After the war-that-wasn't, after Betty almost destroys the world and then saves it for the sake of one person, after she says goodbye to Finn and Jake and everyone who helped fight back Golb, and after kissing Bonnie for five minutes straight, Marceline finally peels herself away from a very pink, very inviting pair of lips and the princess attached to them.

Bonnie looks disappointed for a second, but nods. "We'll finish this later?" she asks, more gently than she's spoken to Marceline in...well, a really long time.

Marceline doesn't really know how to feel right now. A lot of emotions are swishing and swooshing and slopping around in her, mixing in a thousand weird ways. Still, she knows she very much wants to finish this up.

"Yeah," Marceline says. "But you have to get back to your candy citizens, and well..." Marceline looks back to where she'd briefly handed Simon off to the weird Ice King guy that used to be Gunther. (Golb-or Betty? Who knew anymore?-that crown was so annoying. Since it helped save the universe, though, she's willing to cut it some slack.) She sighs. "Simon needs me right now. He helped me so much, and I could never help him, all of these years."

Bonnie nods. "I can't believe Betty actually saved him. Her ingenuity was truly incredible, her devotion even more so."

Marceline can't help a snicker. Bonnie was, well, it was great to finally to be back on the "will they" of the whole "will they or won't they" thing, but she still was such. A. Nerd.

Waving her goodbyes, Marceline watches her new/old girlfriend troop off to rally her people and begin rebuilding.

And isn't she a pretty picture as she leaves.

"I just can't believe...she's really, well, gone and turned herself into Golb," Simon weeps. "We finally had the chance to be together! Finally, she'd worked so hard, and everything! And then she went and sacrificed herself? How could she do something like that?"

She'd flown them to her cabin, and Simon sits on her couch. It's impossible to believe he's here, honestly. She's seen one or two snatches of him in the past centuries, and she's never hoped for more. Not after the fifth time the Ice King crashed one of her parties and tried to pick up every princess there, nope-she'd never hoped for more.

And now, Simon is...back. Back, and miserable. And as the only person in Ooo who knew him before he got Ice King-ified, she has the best chance of helping him. Well, she wants to help him, but she doesn't know if she can. Yeesh, she was always bad at giving romantic advice.

"Yeah," Marceline replies. "It's...pretty awful."

"Yes!" Simon shouts. "How could she do it? To either of us? Why would she? Doesn't she want to finally be together?"

"I mean, you couldn't really be together if the universe was all Globbed up."

"Well, yes...but still! Doesn't she want to be together?" He's sobbing again, and she moves closer on the couch and gives him a hug. Honestly, she should've known better than to try to use logic with this kind of situation. Instead, she gestures at the cup steaming in front of him. "Try some hot chocolate."

Simon breathes out in a sharp huff, but brings it to his lips. He takes a quick sip, and frowns, then looks down and inspects the stuff. "This tastes...interesting."

"Well, I mean, you did sort of...miss a thousand years, here and there." Marceline shrugs. "A lot of things have changed. Including cocoa beans."

"Fascinating," he murmurs. He sips again, then drinks more deeply.

Marceline drinks a bit from her own glass, draining the red from it. When she looks up, Simon's staring at her with wide eyes. "Don't worry, it's not blood or anything. It's fruit punch. And I just drink the red color."

Simon takes off his glasses and rubs the tears from his eyes. When he looks up again, well-well-he looks so normal, so human, it's almost unreal. "I know. I mean, I didn't know, but-well, I know you would never change. Not like that."

Simon's smile is slow and so, so warm. It makes her think of how he used to remind her of her mother. Something about the shape of his face, the slant of his smile.

Marceline flicks her tongue at him. "Well, you don't know that. I am the Vampire Queen, after all."

She takes Simon back to his cave, to grab any of his old stuff he might want to take. He can't live there anymore, not in the freezing cold. Humans weren't meant to spend so long in temperatures like that, she'd almost forgotten.

(Finn, well, he might be human, but he's a child of Ooo, and he understands how to survive it in a way Simon simply doesn't.

Yet.)

As Marceline hovers by the throne, watching penguins accompany Gunther/Ice King in a musical number, Simon stumbles around in a daze. "I really built all of this?" he asks her, over and over, looking at the furniture, the cages, the tunnels upon tunnels. She gives a noncommittal mmmm in response to pretty much everything he says. Like, he did, kind of? After all, Ice King was only sorta him.

Eventually, he finds his way down to the chamber where Ice King built some massive statues of those female versions of Finn and Jake he'd dreamed up. Yeesh. When she sees the look on Simon's face-

"Well, it's impressive work," she offers weakly. "Good detail."

Simon looks like he's going to explode. Like he's going to be sick. "But how could I be doing this? All of this, all of this for so many years?" He grasps his hair, fists bunching around short, dark, thick locks, so unlike the Ice King's brittle white hair. "What was I thinking! How could-how could this be me!"

Simon is freaking out, and honestly, it makes the part of Marceline that remembers being seven years old and needing Simon for absolutely everything rush out. She doesn't want to do this. She wants Simon to be happy he's back, happy he's here, that he can be with her, that he can do all of the cool archaeology things he'd always told her about, except even better, because it would be in Ooo.

But right now, Simon is lost in the infinity between one-thousand-and-forty-five and forty-five, and, well...part of Marceline might still be seven, but the vast majority of her feels every one of her one-thousand-and-five years, thick and heavy as the trunk of her old treehouse.

She reaches out, and grabs him, her blue hand strange against his darker one. Back then, his skin had been blue, and hers had been gray. But it wasn't that way now.

"Simon."

"Yes, Marcie?"

"That was...it wasn't you. It was the crown. You have to understand that."

He looks so, so miserable. "I know, Marcie."

Simon living in the swamp with her should be great. It's everything she's ever dreamed of, after all.

But it's not.

He's so confused, having such a hard time grasping the massive time jump that feels, according to him, more like "some really abstract dream" than anything else. He's sad and tired, and he keeps talking about Betty. Marceline tries to talk back with him, tries to understand what he's going through, but after a while, it starts to grate on her. Betty sacrificed herself for him, yeah, but she did it so he could live a good life! And now he's just drowning in sadness and going nuts over Betty, the same way Betty was about Simon.

Every time Marceline goes to visit Bonnie-now definitely her girlfriend again, yay-or Finn and Jake and BMO, or any of her other friends that are so very gradually rebuilding their lives, she asks Simon if he wants to come. He refuses.

After two weeks of this, as she'd expected, Finn kicks down the door.

Well, sort of expected. "Where's Jake?" she asks, as Finn basically hoists a loudly-protesting Simon over his shoulder.

"He had a date with Lady Rainicorn he just couldn't miss." Finn gives her one of his little half-smiles. "Guess it's gonna be a human-only adventure, then? Unless you wanna come?"

"Nah," she says. "You boys have fun."

Simon shoots her a furious look. "Marceline, I thought you said I could stay with you as long as I wanted."

"I'm over a thousand years old. I have a complicated moral code."

Even so, when Simon isn't back a week later, she can't help but start getting worried.

Two weeks later, Bonnie and Jake are officially tired of hearing Marceline freak out to them.

They're in Bonnie's lab, watching the resident scientist try to figure out how to strengthen Neddy's candy juice enough to heal the Guardians. It's probably a lost cause, but in Ooo, you never know.

"I told you, Marceline, they're fine! Finn is an expert, and from everything you've told me about Simon-well, he was tough enough to survive the aftermath of the Mushroom War, wasn't he?" Bonnie asks. She fiddles with one of her vials and makes a note on the pad of paper next to her workstation.

Marceline knows Bonnie is right. Finn's awesome enough to work any kind of escort mission he wants, and Simon might not be used to Ooo, but it would be idiotic to underestimate him because of that. And he is a genius and junk, too.

Still.

Still.

Jake slumps over in his seat. "Hey, I miss my bro too, you know. We even called off finding a new place to live so he could go and help Simon out. I like living with Lady Rainicorn, I mean, but-" he shrugs. "You gotta have patience. They're a-okay. They got through Glob, didn't they?"

Marceline knows Jake is right. She still wants to snap at him or turn all demony and go berserk or something. But she's a grown-up now, so she manages to resist.

Simon and Finn come back two days later, bruised, muddy, and sporting identical grins and a bundle of ancient human artifacts each.

The second Marceline sees them, all of her worries fall away like shedding a too-small shell. When Marceline flies up to greet them, Simon gives her a massive hug and bursts out a story about a six-village conflict that he and Finn helped settle-"Not bad for his first time," Finn whispers in her ear-then shows her his treasures. Old signs, musical instruments, a few twisted pieces of rusted metal furniture, and even a couple of dusty, cracked Christmas ornaments.

"I must admit, Marcie," he says sheepishly, "It's an interesting position to be in, to archealogize relics from an ancient civilization that I was part of."

"You're catching on," she replies.

"Yeah," Finn says. "All of this is old human stuff, right? Hey Simon, tell me about some of this junk." Finn can't hide it, though-he might seem as mellow as ever, but his eyes are practically sparkling with delight.

It's been so long since anyone talked about this kind of thing. Simon launches into stories from a world that he lived in much longer than Marceline ever did, and Marceline bobs in place, lounging comfortably on the air, and enjoys being in the same room as multiple people who know what Santa Claus is.

Simon comes to a few jam sessions with her and her friends. It's sort of embarrassing, kind of like if she'd invited her dad along-well, if her dad wasn't a total jerk-but it's still nice. Simon got pretty good at the drums, at some point over the last thousand years.

One night, she and Bonnie are cuddling on the couch. watching Ice King perform a puppet play. In the kitchen, Simon and Turtle Princess pop popcorn. It's cozy. Very domestic.

She catches Bonnie staring at Simon and leans over. "Hey, girl. Eyes on the show, don't be rude."

"I know," Bonnie mutters. She wrenches her gaze away. "It's just-it's strange to see him like this."

"Talking to a princess without proposing to her?"

"No. Without the mood swings, I mean. He's just...so happy."

Later that night, when most everyone is sound asleep, Simon finds her outside, playing herself a little lullaby.

"What's up?" she asks, pausing in her strumming.

He pulls a drumstick from his pajama pants and taps it idly against his leg. "It's very strange, you know, to suddenly be able to be able to play a musical instrument out of nowhere." He breathes deeply, and says in a rush, "But it wasn't really out of nowhere, was it?"

Marceline thrums her bass without thinking. It's a nervous habit. The chords echo around them.

"That was me," he says. "In a way. And I need to accept that."

Marceline heaves a sigh. "This stuff is heavy, man."

"Marcie." His tone is stricter than she's heard from him in centuries, and when she looks up, he's-so focused. So intent. "I need to go and find Betty. And if I want to do that, I need to accept what happened to me. What she saved me from. There were good times, I suppose. I made some friends. I had fun. The penguins were cute. But I was so, so lonely, and so confused, and I couldn't understand why."

Marceline closes her eyes and tries to focus on her strumming.

"I'm so proud of you."

Her fingers freeze on the strings.

"I've heard from Finn, what it was like. What I was like. It must have been painful." His eyes shade down. "I remembered some of it. A bit." A pause. "I tried to kiss you, Marcie."

Marceline wants to shrug it off, wants to say it's okay, wants to be strong. But she looks at him, so young and so old, and the truth comes out. "It was so hard."

Without thinking, they embrace, as easily as they used to. "I know," he says and brushes her cheek with his hand. "I know."

"I missed you. You were there-but no matter what I said, I couldn't get the you that I wanted!"

They fall over each other, onto the rough planks of the porch. She curls up into his chest and hears him spit some of her hair out of his mouth. "I can imagine."

"I know you were just trying to protect me, but the crown-that damn crown!" She punches the floor in emphasis, accidentally breaking a few boards. Whoops.

She cries, and he cries, and it feels awful, but to have someone to hold her when she cries again-well, she has Bonnie now, again, but she missed Simon. It's nice.

It's really nice.

They stay like that for a very long time.

(It's not a thousand years, but it honestly feels like it.)

The next morning, over breakfast, Marceline forces herself to ask a question which she very much doesn't want an answer to.

"So, you said you're going after Betty?"

His gaze is sorrowful as he slurps his cereal. "She's my princess, Marcie. I miss her. So, so much. And she worked so hard to get me back-she might be even further gone than I was, but I have to try. At the very least."

Marceline understands. It burns her, that Simon won't just stay here and be happy with her and with new friends, but he and Betty, it seems, are definitely meant for each other. In that case... "Do you want my help?"

Simon appears to be almost surprised at the offer, but it seems to do him some good. He goes back to his cereal just a little bit more cheerful. "That's very generous, but I wouldn't want to take you away from your friends. They need your help, too, and God knows you've spent enough time looking after me." He looks back up, hesitant. "If I'm still searching in-I don't know, how long did it take Betty to free me?"

Marceline feels that warm feeling bubble up again, and against her will, she finds herself smiling into her morning cup of dyed-red coffee. (No, it doesn't give her a caffeine boost. It's the principle of the matter.) "A couple of years, I guess?"

Simon holds up his cup of normal coffee. "A couple of years, then?"

They toast. "It's a promise," says Marceline.

"Cheers," Simon says, then leaps for her bass. Playing a few slightly funky chords, he bursts out, "Making your way in the world today, takes everything you got..."

Marceline laughs more that morning than she has in a very long time.

Life happens.

Death happens.

One day, Marceline leaves her shack. When she comes back, it's been a very long time, and two weirdoes have taken up residence.

AN: Adios, Adventure Time. Here's to ten seasons plus an infinity of adventures.

Constructive criticism is always welcomed.