Blinding light from the outside world bled into the pitch-black cave below it. The ceiling of the massive underground tunnel was spiked with stalactites and the river stood still. Fionna and Marshall Lee hung in the shadows as they prepared for their activity of the day. Fionna stood on the dock, her deep blue shirt just a bit more low-cut than normal. She was practicing her beatboxing for the project, her voice bouncing off the cave walls into the darkness. Marshall sat nearby, his thin legs dangling off the dock as he tuned his electric bass.

"Thanks for helping me record, Fionna," Marshall said, breaking the near silence as he hit a few notes on his bass.

"No problem, Marshall!" Fionna chimed.

Marshall grew nervous about what he was about to do, but he had to let his feelings out somehow. The entire reason why he had invited Fionna over was for this one song, and the opportunity to finally get this heavy feeling off of his chest. But he began to have some last-minute doubts, thinking that he might have just made his dilemmas worse. Then again, Fionna was his friend, and he could always trust a friend. He had to do this inside the house, however.

"Now, I'm going to sing something really personal," Marshall warned. "So don't laugh at me."

"I would never dream of it…ma' man," Fionna giggled.

Once inside Marshall's home, they set up the equipment and prepped for the song.

"Now, start a slow beat and keep it steady," Marshall instructed. "Or it'll mess up everything."

"You got it!" Fionna chimed. She began to beatbox, pulling a large pair of headphones out of her pack and over her ears. She then picked up the recording equipment which consisted of a small tape recorder and a microphone and continued to beatbox as she brought the objects closer to her.

Marshall struck some notes on his bass and started to sing.

Mom, you ate my onion rings

They were mine, yeah, that's the thing.

But you ate them, yeah, my onion rings

I was mad, didn't have a side to my wings.

Mother, you are such a bother

And I wish you would stop

I'm about to drop

What kinda mom eats her son's onion rings

The ones that ruin everything

Mother, there was rage there

If you saw it, would you even care?

Fionna's beatboxing slowed to nothing as the song ended. Her heart felt heavy and ached having heard the song. She had no idea Marshall was so hostile to his mom, or that it was secretly ripping him apart. She sighed with sorrow and sympathy.

Marshall noticed that Fionna had stopped beatboxing and became irritated. "Fionna, you messed the beat up!"

"Marshall, if you've been thinking about your mom so much, why don't you go see her?" Fionna asked, heavyhearted.

Marshall sighed. Fionna just wouldn't understand. "She's not worth the effort," he grumbled.

"Not worth what effort?" Fionna asked curiously.

Marshall became inwardly angry. He really didn't want to see his mom after that incident, but he couldn't tell Fionna that. She wouldn't care. He had to convince her that approaching his mother was too physically demanding. "Well," he started, "first I'd have to draw a circle with a mean face in the center, and then…uh…douse it with orange juice."

"Oh yeah?" Fionna had been drawing exactly what Marshall Lee described, and quickly ran for a carton of orange juice. She found some and flung it at her drawing on the wall.

"And then," Marshall continued, "you're supposed to chant something, like: Veloso vobus et kom spiritum!"

Fionna chuckled, joyous to notice that her drawing on the wall was glowing, and the spell was working.

"But I really don't want to see her," Marshall grumbled. "I'm still mad about the onion rings."

The once gentle yellow glow in the wall intensified, turning fiery red and shaking the entire house. Fionna and Marshall were thrown backward and stared in shock as the walls opened up and a figure appeared inside it. It formed into a lean woman with long dark hair and what looked like black lawyer's clothing. She had the same sharp teeth and pointed ears as Marshall, but her eyes were scary and cat-like, and her cheeks were deeply sunken.

"Marshall Lee!" she exclaimed, catching sight of her son.

A fit of rage burst deep inside of Marshall when he realized what had happened. Gritting his teeth furiously, he turned to his friend. "Fionna, what did you do!"

"I…reunited you with your family?" Fionna answered, frightened by all that was going on. She began to think she had done something terribly wrong.

Marshall hissed at her. He couldn't believe what Fionna had done.

The woman glanced at Fionna, then turned her attention to Marshall. "Is this chick your evil slave?"

"I am not evil, Marshall's mom!" Fionna exclaimed defiantly. "I'm a good guy! Well, not a guy, but…"

"Good?" Marshall's mother echoed. She bared her pointed rows of teeth at Fionna and roared, frightening her futher. She grabbed Fionna and opened her mouth wide, sucking the life out of the helpless girl.

"Hey!" Fionna barked. "What are you doing, you creep!"

"Stealing your soul," the woman answered.

"Mom!" Marshall screamed, forcing himself between his mother and Fionna. "You always do stuff like this!"

"Oh, Marshall," she said, rolling her eyes. She caught sight of his bass and snatched it from her son's hands. "What is this? Some kind of instrument?"

"Give it back and get out of my house!" Marshall ordered.

"Talk like that will only get you grounded, young man!" the woman warned. "I have business to attend to: sucking up all the souls in Aaa."

Fionna was mortified by what she heard. "What? No!"

"See you kids later," the woman said, opening the door. "Have fun." And with that, she morphed into a massive beast and left the house.

"She took my bass!" Marshall growled.

"I've unleashed evil onto Aaa!" Fionna shrieked, mortified by what she had caused. "Marshall, we have to stop her!" She ran out the door to follow the woman.

"Fine," Marshall grumbled. "But I'm just going to get my bass back."

Marshall held Fionna by the arms and hoisted her up, then they flew together through the skies in search of the creature they had released.

"So how do we kill this thing?" Fionna asked.

"You can't kill my mom!" Marshall barked.

"Oh," Fionna said, extremely regretful that she had suggested such a thing. "I'm sorry, I didn't mean…"

"No," Marshall interrupted. "I mean you literally can't kill her. She's immortal."

"Oh," Fionna mumbled. Suddenly, she spotted a potential clue. "Look! A gathering of fluffy people! Maybe they saw your mom!"

Marshall quickly agreed and lowered them to the ground, where the fluffy creatures were trembling with fear.

"They're all flipping out," Fionna noted.

"They're probably scared of him," Marshall suggested, pointing to a floating fluffy person with white, dead eyes. He picked it up and examined it, then frowned and tossed it back downward. "Yeah, my mom's been here. Let's go."

"No!" Fionna objected, approaching the zombified creature. "We can't just leave him here. We gotta help this guy." She opened her pack and withdrew some containers filled with food. "I've got some soul food that Cake packed for me."

"Look, you wanna help him?" Marshall said. "Help me get my bass back from my mom!"

"How will that help…"

Marshall's eyes went black and his hair stood up on end. He bared his teeth and roared: "MY MOM STOLE MY BASS GUITAR! And when I get it back, I'll break it over her stupid head and throw her back into the nightosphere!"

"Fine," Fionna mumbled reluctantly. "But first we have to return all the souls your mom stole. Right, Marshall?"

Marshall scoffed. "Whatever."

After some journeying, they came to a massive blue canyon littered with skulls and covered in boulders.

"This is Blue Rock Pass," Marshall explained. "If my mom wants to get through the mountains, she'll have to go through here."

"Perfect!" Fionna exclaimed. "We can smash her with a rock, then once she's under it, all the souls will return to their rightful owners."

Just then, they heard the woman lurking deep in the canyon. Fionna tried to move a nearby rock to crush her with, but before she could, Marshall dove head-first into the canyon, hissing and spitting as he closed in on his mother. But the woman ducked out of the way and Marshall nearly collided with the rock wall.

"So this is how it's gonna be, huh?" the woman growled.

Marshall continued to hiss and lunge at his mom, determined to steal back his base. He fought hard against her, but she was too strong for him.

"Marshall!" Fionna screamed. "Keep her right there!" And with that, Fionna shoved the boulder down the cliff with every ounce of strength in her body. The massive rock tumbled down the cliff face, but Marshall's mother managed to dodge it.

"You know you can't destroy me!" the woman said defiantly.

Realization dawned on Marshall and he calmed down. "No, Mom…I don't want to destroy you. Just…JUST LEAVE ME ALONE!" He flew out of the canyon and sat beside a discouraged Fionna.

"What happened?" Fionna demanded. "I thought we were a team. We're supposed to stop your mom from stealing everyone's souls!"

Marshall sighed. As much as he hated to admit it, the truth had to come out. With a deep and brave breath he mumbled: "I just want my mom to know I exist."

Fionna said nothing. She just stared expressionlessly at her broken friend. She knew in that instant that she had to do something, anything, to settle things between Marshall and his mom.

Marshall's mom's rampage took her to the Ice Kingdom, where she began sucking the life from the local penguins. But one of them managed to escape and rushed to alert the Ice Queen.

"What is it, Gretchen?" the Ice Queen asked, disgruntled from being interrupted.

The penguin pointed in the direction of the woman as she sucked a soul from one of the penguins. Upon realizing what was happening, the Queen grew furious. "Nobody sucks the life from my penguins except me!"

She rushed to confront the beast, screaming: "How dare you trespass upon my domain! You shall pay for this!"

The Ice Queen raised her hands and summoned her powers of icy white lightning, but the woman turned to her and distorted into a horrid beast. The Ice Queen became frightened.

"You know what? I think I left something in the oven," she shuddered before fleeing toward her castle.

Marshall's mother sucked out the remaining souls from the penguins and grew to gargantuan size, loving the sheer amount of power she suddenly felt pulsing through her. She knew that her mission was almost complete.

Fionna and Marshall spotted the towering woman as she rampaged through the field and continued to absorb the souls of all she came across.

"Whoa, she's huge!" Fionna noted. She was terrified by the sight, but also knew she had to defeat the beast she had unleashed. "I'm gonna take her down!"

"Fionna, you're way too small to take her down," Marshall said.

"No way!" Fionna barked. She yanked a nearby sword out of the ground and held it up, ready for battle. "I have to release those souls!"

She charged the monstrous woman, sword in hand, yelling: "Hey, lady! Give up those souls!"

The woman stared down nonchalantly at the duo, then turned to her son. "Oh, Marshall. Are you still following me?"

"I'll stop following you once you cough up my bass!" Marshall yelled.

Faster than either Fionna or Marshall could register, the woman morphed into an unstoppable monster with a large head and long, black tentacles. A pouch underneath her neck revealed the many souls she had captured. Fionna began to climb her leg in an attempt to reach the souls, but she was quickly snatched up by one of the woman's long tentacles. Squealing with fear and disgust, she thrust her sword into the tentacle and chopped it in half. She plummeted to the ground and Marshall's bass fell with her. Marshall caught it just in the nick of time.

"Give that back, young man!" Marshall's mom demanded. "You are so disrespectful!"

"You don't respect anything!" Marshall fired back. "I'm leaving!"

"No!" Fionna objected.

"Fine!" the woman barked. "Go! I'll deal with you later."

"NO!" Fionna screamed. "Marshall, come back!"

"I said I'm leaving!" Marshall repeated.

Fionna's head was spinning. She had to create a diversion. Out of panic, she reached into her pack and withdrew the tape recorder from earlier. She pressed play and the slightly static-coated song she had recorded earlier began playing.

Both mother and son stopped in their tracks. Marshall stiffened, embarrassment overtaking his entire being, while his mom stood shocked by what she was hearing. Fionna continued to play the tape, unsure of what to do. Suddenly, Marshall's mother turned to him with soft eyes.

"Marshall, do you really feel this way?" she asked.

"Mom, no…" Marshall started.

"But Marshall, I do love you," she assured.

"Mom…"

"I'm sorry I ate your onion rings," she continued. "I didn't mean to make you upset."

"Mom, it's fine," Marshall grumbled.

"No it's not," she objected. "You have to understand that I love you, no matter what. Never doubt that."

Marshall sighed. "I love you too, Mom." He tried to make it sound nonchalant if not a little sarcastic, but what his mom told him secretly meant so much to him.

Without warning, Fionna attacked. She launched herself in the woman's direction and sliced open her throat, unleashing all of the spirits. She remembered the spell Marshall had told her to bring his mom out of the nightosphere and used that same spell to send her back. With a series of demonic screams, the woman disappeared into a fiery fog. Marshall was shocked by what Fionna had done.

"Fionna!" he barked. "Why did you do that!"

"What do you mean?" she defied.

"How could you humiliate me in front of my mom and then stomp her like that?"

Marshall swung his bass and aimed it for Fionna's head, but quickly regained his senses and lowered it, shuddering violently. "Well, I'm glad she's back in the nightosphere. That was emotionally exhausting."

"It was for me, too," Fionna agreed. "Only…for me, it was more physically exhausting." Without another word, she flopped backward into the grass.

Marshall carefully lay next to her. They were silent for several moments before Marshall spoke up. "Fionna, I've been meaning to ask you something." He pointed to Fionna's unusually low-cut shirt. "What's with that cleavage in your shirt?"

Fionna perked up and sat up. "Oh, Cake's in here!" she chimed. She opened up her shirt just enough to reveal Cake shrunken and snuggled in her chest. "Sup, Cake?"

Cake burped.