Marceline dove down deeper into the Abyss, hoping to Glob that she wasn't too late.

Squinting, she searched the clouds for Bonnie, but even with her vampire eyes she could hardly see anything. The air down here seemed thicker than the air above, somehow. Like the clouds were heavy with something other than gas and moisture.

Too fast, the ground came into view, and Marceline pulled up mid-dive, mere inches from splattering herself all over the Abyss. She hung in the air and scanned the ground, grateful that the toxic fumes could not harm her but also intensely worried about Bonnie. She would have survived the fall—of course she would have survived, she was made of gum, after all—but these clouds were a different story entirely. If the princess was exposed to the fumes…

Marceline caught a flash of pink on the ground ahead of her and she rocketed toward it.

"Please be okay," she said out loud, landing hard beside an unconscious Princess Bubblegum. "Please be alive, please be alive."

Marceline knelt down and slid her arms underneath the princess, picking her up to carry her for the second time that day. She didn't check her pulse; she didn't check to see if she was breathing—there wasn't time. All of that could come later, when she was safe and out of these clouds.

"Don't you dare be dead, do you hear me?"

Wildly, Marceline shot forward, searching for somewhere—anywhere she could take the princess. She thought about trying to leave the Abyss altogether, but only Glob knew how much time Bonnie had left. They needed to get somewhere close, and fast.

There, just through that cloud. A cave yawned before them, and Marceline flew toward it.

She crashed through the entrance, barely registering her surroundings aside from a lack of any sort of immediate danger, and laid Bonnie gently down on the floor, cradling her head in her lap. "Please don't leave me, not like this" Marceline pleaded one last time before finally placing two fingers on Bonnie's pulse point.

Marceline's relief escaped in a gasp of air that was almost a sob. Bonnie was alive. Her breathing was shallow and her pulse was weak, but she was alive.

A fit of coughs jolted the princess from Marceline's arms, and she curled into a ball. "Marcy," she managed. "My pack."

"I'll find it," Marceline said, standing and flying from the cave. She hadn't seen any sort of pack when she had found Bonnie on the ground, so she figured it must have come off in the fall. It took a minute to locate—an agonizing amount of time when she knew the princess was alone and quite probably dying—but she found it eventually and raced back to Bonnie.

"Oxygen," the princess choked out, and Marceline rifled through the pack until she found a tiny, portable oxygen tank and a connected mask. She fastened the mask over Bonnie's mouth, thanking Glob that the princess was prepared for everything, and then finally let the tension in her shoulders relax. She laid down on the floor next to Bonnie, whose breathing had become much more even now, and curled up against her, placing a hand on the princess's chest just to reassure herself that she was definitely still alive.

Sighing, Marceline allowed herself to close her eyes, to calm her own frantic breathing and to slow her heartbeat.

She felt like she had aged a hundred years in those last ten minutes. But now the blind panic was wearing off, leaving her shaky and drained. What were they supposed to do now? The monster—monsters—had been winning. There was no way to get back up to where they had been fighting unless she flew Bonnie back through the toxic air, which clearly wasn't an option.

Marceline felt one of Bonnie's hands land on hers, and she opened her eyes to meet her gaze. The princess looked sad, but she squeezed Marceline's hand in reassurance—at least we're alive.

The princess sat up, forcing Marceline's sore, exhausted body to do the same. She pulled the oxygen mask off just long enough to ask "where are we?" before replacing it over her mouth.

With Bonnie safe and (hopefully) recovering, Marceline finally took a second to look around. To her surprise, they weren't actually in a cave at all, but some sort of building. What she had taken for an entrance through the haze of the clouds was actually a ragged hole in the side of the wall that looked like it had been blown through with some kind of explosive.

"I have no idea," Marceline said, standing up to take a better look. Scattered furniture was set up throughout the room—a couch, a couple chairs, a table. Even an old TV. Everything was in eerily pristine condition other than the coat of dust that settled over everything like a blanket. Photographs lined the walls, and Marceline floated over to examine them. A group of people—humans—ragged and dirty but smiling and posing outside what Marceline assumed was the exterior of the building she and Bonnie were in now. Another picture, the same group of people in a different room, now in lab coats and dust masks.

"Holy snap, look at this!" Marceline tore a third photo off the wall and handed it to Bonnie. A small town, surrounded by craggy rocks and cliffs. "Do you think this was the Abyss? Before it was, you know, the Abyss?"

Bonnie frowned, turning the picture over in her hands and removing it from the frame. She pulled the mask off again. "There's a date on the back." She showed Marceline, and the vampire's eyes widened.

"How could a photograph last almost a thousand years?"

Bonnie made a fist and knocked on the picture, producing a metallic sort of clang. "It's not a photograph," she said. "It's a laser etching on a metal slab." She coughed sharply, but waved off Marceline's worried attempts to help. "This was years after the Great Mushroom War. It looks like—maybe a settlement was founded in this valley, but—" She squinted at the picture, then broke into more coughs. Marceline gently took the picture from her and handed her the mask.

"You need to rest for a while," the vampire said. "Just stop talking, okay?"

Bonnie had enough energy to look annoyed, and Marceline bit back a smile. At least the princess was feeling better.

The vampire continued her search of the place. They seemed to be in a sort of community room. There was the lounge area she had seen before, but upon further exploration she also found a small kitchen area in the corner, and a dining room table. Marceline frowned, picking things up and putting them back down, opening doors at random. How was all of this stuff so well preserved if it was over a thousand years old?

Marceline opened another door. Her eyes adjusted well enough to see that it was a bedroom. In fact, as she kept going, she realized most of these doors led to bedrooms, except one that opened to a long, dark hallway that ended up only Gob knew where. "Hey Bons, there's a bed in here," she said, opening a final door. The farther the princess was from those fumes outside, the better. Bonnie followed her in, looking around with a wary expression.

The bed was covered in dust, which Marceline did her best to brush off before gesturing for Bonnie to sit.

Static crackled from somewhere within Bonnie's backpack—ccskch Princess cskcch can schsh hear me?—and Marceline fished out the walkie talkie that was producing the noise. "You really were prepared for anything," Marceline said, turning toward Bonnie. The princess only crossed her arms.

Marceline pushed the talk button. "Finn?"

"Marcy? Where's the princess?"

"She's okay," Marceline said back. "Kind of. We're alive. What's happening up there?"

More static buzzed, and Marcy flew toward the ceiling with the hope that the signal would be stronger.

"—swallowing candy people," Finn's voice snapped to life on the other end. "Jake managed to carry some of them out of the Abyss, but the monster is everywhere. We don't know how long we can hold it off."

Marceline pushed the talk button again, but Bonnie interrupted from below with a demand of her own. "Get my people to safety," she said, stifling a coughing fit. "We'll look for a way out of here and let you know when we've found one."

"Got it Princess." Finn's voice cut off as Bonnie's composure broke and she began coughing once again.

Marceline landed back on the floor next to the princess, who was pushing herself off the bed to stand. "No," the vampire said, putting both hands on Bonnie's shoulders and gently forcing her back down. "You have to rest."

"My people need me, Marcy—"

"Ten minutes," Marceline said. "Just give yourself ten minutes. You're not going to be much use to anyone in this state."

Marceline took a small amount of satisfaction in the look on Bonnie's face. After all, it had only been a matter of hours since the princess had basically said the same thing about her.

"Ten minutes," Bubblegum agreed at last, sagging against the old mattress. "But that's it."

Relieved, Marceline sat cross-legged on the floor and rested her arms on the bed beside Bonnie, then let her head fall into her arms. Maybe she could use ten minutes as well.

She felt Bonnie's hand slip into her own—slow, hesitant, like the princess wasn't quite sure how Marceline would react—and the vampire squeezed Bonnie's fingers back. She would have plenty of time to be angry and resentful once they were free from this place, but for now she just found comfort in that small burst of warmth that came with Bonnie's hand in hers.

"Thanks for saving me," Bonnie said after a while. "If you hadn't found me—"

"Anytime, Bon Bons," Marceline replied quickly, not wanting to even have to think about what would have happened if she hadn't found her.

Absently, the princess wove her fingers through Marceline's until they were interlocked. "I really owe you my life, huh?"

Marceline looked down at the ground, avoiding Bonnie's gaze. She really didn't want to think about it.

Something caught her eye—a cardboard box beneath the bed—and Marceline pulled her hand free so she could duck down closer. "Video Data Logs?" she read, raising a brow. She pulled the box forward, surprised to find it filled with tapes.

"Bonnie, check this out." She held up the box for the princess to see. "What do you think this means?"

Bonnie reached out to take one of the tapes from the box, and examined it. "Judging by the pictures on the wall and the labels on the tapes, I would say they're scientific logs of some kind." She handed the tape to Marceline. "Look."

"'Week Three:Breakthrough?" Marceline frowned, then sorted through the rest of the tapes, laying them in order on the floor in front of her. "These span the course of like six years," Marceline said. "It's a bummer we don't have a way to watch them."

"Don't underestimate the pack, Marcy," Bonnie said, pointing to her backpack.

Marceline rolled her eyes as she handed the pack to Bonnie, who produced a portable holo-projector from somewhere within. "I think you mean 'don't underestimate Princess Bubblegum's constant need to be prepared for literally anything," Marceline mumbled.

Bonnie handed the projector to Marceline, but her expression was pained. "I wasn't prepared today," she said softly. "And my people suffered for it." She looked down at her own hands. "Overconfidence is my biggest weakness. Just look at how I handled you and your memories." She clenched her hands into fists. "I should be better than that, shouldn't I?"

Marceline slotted the tape labeled 'week one: foundation' into the projector, then hopped in bed beside Bonnie and pointed the front of the small machine at the wall. She honestly wasn't sure how to answer. Luckily she was spared from doing so when the projector produced a bunch of static, then a picture appeared on the far wall: A human woman, exhausted and disheveled. She sat outside, on what looked to be a wooden crate, and she was rubbing her temples with her fingers as if she had a headache.

"We've finally found a place to settle down," she said, opening her eyes to look at the camera. "An old valley hidden in the middle of some of the sharpest rocks I've ever seen. We had a hell of a time getting down here, but I think it's worth it."

The camera cut to lush rolling hills and cliffs in the distance—the same landscape that had been featured in that picture from earlier. The land looked rich, fertile even, and Marceline leaned forward. Was this what the Abyss had looked like a thousand years ago?

"We're so tired," the woman on the screen continued, camera cutting back to her face. "The war has been over for almost a year, but it feels like some of us are still fighting it every day. These memories are exhausting."

The image melted back to static, and the two women looked at each other.

Wordlessly, Marceline removed the tape, then shoved the next one in: 'week two: exploration'. This one seemed to begin somewhere in the middle—the woman now wearing a lab coat and glasses, frowning deeply and pacing across what looked to be a small campsite.

"—found gas deposits around the entire valley. We may have to move again after all, find somewhere else to live—" more static "—more research to be done—"

The tape jumped forward in time, suddenly. The woman now looked excited, and she stood behind a man seated in a wooden chair. "We thought Elliot had left the valley during the initial analysis of the gas, but—" she placed her hands on the man's shoulders. "He was lost in the tunnel system the entire time. Tell the camera, Elliot."

The man's eyes darted back and forth, and there was an expression of panic on his face. "Look, I already told you, I don't know an Elliot. Who the hell is Elliot? Get me out of here!"

There was a crash, then more static.

Then the woman was back, pacing again in front of a now-empty chair. "This gas seems to work on the central nervous system," she was saying. "It pretty much wiped Elliot's memories clean from his brain. He can't remember anything." She stopped walking, faced the camera. "Bryan went out to the site and inhaled a bunch of the stuff—tried to make himself forget, too. He doesn't want to remember the war any more than the rest of us do. I know he lost his daughter, but he doesn't like to talk about it." The woman furrowed her brow. "It didn't work, though. I wonder if it's worth it to figure out why…"

The second tape cut off there, and didn't continue.

"So the Abyss was originally some kind of post-war refugee camp?" Bonnie mused. "But if the war didn't cause this buildup of gas, what did?"

"These scientists, obviously," Marceline answered. "It has to be."

"Let's watch the next one," Bonnie suggested, so Marceline put it in.

"—an old medical facility in the center of the valley. We're not sure why it's here or where it came from, but there are so many things we can use."

"That must be where we are now," Marceline supplied, recognizing the community room they had just left. It was an eerie feeling, to be sure.

"We're going to need to build a generator, but how…"

The tape cut forward again. "Breakthrough! I managed to isolate the compounds in the gas, and it's like nothing I've ever seen before; not even in theory. One thing's for sure, though—Bryan wasn't out there long enough for it to work on him. He would have had to spend hours breathing these fumes, like Elliot did." She slammed her fists on the table, making the camera jump. "If only I could get any of this equipment up and running again, I could—"

Another jump in time, the woman now decked out in full science gear in the community room. "—travelers from the north, many of them trained scientists. With their help I might be able to re-purpose this equipment. We could create a real, livable town!"

The image cut to the woman sitting outside once again. She looked run down; her hair coming loose from her low braid, her eyes troubled. She tapped her fingers on her chin. "We already knew how to isolate the chemicals in the gas, but…" Taking a deep breath, she looked back at the camera. "Some of the others want to build a machine." She paused, tapped her chin again. "A machine that utilizes the properties of the gas that erase memories. But instead of erasing, they want to replace the memories with new ones. Happy ones. They want to build a 'real safe haven' as they put it. A place where the war can no longer reach them."

Marceline raised her brows. Replace bad memories with fake ones? She glanced at Bonnie, who looked just as confused as Marceline felt.

"Bryan jumped right on board," the woman continued, "volunteered to be the first subject. I guess that makes sense. I think his memories haunt him more than the rest of us."

The tape ended, and Marceline reached for the next one. "There are some missing," she said, slotting another tape into the projector. "This next one is from like six months later."

"It seems word's gotten out about the machine," the woman said. "Those who survived the war—they're flocking here like birds. Buildings have popped up—our small valley is becoming a real town." She frowned deeply. "A whole town based on the desire to forget…"

More static.

Marceline picked up the last two tapes. "This is all that's left," she said. One of them was dated about four years later, and she shoved that one in.

The woman sat in the bedroom—the very same one in which Marceline and Bonnie now sat. Her eyes were puffy, hair limp. She was so thin her skin seemed to hang right off her bones.

"Are we doing the right thing?" she said softly. Her eyes darted back and forth, as if she were afraid someone might hear. "There are only a handful of us left who know the truth—the truth about what the machine even does—and that number is declining every day. Everyone else, well, they've forgotten." A flash of static before the picture resumed. "Farah and Clyde think we should let ourselves forget, too, and live out our lives like the others." Her eyes continued their quick movements. "But then who would work the machine? Who would be left to remember the world outside?" She raked her fingers through unkempt hair. "If I decide to forget, who will I become?"

The tape stopped, and Marceline hesitated before replacing it with the one she held in her hand. She turned to Bonnie. "This is the last one. A year later."

The image came to life: some sort of science lab. Everything was in disarray, knocked over or upside down. The woman paced back and forth, but her movements were frantic. Her eyes searched the room and her head whipped from side to side.

"This is it. They're trying to get in my head too, I can feel it." The words were hurried, spoken so quickly they were almost difficult to understand. "I've forgotten something, I know I have. The others look at me like I'm crazy but it's only because they've forgotten too."

The tape cut forward to the woman kneeling behind a metal box, crouched down and hiding from something. "It's the machine," she gasped out. "The machine is doing this."

Another cut to the woman sobbing and pulling at her hair. "Agh, I need to remember!"

A jump to the woman pacing once again. "I've already destroyed the other tapes. Nobody needs to know. Nobody needs to know about the machine because this can never happen again. This can never happen again I won't let it. I won't let it happen again."

Another cut. The woman screaming and hitting herself in the head with balled fists. "Remember!"

A blank screen, then the woman was straightening the camera. She had apparently regained some composure, but her eyes still held a thousand demons. "It needs to be destroyed," she said, strangely calm. "The whole thing needs to be destroyed. It's the only way to save us."

The tape ended, and the two woman sat in stunned silence for a moment.

"Destroying the machine must have released the gas into the valley," Bonnie said at last, voice sad. "All those people…"

"Became the monster," Marceline said. Her skin felt like it was made of ice, and goosebumps had sprouted along her arms. She turned to Bonnie. "Don't you get it? The gas and whatever Mushroom War goo was left over in the air—they must have combined to create that thing after the explosion."

Bonnie bit her lip. "You think the monster is some kind of fusion of everyone who used to live here? That they all died together and that—that creature was somehow preserved all this time by the Abyss?"

"It makes sense, doesn't it?" Marceline pressed, dread weighing heavily on her chest. "That would explain why it wants memories so badly."

"Dear Glob," Bonnie said, then her eyes widened. "Marcy," She lifted a hand to place it on the vampire's shoulder, eyes flashing with realization. "If I can fix that machine, maybe I can make a weapon. Maybe instead of killing the creature, we can simply make it forget!" Bonnie scrambled to get off the bed, wobbling a bit as she did so. "Let's go find that lab, it's got to be somewhere in this building."

"Woah woah, slow down Bons." Marceline grabbed Bonnie by the shoulders. "Are you sure you're okay to do this?"

"I'll be fine," the princess promised with a huff. "This is much more important."

Marceline narrowed her eyes, staring and Bonnie for a long moment before finally relenting. "Fine, but you're in no state to walk," she said, scooping Bonnie into her arms for the third time. "One of these doors leads to a hallway, but it's nearly pitch black."

"That's what you're here for," Bonnie quipped, tightening her arms around Marceline.

"Well, I'm glad I'm good for something," Marceline mumbled, taking off through the door, past the community room and then into the hall.

She shot one last look at the open door behind them before the two of them were swallowed by darkness.

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Getting closer to the end. I might actually cry. Thanks SO much to everyone who has been reading this/is reading it now. This whole thing has been so fun to write, and the comments have been so lovely to read!