"I have to go away for a while, Bonnie."
Princess Bubblegum simply stared. "What?"
"I have to take care of some things in the Nightosphere and I won't be around." Marceline sighed and floated on her back for a while, eyeing the princess. She was obviously trying to hold back tears and it made Marceline feel bad; she didn't even want to leave. Her father, however, would create Hell on the Candy Kingdom if she didn't go. It was a sacrifice she had to make for the better of the people. Go figure.
"How long?" Princess Bubblegum asked after a long while, staring off at something that wasn't there.
"A few years. Maybe less, if I'm lucky."
The princess nodded. "When are you leaving?"
Marceline snaked her tongue out for a second and wiggled it. "Tonight."
"Oh."
They sat in silence for a while until Princess Bubblegum spoke up. "I'll miss you."
Marceline peeked at the princess and felt a tear run down the side of her face. She silently removed her favorite band shirt and handed it to her. "To remember me by." She explained. She got up and began to float out of the window. "See you later, Bonnibel."
Princess Bubblegum soundlessly put on the shirt and curled up into a ball on her bed. She let the tears go as she whispered,
"See you later."