow sat on a nearby branch.

Princess Bubblegum: Alright. Let me just add three more drops of explosive diarrhea.

She adds the explosive diarrhea and a giant cloud shaped like a skull puffs out. Not a good omen.

Finn and Princess Bubblegum: Oooo...

Finn: Hey Princess Bubblegum, when we bring the dead back to life, will it be filled with worms?

Max shivered at the very thought of that. The pale skinned male crouched down and held the side of the table. He shivered nervously.

Princess Bubblegum looked down at him and smiled at him. She rubbed his head.

Princess Bubblegum: No. If my decorpsinator serum works, all the dead Candy People will look as young and healthy as you do.

Finn did a "Tarzan-yell" while hitting his hands against his chest.

Max stammers slightly, his cheeks flushing with embarrassment, and he glances down at his feet.

Max: T-that's good. I think.

He fidgets with his hands, unsure of how to react to Finn's enthusiastic antics but appreciative of the compliment.

Princess Bubblegum offers a warm and reassuring smile to Max, recognizing his nervousness.

Princess Bubblegum: Don't worry, Max. It's a positive thing.

Princess Bubblegum looked over at Finn

Princess Bubblegum: Pick up that platter, Finn.

Finn picks up a serving platter and open the lid, revealing a Candy Person corpse.

Finn: Old Mr. Cream Puff?

Princess Bubblegum giggled.

Princess Bubblegum: We used to date.

She the applied the serum. Mr. Cream Puff's corpse starts to glow and overflow with the fizzing serum. Max stayed close and hid behind Princess Bubblegum.

Finn: Something's happening! Come on, come on...

Princess Bubblegum: Work.

That was when the zombie Mr. Cream Puff arises and moans.

Max: Is that supposed to happen?

Zombie Mr. Cream Puff: Sugar!

Zombie Mr. Cream Puff then squirts serum out of his eyes and mouth.

Finn, Max, and Princess Bubblegum: Ew!

Zombie Mr. Cream Puff leaps into a giant test tube. The test tube falls and infects the whole cemetery. Zombie Candy People begin to arise from their graves.

Max: I don't this this is supposed to be happening!

Finn: What do you mean, the decorpsinator serum is working?

Princess Bubblegum: No, Max is right. They're not coming back to life--they're still dead! The decorpsinator serum--it's incomplete!

She rubs the head of a candy person that looks like a love heart.

The Zombie Love Heart started lashing out at Princess Bubblegum. Max nervously pulled Princess Bubblegum away from the zombie as Finn then punched the zombie.

Princess Bubblegum: Oh, this is really bad. They're going to be attracted to the Candy Kingdom!

Finn: Why?

Princess Bubblegum: Because the Candy People are made of sugar, ya ding dong!

Zombie Mr Cream Puff jumped on Max.

Zombie Mr Cream Puff: Gimme some sugar, baby.

Max freaked out and started jumping up and down frantically trying to get it off.

Finn: Chew on this!

Finn kicked the zombie off.

Finn: Max? You ok?

Max: Ya ya ya...I think so.

Princess Bubblegum: Quickly, to the kingdom!

They ran out of the cemetery. Princess Bubblegum ran to the top of her castle, and started ringing a large bell.

Princess Bubblegum: All citizens of the Candy Kingdom! Report to the palace, immediately!

Candy People mumble in confusion and walk to the palace

Jake: Whoa!

Jake and Lady go off to the palace. Princess Bubblegum notices the zombies slowly leaving the cemetery. She grew more worried.

Princess Bubblegum: Hurry, sweet citizens.

Finn was helping everyone get inside.

Finn: Alright, you heard the princess, everyone in! Alright, no pushing, come on!

Jake: Dude, what's up?

Finn: The princess will explain everything. Tree Trunks, get those hot buns in here, girl.

Tree Trunks carried a basket of hot buns inside.

Tree Trunks: Oh, I hope it's not bad news.

Princess Bubblegum and Finn close the door

Finn: Did we get everyone?

Manfried: All present and accounted for.

Finn: Thanks, Manfried.

Manfried: You're welcome.

Princess Bubblegum: Citizens, we are assembled here in the candy foyer for a momentous announcement. Tonight we are all going to have...a slumber party!

Max: Wait? What?

The crowd cheered and confetti appeared out of nowhere.

Max gulped nervously. He was terrible at being at social events.

Finn: What?!? Wait! What about the zom--?!

Princess Bubblegum covered his mouth

Princess Bubblegum: Go ahead and start partying.

Finn: But, Princess, the Undead-

Princess Bubblegum took Finn and Max to her lab.

Princess Bubblegum: Finn, Max, the Candy People can't know about the zombies.

Finn: Wha?!

Max: Why not?

Princess Bubblegum: If they knew, they would flip out.

Finn: What do you mean "flip out"?

Princess Bubblegum: I mean they would flip out.

[Flashback.]

Starchy: Princess? It's me, Starchy the gravedigger. I brought you a larger corpse shovel. Oh, Princess? Well, I'll just wait for you here, then. By the mausoleum. With my back turned. And my defenses lowered.

As Starchy does so, Candy Zombie comes out of the mausoleum and goes up to Starchy, Starchy starts to scream and gasp and then... KABOOM!!! He explodes in a flash of light.

[Flashback]

Finn: Candy People explode when they get scared?!

Max: Oh dear.

Princess Bubblegum: Not telling the Candy People about the zombies is so important that you need to promise, Royal Promise, not to let anyone find out about the zombies, ever.

Finn: Okay, sure.

Princess Bubblegum: No, Finn. You have to Royal Promise.

Finn: Yes, I Royal Promise.

Princess Bubblegum: Now I must cloister myself in the lab and finish the equation to my decorpsinator serum. You keep the candy folk distracted and ignorant. Can you do that?

Finn: Yes, your highness.

Princess Bubblegum's request hangs heavily in the air as Max nods, though his nervousness is palpable. He swallows hard, trying to muster the confidence to respond.

Max: Uh, sure, Princess Bubblegum. I'll, um, keep them distracted and...ignorant?

Princess Bubblegum places a reassuring hand on Max's shoulder, sensing his unease.

Princess Bubblegum: Max, I believe in you.

She kissed his forehead.

Max looked up at her nervously and nodded his head gently.

Princess Bubblegum: Good. Don't tell anyone about the zombies. Never ever.

She left the room and entered her lab.

Finn: No, wait. Can I at least tell Jake?

The moment he said that, Jake entered the lab.

Jake: Tell me about what, dude?

Finn: You know, about the outbreak of zom--

Max looked and Finn and immediately began doing hand motions.

Finn: About Max's charades. He's a zombie.

Max immediately stopped. A crow sat on a nearby open window.

Jake: Alright, what's going on?

Finn: Uhh, nothing at all, buddy!

Finn laughed awkwardly and skips into the foyer

Jake: Hey, dude. I think you, Max, and Bubblegum are up to something.

Finn: Ahha ah, what? No, no way.

Max: I can't say anything about it.

Jake: Whoa, you guys are up to something. Is it some sort of prank? Can I get in on it?

Finn: Who wants to play "Truth or Dare"?

Jake: Hmm...

Finn, Max, and Jake sat down with a small group of Candy people to play truth or dare.

Finn: Ok, Chocoberry, you may ask someone to tell a deep truth or a saucy dare.

Chocoberry: Mr. Cupcake, truth or dare?

Mr. Cupcake: Dare.

Chocoberry: I dare you to take off your wrapper.

Everyone goes "Oooh". Max looked uncomfortable. Jake shouldered Finn and Max.

Jake: Hey seriously, guys. I'm your bro. Bros are supposed to tell bros everything all the time. What are you, and Bubblegum up to? Is everything alright?

Max: I'm not allowed to say, security reasons.

Max looked in the direction of a crinkling sound. Mr. Cupcake had shed his wrapper.

Peppermint Butler: I didn't know he was chocolate.

Mr. Cupcake: Jake, truth or dare?

Jake: Truth.

Mr. Cupcake: Do you prefer chocolate or fudge?

Jake: I can't eat chocolate or fudge cause I'm a dog and they'd probably kill me, but hmmmmm probably... neither. Finn! Truth or dare?

Finn: Dare! Haha!

Jake: I dare you... to tell me the truth about what's going on in your mind. What were you, Max, and Bubblegum talking about when you were alone together?

Everybody goes "Oooh".

Finn: Umm, ahh, the truth is, ahhh...

Finn visualizes Princess Bubblegum's face on Jake.

Hallucination of Princess Bubblegum: You promised you wouldn't freakin' tell anyone! Oh, you're so cute, Finn.

Finn: Ahhh... the truth is... that I'd rather play Dodge Socks!

Finn throws a sock a Jake, Princess Bubblegum's face goes away

Jake: I'm not playing dodge socks 'til you stop dodging my questions.

Jack stopped as he sniffs socks.

Jake: Hey...Old Mr. Cream Puff? Isn't he dead?

Max: Technically yes.

Finn: Hey, give me my sock back! Dodge Socks was a bad idea!

Jake: Whoa.

Jake looked at Finn and Max angrily.

Jake: Look dudes, just tell me what's up, cause you are crazier than a cannonball tonight.

Max looks out a window behind Jake and sees the zombies coming.

Max: We can't say anything!! Ok! We just can't say anything. We're not allowed to! We royal promised!

Max said as he was freaking out. It sounded like a mix of 30% of frustration and 70% of panic. Zombie arises by the window behind Jake

Zombie: Sugar!

Finn shuts the shutters. Jane looked at Max in shock. Now he was the one who is a little freaked out.

Jake: Ok ok ok. Calm down. Nobody's working against ya. I get what's up.

Jake looked at Max's left arm, and noticed that black veins seem to be seeping through. He was about to point this out.

Finn: Umm... Hey, you know what time it is?

Jake: Adventure time?

Finn: No, time for Seven Minutes in Heaven! You're first.

Jake: Really?

Finn: Lady Raincorn! In the closet with Jake!

Lady Rainicorn says something in Korean. Finn pushed the two in the closet.

Jake: Okay, okay, alright.

Finn looks out a window, a horde of zombies shouting "Sugar" comes and begins banging on door. Max looked around the room nervously and was trying not to freak out.

Chet: Umm, does anyone else hear that?

Finn: What? Hear what? I, I don't hear anything.

Candy People begin to murmur as they too hear the banging.

Chet: I hear something I don't understand... and it makes me scared!

Max: Me too...

Finn: What? No, Chet. Everybody, wait. What noise? You mean this noise?

Finn turns on a radio and party lights comes on.

Chet: Oh.

Chet laughs

Finn: Yeah! Dance it! Bust it up! Uh! Uh! Uh! Oh!

A zombie comes out of the main door, Finn rushes to the door, grabbing a table

Chocoberry: What is this game you are playing at now, Finn?

Finn barricades the door with the table

Finn: Uhh, it's... Blockado. Haha, the game of barricades. Come on, let's block all the entrances and windows!

Candy People cheer and begin blockading the doors and windows before the zombies can come in. Max began trying to block doors as well. But every time he grabbed something with his left hand, the item he was holding, began to shrivel and break apart.

Max: Bloody hell. Princess bubblegum hurry hurry!

Finn: Alright, this is not a permanent solution. Think Finn, how can you keep everyone from finding out?

Manfried: Find out about what, Finn?

Finn: Manfried, the talking piñata! Your convient appearance gives me a great idea. Everyone, grab a stick! New game! We're gonna smash some piñatas!

Manfried: What?

Finn: Except for you, Manfried.

Manfried: Oh, thank goodness.

Max takes somes strips off of Taffy Girl.

Finn: Now everybody don these blindfolds.

Max: Thank you, Taffy Girl.

Finn runs into the middle of the blindfolded Candy People swinging sticks.

Finn: Alright, everybody, get together. I'm hanging the piñatas...

The zombies burst through the barricades.

Finn: They're all around you. Smash the piñatas!

Finn and the Candy People smash all the zombies.

Finn: Yeah! You guys are on fire!

Max on the other hand was freaking out. As the zombies close in on him, a surge of power wells up within him, and without understanding the full extent of his abilities, Max instinctively releases a blast of ominous darkness.

The blast strikes three of the candy zombies, and the result is catastrophic. They're instantly consumed by the inky void, reduced to nothingness in a flash of black energy. Max stands there, panting, as he watches the eerie aftermath of his attack, a mixture of fear and astonishment on his face.

Max: (breathing heavily) What... What just happened?

Chocoberry smashes a zombie, causing candy to fall out. She kneels down and licks the candy.

Chocoberry: Oh, it is so tasty.

All the Candy Zombies are smashed and the Candy People are eating their candy.

Finn: Yes! We did it! My improbable plan worked!

Jake and Lady come out of the closet

Jake: Whew!

*Lady Rainicorn says something in Korean*

Jake: Seven minutes up yet?

Jake grabs a jelly filled doughnut and eats it, noticing the zombie corpses.

Jake: Whoa!

He runs to Finn.

Jake: What the nuts happened here?!

Finn: Oh, we killed all the zombies that Princess Bubblegum and I raised from the dead.

Jake: Really!?

Time freezes, leaving only Finn and Max moving in the room.

Finn: Jake? What's going on?

Princess Bubblegum enters, unaffected by the freezing.

Princess Bubblegum: What? Huh? Oh, Finn! Did you break your Royal Promise?

Finn: Yeah, but, I mean, all the zombies are dead. The Candy People won't freak out. What's the big deal?

Princess Bubblegum: This is really, really bad, Finn. You can't break Royal Promises. Never, ever, never. No matter what, forever.

Max, overwhelmed by the slumber party, the relentless zombie attack, his newfound powers, and now the inexplicable time freeze, feels a wave of panic wash over him. Without a second thought, he wraps his arms tightly around Princess Bubblegum in a desperate attempt to find some sense of stability amidst the chaos.

Max: (nearly panicking) Princess Bubblegum! This... this is too much! I don't know what's happening!

Princess Bubblegum pats Max's back reassuringly.

Princess Bubblegum: (calmly) It's alright, Max.

She looked down and noticed where Max was holding her outfit, that part of the dress began to slowly wither away.

The room starts shaking

Princess Bubblegum: The Guardians of the Royal Promise are coming for us.

Max: There are Guardians of the Royal Promise?

A hand bursts through the ceiling and grabs Finn, Y/N, Princess Bubblegum and pulls them outside

Finn, Y/N, and Princess Bubblegum: Whoa!

Guardian 1: Finn the Human. You have broken a Royal Promise for which the penalty is trial by fire.

Guardian 2 breathes fire. Max gulped nervously and clasped both his hands.

Finn: That's stupid.

Princess Bubblegum: Wait! He's my friend! Isn't there another option?!

Guardian 1: Yes. Because you care for the promise-breaker, we will give him a less hot trial. You must now answer...

Guardian 2: ...Math questions!

Max: Sounds simple enough.

Finn: Mathematical!

Princess Bubblegum: Finn, you're terrible at math.

Max:...He's gonna die.

Finn: Awww.

Guardian 1: Now, solve this!

Guardian 1 put Finn in front of Guardian 2, who puts up a hologram of an overly complicated math equation.

Finn: Uhh....

Guardian 2: Oh, wait, wait, I thought of a better one.

Guardian 2 replaces the equation with one that says "2+2"

Guardian 1: Yes! Two plus two. Solve it or die.

Finn: Uhh. Four, right?

Guardians laugh

Guardian 1: Oh, correct.

Guardians heads explode and time rewinds, night becomes day, Guardian 2's head comes back and he talks backwards and goes back to sitting and blowing bubbles around the Candy Kingdom.

Finn: What's happening, Princess?

Princess Bubblegum: You've defeated the broken royal promise! The Gumball Guardians are resetting!

Guardian 1 drops Finn, Y/N, and Princess Bubblegum, who teleport back to Princess Bubblegum's lab.

Finn: Slamacow! That was tops! Who's not good at math? I was all "Four!"

Princess Bubblegum: Four, four... Four, four, four... That's it! The answer was so simple, I was too smart to see it!

Max: Is that how it works?

Princess Bubblegum: '4' is the last figure I need to perfect my decorpsinator serum.

In the foyer, Princess Bubblegum pours the serum on a zombie.

Revived Zombie: Golly!

Finn and Princess Bubblegum pour the serum on all the zombies.

Finn: Woohoo! Yeah!

Jake: This is messed up, but sweet.

*Lady Rainicorn says something in Korean*

Finn, Y/N, Princess Bubblegum revive more Candy Zombies.

Candy Person 1: Uncle Chewy!

Candy Person 2: Grandma!

Ice Cream Lady: All of our dead relatives!

Jake: Starchy!

Starchy: Mornin'.

Jake walked to Finn.

Jake: Man, you broke a Royal Promise? You're nuts. All you had to do is say that it was a royal secret. I know what's up.

Jake walks away from Finn.

Princess Bubblegum: I hope you grasp the full consequences of breaking promises.

Finn: Heck yeah! If I break a Royal Promise, I get to fight zombies, throw slumber parties, awake Gumball Guardians and... and...

Princess Bubblegum: Alright, alright.

Finn: And reverse death itself!

Princess Bubblegum: Oh, you are adorable. But keep your promises, okay?

Finn: I will, Princess.

Max looked at the part of the Princess's that his touched, and noticed that it looked at little shriveled.

The crow, perched on a nearby tree branch, observes this extraordinary event with keen interest. Its dark eyes widen in astonishment as Max's abilities come to life before its eyes. With a startled caw, the crow takes flight, its wings beating frantically as it soars toward the horizon.

Meanwhile, at a dark and foreboding castle, perched high on a craggy hill, Plague, the master of diseases and toxins, is deep in thought at his desk. Papers and vials are scattered about, a testament to his sinister experiments. Suddenly, the crow lands on his desk, its feathers ruffled from its hasty flight.

Plague, intrigued by the crow's arrival, leans forward and regards it with a calculating gaze. He extends a gloved hand, and the crow hops closer, as if bearing a message. Plague carefully removes a small, folded note that the crow has carried.

Unfolding the note, Plague's eyes narrow as he reads its contents, his lips curling into a sinister smile.

Plague, with the urgency of the news weighing heavily on him, quickly leaves his castle and journeys to Landor's lair. He finds Landor in a dimly lit chamber, surrounded by strange machinery and arcane symbols.

Plague: (breathing heavily) Landor, I have important news. The boy, Max... his powers are starting to emerge.

Landor, seated on a sinister-looking throne, turns his attention toward Plague with a sinister grin.

Landor: (calmly) Finally.