Author's Note: Here's the finished chapter. Got some really good work done while stuck at home cuz of, well, you know. Enjoy!

CHAPTER THREE: Castle And Dragon

We open with our heroes returning to Petalburg triumphantly, having successfully faced the trials of Shwonk Fortress and with the keys to the Petalburg Castle Pipeline in hand. As Koops lead the rest of them back to his place for some well deserved rest before they make their assault on the castle, they were approached by a koopa girl.

She approached Koops and said, "Oh, there you are! I've been looking everywhere for you, Koops! There are rumors that you're planning to fight Hooktail! Can you believe that?"

"Oh, uh..." Koops started, nervously, "Hi, Koopie-koo. I guess I forgot to tell you... I, uh, am planning to fight Hooktail."

"What? Why?! She'll kill you!" the koopa girl cried.

"Oh, have some faith in me, I'm not that bad a fighter!" Koops responded. "Plus, I've got help!" He motioned toward his new friends, "This is Finn the Human, you know, the hero of the Candy Kingdom? He's going to help me avenge my father! Or, uh, more accurately, I'm going to help him rid our village of the scourge of Hooktail..."

Finn waved, "'Sup?"

Koopie-koo's expression darkened. "You're still going on about avenging your father? It's been ten years, Koops!"

"I need to do this! Not just for myself, but for the entire village!" Koops shouted.

"FINE!" Koopie-koo shouted back, "Go and get yourself killed over some stupid desire to prove yourself! You stubborn koopa!" And then she ran off, crying.

There was a brief, awkward pause.

"Welp," said Koops, "That went rather well, I think." He turned to his new friends and added, "So, uh, that was my girlfriend. Possible emphasis on was."

"Big oof, bro," said Jake.

Koops waved him off, saying, "I'm sure it'll be fine. We'll have a nice rest, and then we'll storm the castle, slay the dragon, and we'll all live happily ever after."

"Well, you will, anyway," said Finn, "After we deal with the dragon, I've still got like six more Crystal Stars to collect." He suddenly snapped his fingers. "Aw, mess! I just remembered why I'm doing this in the first place! You wouldn't happen to know if a rad lady by the name of Princess Bubblegum came through this town at some point, would you?"

Koops thought for a moment, before answering, "Nope. I can't say I've seen the princess of the Candy Kingdom anywhere in our little town." After another pause. he added, "Why? What would she be doing out here anyway?"

Goombella decided to answer that question, saying "See, it's those Crystal Stars that Finn just mentioned. The Candy Princess somehow got her hands on a map that can lead to them, and we've kind of come to the conclusion that she started looking for them without us. Or the map. Or anything more than the rumor that a Crystal Star might be in this general area."

"You know, when you put it like that, it does seem like one heck of a stretch," said Finn.

"Whatever," said Jake, "I'm tired, let's get some shut-eye and figure this out in the morning."

"Dude, you've been in my backpack since we left for Shwonk Fortress," Finn said angrily, "You have no right to be so tired."

"The rest of us do, however, so let's hurry up," Goombella added, "Before any of us start to get cranky."

They all agreed that was great idea, so they continued on their way. But before they got very far, suddenly, BMO popped out of Finn's backpack, shouting "You've got mail!"

"Wha-? BMO?! How long have you been in there?" Finn asked.

"How did I not notice you in there?" Jake asked.

"It is a secret to everyone," the little robot responded. "Anyway, e-mail from Princess Bubblegum! It seems important, so I thought I should tell you now."

"Let's see it, then!" Finn said, pulling BMO from his backpack.

This is an automatic message. If you have received it, it means I was unable to prevent it from being sent. I have set this up as a precaution in case something happens to me during my goodwill trip. Of course, I will ask that you don't worry about me. I can take care of myself, and I shall attempt to get in touch with you through other means, if possible.

Princess Bubblegum

P.S. I recently sent you something that is supposed to be a treasure map. If you do receive this message, then my disappearance is likely connected to it. Please pursue all potential leads regarding the "treasure", and I shall, as previously stated, work on finding alternate means of contacting you. Best of luck!

"Welp, I guess she was actually kidnapped, then," said Finn. "She says not to worry about her, though, and to keep doing what we're doing."

"Good to know," said Jake, " now let's all get some sleep already!"

The next morning, they all got up, had a hearty breakfast ("The most important meal of the day," Jake insisted), and made their final preparations for the assault on Petalburg Castle.

They left the town after a quick stop at Mayor Kroop's house to confirm how they were supposed to use the keys, but barely got more than a few steps when Koopie-koo appeared.

Koops glared at her. "I've made up my mind, Koopie. You're not going to make me change it," he told her.

"No, I understand that. I gave it some thought, and I decided that, if this is something you feel you need to do, then you should do it," she replied. "Just, promise me you'll come back alive?"

"Of course! I'm a tough koopa, and I've got the hero of the candy kingdom backing me up-" ("More like he's backing us up..." Jake muttered.) "So you can trust me, that dragon is going down!"

"Okay. Good." Koopie-koo's expression turned dark, "Because if you die, I will find your ghost and double-kill you myself."

There was a beat, and then Koops responded, "That's fair."

Koopie-koo smiled in that distressingly sweet way a yandere would. "I'm glad we have an understanding," she said, as she walked back to town. As she passed by Finn, she whispered to him, "Seriosuly though, make sure he doesn't get himself killed."

Finn gave her a thumbs-up. "Will do," he whispered back.

Jake looked over at Koops, "Your girlfriend is scary when she wants to be," he said.

Koops let out a nervous chuckle, "Yeah, she can get like that. It's, uh, what I like about her, though."

Goombella clapped her hands and declared, "Okay! Who's up for storming that castle?"

The others nodded in agreement, and they headed off to the pipeline entrance.

Opening the pipeline was as easy as Kroop had made it sound, and the group made their way into the main hall of the castle. It was littered with the skeletons of dead koopas.

"Ugh... I really didn't need to see this," said Koops. " One of these skeletons is probably my dad's..." He pushed that thought from his mind. "Let's get out of here, please."

So they pressed onward, eventually finding themselves in a room absolutely filled with koopa skeletons.

"Globdammit, really?!" Koops shouted. Suddenly, the piles of bones began to rattle, and an eerie voice declared, "This room is our grave! Leave now, or it will be yours as well!"

"Look, we're here to kill Hooktail and probably avenge you guys, can't you just let us though?" Finn asked. Skeletons began rising from the piles and charging toward them.

"Guess not," Finn said with a sigh as he started to cut through the attacking horde.

"Finn's taking this rather well," Goombella mused.

"We are seasoned adventurers, after all," Jake added, "This is nothing compared to some of the stuff we've seen."

After a while, they all got rather tired of smashing up the attacking skeletons. "They just keep coming!" Finn cried as he cut down another. "And I swear I've killed some of them multiple times!"

Suddenly, Koops noticed something. A red koopa skeletons in the back of the horde that seemed to be directing things. He launched himself through to crowd, knocking aside several other skeletons before crashing full force into his target, smashing it to pieces. As soon as he had done so, the rest of the skeletons also fell apart, and the room grew quiet.

A moment passed with nothing happening.

Everyone breathed a sigh of relief. "Glad that's over," said Finn, wiping sweat from his forehead. "Nice work taking down that sub-boss, Koops."

Koops just grinned, "No problem, my dude."

The group proceeded carefully onward, finding two doors at the end of the next hallway. Naturally, one of them was locked. "Any bets the key's hidden in a puzzle in the other room?" Goombella joked.

"There's probably something guarding it, too," Finn said, his hand already hovering over the hilt of his sword as he slowly opened the unlocked door.

The room beyond was some sort of storage room, with crates of all sizes. And some of them were open. And, someone was still digging through one of the opened crates.

It was a small, mousey girl wearing a red catsuit. "Mousey" was perhaps a bit too apt a description, as she was a mouse. (Which made her choice of attire somewhat ironic...) Upon hearing the door opening, she turned, startled. "Oh, thank gob," she declared when she saw Finn, "I was worried one of those skeleton koopas had remembered how doors work."

"Who are you? And what are you doing here?" Finn asked.

"My name is Ms. Mowz, and I'm here for the same reason you are, I would guess," she replied.

"You're here for the Crystal Star?" Koops asked without thinking.

Ms. Mowz smirked, "Goodness, a Crystal Star, you say? I had no idea a treasure like that was here. Perhaps you just said something you shouldn't have?"

"Ah, poop," said Koops, quietly. "Well, uh, you can't have it! We, uh, called dibs? Is that a thing you can do?"

Ms. Mowz chuckled, "Don't worry, I'm not interested in 'legendary treasures', I'm just a badge collector. And it just so happens I've found everything I was looking for here." She walked up to Finn, and added, "Of course, I do believe I've found one last thing I just have to steal before I go..."

"And that would b-" Finn started to ask, before the mouse girl pulled him into a kiss.

"HEY! Y-you - you can't just- what?!" Goombella cried.

"Oh, I'm sorry," Ms. Mowz said, clearly not sorry, "have you 'called dibs' on that treasure, too?"

Goombella blushed, "Uh, um, that is, I..."

Ms. Mowz laughed, "Oh you are just too precious." She turned back to Finn and handed him a badge and a key. "A legendary treasure would probably be in the dragon's personal hoard. You'll need these more than I do if you're seriously planning to fight it." She then hopped up to a conveniently open window, and with one last salute to them, said "I hope we meet again, hero!" And then she dove out.

Finn stood there, dumbstruck for a moment. "Dude, I-"

"Finn, I swear to glob, if you're about to say 'I think I have a crush,' don't," Jake said before he could finish.

Finn cleared his throat, "Right, okay."

"So, what, exactly, does that badge do?" Koops asked as they proceeded further into the castle.

"Heck if I know, I tap it and it just makes a chirping noise," Finn replied. He gave the badge a quick tap to demonstrate. "I think it's supposed to be a cricket?"

"Sounds more like a frog to me," said Goombella.

"Well, whatever it's supposed to sound like, I'm not sure how it's supposed to help us defeat Hooktail," said Finn.

After some more boring walking, the heroes finally reached Hooktail's personal chamber.

"Who dares disturb the Mighty Hooktail? More of those costumed jerks?" a booming voice called out. Moments later, a massive red dragon rose out of the pile of treasure in the center of the chamber.

Koops stepped forward. " Hello, my name is Koops. You killed my father, prepare to die!"

Hooktail studied the young turtle for a moment. "It's possible," she eventually responded, "I've killed a lot of people. You don't expect me to have kept track of them all, do you?"

"That doesn't matter!" Koops shouted, "What matters is we're going to take you down!"

Hooktail scoffed, "Many have tried, and none have succeeded. What makes you think you'll be any different?"

"Because we have this!" Finn shouted, and he tapped the badge Ms. Mowz had given him. The chirping noise echoed through the chamber, and Hooktail let out a retch.

"Urp! Was that a cricket? Or perhaps a frog? Urgh, I can't stand crickets or frogs. Oh, I get sick just thinking about them!" Hooktail cried.

Taking advantage of her momentary distraction, Koops launched himself at the dragon, hitting her squarely in the chest, and, to everyone's surprise, knocking her backwards.

"Agh, it's even worse! Thinking about that sound has made me so weak! Please, spare me! I'll give you as much gold as you can carry!" Hooktail pleaded.

"Or we could just finish you off and take it all," Koops responded.

"Is there anything you might want from me?" Hooktail asked.

"Actually, there is," said Koops, "I want my father back!" And with that, he launched himself at Hooktail again, and delivering the killing blow. And with her dying breath, Hooktail puked up a blue koopa shell.

Koops stared at the shell for a moment, and then started to tear up. "T-that shell, it's my dad's shell..." he said. "Hooktail gave me what I wanted. Heh."

Suddenly, the shell began to shake, and an old koopa with bushy eyebrows popped out of it. "Freedom! Daylight! Oh, I thought I'd never see the day! Goodness, how long has it been?" the old turtle said to nobody in particular.

"Dad?!" Koops cried.

The old turtle turned toward Koops. "Koops?" he asked. Koops nodded. The old koopa rushed over and embraced his son. "My boy! You saved me! I don't know how, but who cares?"

"I'm kinda jealous," said Finn, "Koops gets a touching reunion with his dad, but when I try to rescue my dad, the jerk ditches me pretty much immediately."

Goombella starts to ask what he meant, only to be cut off, "No, I do not want to talk about it."

"It's a very sore subject," Jake whispers to her.

Koops led his father over to the rest of the group. "Guys, this is my dad, Koopley."

"Thank you for helping my son in this endeavor," said Koopley.

"Now the only thing left is to find the Crystal Star," said Goombella.

"Crystal Star, you say? Would it perchance be something like this?" Koopley asked, presenting the group with a white crystal cut in the shape of a star and radiating a strong magical aura. "I found it in Hooktail's belly, of all places, and I do believe its magic is what kept me alive all this time." He presented the star to Finn. "However, if it's something you need, then you can have it."

"Thank you, sir," Finn said, placing his hand on the star. And suddenly, there was an explosion of colors, and Finn felt a rush of power. "I, uh, think I need to lie down for a moment," he said when it subsided.

"Honestly, we could all use a rest after all that," said Koops. And so, our heroes returned triumphantly to Petalburg.

END OF CHAPTER

AN: So, I'm just gonna come out and say it, I am pretty much cherry-picking Adventure Time lore for this story. I've mentioned Finn's dad, and his mom might also show up somewhere, but I don't care about the details of their existence.

Next up is the Peach Interlude, or Bubblegum Interlude, in this case. Expect it to be short.