The Morrow dropped them off on the balcony outside Princess Bubblegum's bedroom. Peppermint Butler scurried over as the princess strode into the room.
"Your Majesty, what's wrong?"
"There's a new monster on the loose," she said, starting to gather books from her shelves. "Make up a batch of tea. We're going to have to go through my library to find what that creature was. I had Beemo take a picture—"
"Don't bother," Marceline interrupted. She still floated in the doorway, staring out into the night. Her arms were folded tightly as if she was cold. "It's a Deathwyrm."
Peppermint Butler gasped.
"That sounds awesome and messed up," Finn said.
Bubblegum frowned. "I've never heard of a Deathwyrm before."
"They haven't been around in a long time." Marceline's voice was flat and somehow she seemed older than usual. "I only saw them once before, back when I was a kid, right after the Mushroom War. So many people died all at once all over the world. Death couldn't collect the dead fast enough, so he made Deathwyrms to help."
"That doesn't sound too bad," Jake said. "Nobody wants dead bodies lying around, festering up the place."
Marceline finally turned to look back at them. "It doesn't just eat dead bodies. It takes the lives of anything in its path, whether they're done with them or not. That's why Death recalled them when they were done."
"Whaaaaat?" Finn gasped.
"So this creature's loose in Ooo, stealing lives from our people?" Bubblegum demanded, aghast.
"Don't worry, Princess," Finn said. "We'll go kick that worm's butt and get these souls back, like we did with Marcie's dad."
"This is worse than that, Finn," Marceline growled. "My dad just steals souls. The body's still alive for the souls to go back to. If this thing gets you, you go to the Underworld and you're dead forever!"
"So whatever released this thing intends to annihilate every living thing on the planet!" exclaimed Bubblegum. "It'll be the Mushroom War all over again!"
"Oh, glob! Why aren't we out there killing it already?!" Finn shouted.
"Uh, how exactly do you kill a giant death snake?" Jake asked.
Marceline shrugged. "I don't know. No one's ever killed one before."
Finn's eyes widened and shone. He turned to Jake, almost shaking with excitement. "Jake, do you know what this means?"
"I know, dude!"
"We're gonna be the first people to kill a Deathwyrm!" they yelled in unison, leaping up to high-five. As everyone else stared at them, they remembered the tone of the room.
"Uh, sorry." Finn blushed. "But we've got to get out there and vanquish this insanely rad monster. PB," he said, turning more serious, "I know you probably want to take care of your people, but we could really use your science mojo to figure out how to stop it."
Bubblegum sighed. "There's nothing I could do from here anyway. I just wish I could know they would be safe while we're away."
"You've got a PA system, right?" Marceline asked.
"For royal announcements and karaoke showdowns, yes."
"Deathwyrms are blind, but they're super sensitive to vibrations. They hate high-pitched sounds. I can set your system to blast feedback over the kingdom while you're gone."
"Perfect." Finn glared out at the night. "Let's do this."
OOO
The center of the kingdom was filled with Candy People. The Banana Guards and castle staff bustled through the crowd, passing out marshmallow ear plugs.
Up on the dais, Finn walked over to Flame Princess. The girl was leaning on the wall, her arms caramelizing the peanut brittle bricks.
"You okay, FP?"
"I'm just worrying if the Deathwyrm is attacking the Fire Kingdom. I haven't seen my father since I moved out." She looked up at Finn. "What if that was the last time I talk with him, and we were fighting?"
He wanted to reach out and touch her hair or shoulder, but his gauntlet was already packed. "It'll be okay. We're gonna beat it and you'll get to make up with your dad someday."
She scowled and her fire flared a bit. "Oh, I don't want to make up with him. But I want to know he's still alive to be mad at."
Finn laughed nervously.
Princess Bubblegum walked out onto the dais with a bullhorn. "Everyone ready?" she called to the crowd. "We're about to begin."
Finn put his earplugs in. Flame Princess covered her ears with her hands. The Candy People below got ready.
Marceline gave Beemo a thumbs-up and he put his speakers near the microphones of the PA. The shrill whine of feedback pierced the air.
Finn noticed Peppermint Butler standing nearby and walked over. He leaned down and gestured the butler to unplug one of his ears. "I need to ask you a favor!"
"Yes, Master Finn?" Peppermint Butler shouted back.
"Could you use your connections with Death to find out why one of his pets is running loose?"
Peppermint Butler winced at the shrill noise around them. "Gladly, sir."
Bubblegum gave Marceline a thumbs-up in return and turned back to the crowd. "My people, I will return soon—"
The crowd milled about obliviously.
"I said, my people, I will—Ah, forget it." Bubblegum tossed the bullhorn aside and walked over to the others gathered at the Morrow. "Let's go!"
"What?" shouted Finn.
Bubblegum rolled her eyes and dragged him aboard. As they all climbed on, Jake looked back from the dais. "Hey! At least let a guy know when we're leaving!"
"What?" Bubblegum called back.
OOO
"So how are we gonna find this thing?" Jake asked as they flew through the night.
"Hm." Finn thought. "It's going to home in on the nearest group of living things to where we last saw it, so maybe the goblin village?"
"Aw, man," Jake groaned. "Didn't they just finish rebuilding after Flame Princess's attac—I mean, masterpiece?" He gave her an awkward grin.
"What I don't get is why Death would make a monster to collect the dead that also killed living people," Bubblegum said.
"He figured the Mushroom War had wiped out everything," Marceline explained. "Most of the people who survived the main War were so messed up that death was a mercy. But he didn't expect all the new lifeforms that came from the War. When he found out, he called off the Wyrms."
"But why would he set one loose now?" Bubblegum wondered.
"Hey, look, trail of death." Jake pointed to a path of dead trees and grass through the forest.
"Oh no!" Finn gasped. "That's LSP's camp!"
They swooped down and landed the Morrow among the wreckage of Lumpy Space Princess' belongings. Her food was scattered everywhere, her garbage possessions shredded and strewn across the clearing. Near the center of the clearing were several piles of bones.
"Oh, glob…" Finn breathed. "LSP?"
"Finn?"
They all looked up at the voice and saw Lumpy Space Princess clinging to a branch high in one of the nearby trees.
"Oh my glob!" she yelled, half-floating, half-falling out of the tree, sap and leaves stuck all over her. "Thank glob you guys are here!"
"LSP, are you okay?" Finn asked.
"It was horrible, you guys! This giant snake thing attacked my home! It was so nasty!"
"I know. We saw it trashed your camp."
"Um, nah, it was already like that. I had a party last night," Lumpy Space Princess said.
"Oh."
"What about the piles of bones?" Jake asked.
"They're from the hot wings from the party. Except for that one," she pointed to one of the piles. "That was Mickey. I told him the party was over at eleven last night, but he wouldn't lumping take a hint and leave. I'm glad the snake got him."
They all stared at her with slightly more horror than usual.
"Uh, did you see where the snake went?" Finn asked.
"Yeah. It went that way, toward that grody goblin city."
"Thanks!" Finn called as they climbed back onto the Morrow.
"See if the snake will come back after my next party to clear everyone out!" Lumpy Space Princess shouted after them.
OOO
As they approached the goblin village, they could already see the Deathwyrm slithering between the buildings. The goblins were clustered on the upper levels of their tallest towers, screaming.
Finn rose up on the back of the Morrow, drawing his sword. "All right, man, you ready to burn our names into the history books?"
"You know it, dude! I'd go gaga to star in a saga!"
They leapt off the giant bird and tucked and rolled as they landed on the street near the monster.
"Hey, Deathwyrm!" Finn shouted. "Time to leave Ooo alone and go home! We're not dead yet!"
The serpent's head turned toward him, fangs extending.
"Aw, man. Why'd you have to say 'yet'?" Jake moaned.
"Just stay away from its mouth," Finn said.
"Believe me, none of my plans involve going near its mouth." Jake stretched up above the wyrm and made his face look like a skull. "Hey, look at me! I'm a rotting, half-dead body that just wants to die already! Brains…"
The serpent didn't even turn, still pursuing Finn, who dodged a strike of its tongue.
"It can't see." Marceline hovered beside Jake. "It hears your heartbeats. Try this." She strummed some low notes on her bass guitar.
The Deathwyrm's attention flickered to her just long enough for Finn to run around its side, away from its head.
"Its weakest point should be the very top of its head or the middle of its belly between where its ribs end," Bubblegum called from her aerial vantage point.
Finn rolled under a coil of the Deathwyrm and jabbed his sword into its stomach. The blade sunk in about a foot and the creature howled in pain.
"Yeah!" Finn whooped. "My sword hurt it a little!"
In his moment of celebration, the wyrm's tail whipped around and smacked him, sending him flying backward against a wall. His sword landed a few feet away, out of his reach.
"Finn!" Jake yelled, punching the wyrm with a gigantic fist. The monster didn't even pause. Marceline hacked it with her axe, but the blade didn't make much more impact than Finn's had.
Finn gulped as the serpent's head reared back to strike.
"No!" Flame Princess screamed, an inferno pouring off her hands against the Deathwyrm. It let out a shriek, its side blistering and blackening. It dove into the earth, boring a tunnel to get away from the raging fire elemental.
The goblins watching from the towers cheered the victory until the wind carried a few embers their way and set a building ablaze again.
Jake sighed. "I'll go save the goblins."
Flame Princess shrank back down, dimming her fire, and ran to Finn. "Finn! Are you all right?"
"Yeah," Finn was gazing at her in awe. "That was amazing! That was, like, six—no, seven kinds of awesome! You are so coming adventuring with us from now on!"
Flame Princess glowed at his praise.
"So now we know fire can harm it," Bubblegum said as the Morrow landed. She scribbled on pieces of paper. "Based on its previous attacks, I believe I can extrapolate where it may surface next."
"Or we can just follow the giant hole it dug in the ground," Marceline pointed out.
"Not all of us can see in the dark as well as you can."
Marceline gestured to Flame Princess. "She's a living torch."
"Yeah!" Finn said. "And if we catch it in the tunnel, we can attack it from behind and it can't turn around to hit us back!"
Bubblegum sighed. "I suppose you have a point."
Jake walked back over, smudged with soot. "The goblins have a pretty good bucket brigade going. What's the game plan?"
"Go down the wyrmhole and toast its butt till it croaks," Finn answered.
"Oh," Jake said. "Neat."