Marceline had kicked Ash to the curve and had never felt better. But there was one thing that bothered her as she sat in her room, why did she feel like something was missing? Or was it someone? She always told herself she never needed anyone, but now she felt as if she could use a warm hug or smile.
"What's happening to you, Marceline?" She wondered as she was lost in her thoughts as she gazed at her wall. "You're strong and independent. You don't need anyone. You never have. Why do you feel like you need someone?" As she began to think more and more on who it might be, if anyone, one name kept popping up.

"Marshall Lee?" she questioned out loud, leaving her more confused than ever.
Finn was out walking Jake when Fionna appeared with Cake. "Finn! She did it!" she yelled as she ran to the boy with her cat in her arms.
"Who did what?" he asked as he and Jake both stopped to look at her.
"Marceline," she said as she reached him, "she broke up with Ash."
"Really?" Finn asked. "So what about her and Marshall?"
Fionna's smile turned into a frown as she said, "Nothing yet, she's still in denial of her feelings for him. But my newest adventure is to get her on a date with him."
"Need any help?"
"Yes!"
"Ok then, let's go," Finn said as he let himself and Jake be dragged by Fionna.
"Yay!" she said as she went over to her house with Cake right by her side and Finn and Jake dragging behind her.

Marceline walked up to Marshall, "Hey," she said.
"Really?" he asked her slightly annoyed.
"What? I just wanted to see if maybe you wanted to come see me sing in the park or something" she asked him.
"After everything I've tried to do for you, all I get is a crapy 'hey' and an invitation to come see you play a few songs?" he asked as he turned to face her.
"Look Marshall, I just don't know about what's been going on with me, I've been trying to process everything, I thought that you wanted to be with me..."
"What? And you think my life is a walk through the fucking park? No, it hasn't been. You think I'm just a player because I'm a jerk? Nope, not that either. You think you know everything there is to know and you think that, that gives you a reason to judge me. Marceline Abadeer, I can promise you one thing, you're not the only one who's had a hard life," he said as he walked away, leaving her speechless.

As he thought back on everything that had happened in his life, he thought that maybe he wasn't good enough for Marceline anyway, she should just stay away from a guy like him. He picked up his guitar and started to strum a song. Soon enough he found himself singing.

"So long
Congratulations, break a leg tonight
What a shame
I heard the understudy died under the knife
Crying backwards under bedroom light

The operation

I don't think you'll ever love me
You'd better listen to your doctor…"

He picked up his bottle of beer and drank from it. Maybe Marceline was right to stay away from him at first.
The words of the song poured out of him and as he made it to one part of the song, he never felt such emotion.

"Please understand me when
I'd rather see you dead
Than live without me, so thirsty for more
Beyond the sea blue light I met the love of my life
She'd rather see me dead than face me
I like your starry eyes,
They yell surprise! Surprise!
I'm in love…but not for long

Our operation, call off the operation

Another wave has turned its back on me
Crashed back on the eyes of the first I see

(If your delicate eyes don't blink someday they might as well be gone)
Can count on anything. For you I'd count the salt under the sea."

His own feelings were confused he had convinced himself that he didn't want her, but then he'd think that he didn't want to see her with anyone else. He loved the way her eyes shown, he had no idea how long his love for her would last. But then he'd think about how he'd do anything for her. She's what he's always wanted, but was she worth giving up some parts of himself? Was it worth letting someone else see parts of himself he never left anyone else see? He had no idea.
He got up from the floor and walked over to get another beer, this would help him wash away everything.
Cheers to the girl who is either a light in the dark, or the darkness in a small spot of light in his life.

I know I didn't put the whole song, but I think that I got the parts that apply the most to what I was trying to convey. The song if you're wondering is "Currents Convulsive" by Pierce The Veil.

You're the answer I've needed, the question I've feared, I know light is your mother, but darkness I fear…