"Psst. Hello."

Danny groaned, furrowing his eyebrows as a wave of nausea passed over him. He clutched at his aching chest and was surprised to feel more than one heartbeat. The teen sat up in a frenzy, only to discover that this action made his body shiver in pain.

"I ask that you calm down. It is not wise to sit up in your current state."

Danny's eyes flashed over to a boy, a merboy, with long chestnut hair and tan skin. His large eyes surveyed the merman in front of him with dismay.

"Great," Danny muttered, narrowing his eyes, "there's more of you."

Ignoring that comment, the boy announced with pride, "I am Mermando. What is your name?"

Danny held his side and clutched at the bed's sapphire-blue sheets. "Danny. Danny Fenton."

"That's hardly a merperson's name." Mermando shook his head, befuddled.

"Yeah, well, I'm technically a human."

Mermando laughed. "Impossible. How is it that you are sporting fangs and a tail?"

Danny scoffed. "How is it that you're in here when your father told you not to come near me?"

Mermando narrowed his eyes in suspicion. "How do you know about that?"

"I wasn't unconscious the entire time."

With an audible squeak, the metal doors were pushed open and slammed against the wall. In swam a tall, muscular merman, with dark skin and long brown hair. His eyes met Mermando's and flashed a terrifying golden color.

"Hey," Danny said, sensing the hostility, "he didn't do anything wrong. He was just curious."

"Curiosity killed the catfish, Mermando." The merman spoke directly to the swimming merboy, dismissing Danny with a wave of his large hand.

"Father, he's not violent. Sarcastic, yes, but it seems he's suffered some brain damage."

"I have not!" Danny shouted defiantly. "Look, there was this stream out in the woods, and my friends and I all swam in it and woke up like, like—" He gestured to his body.

"Like merpeople?" The father inquired.

"Not necessarily. Dipper was a deer, Wendy was a wolf, and Mabel was a—"

"Did you say Mabel?" Mermando's voice rose and he quivered in excitement. "Mabel Pines?"

"You know her?" Danny and the father said in unison, glancing at each other in confusion.

"Yes, well, she helped me escape from the town's pool!"

The father shook his head and continued. "How did you survive as a merman over water?"

"I was human when I first woke up, but—" Danny's head was suddenly filled with a sharp pain, as if thousands of small knives were pressed into his skull. He pushed his hands against his temples, muscles bulging from his neck as he strained to keep from screaming out.

Mermando and his father watched in horror as Danny's fangs elongated, his black scales climbing from his shoulders to his neck. Some tendrils even dared go over the teen's jawline and onto his cheeks. Danny's pupils shrunk into smaller slits, the iris becoming a bright greenish yellow. When the moment had finally stopped and the merteen dropped his hands from his head, he looked violent and hostile. However, Danny shook his head and continued on as if nothing had happened.

"Well, I guess there's no reason why I shouldn't tell you. You're merpeople, for crying out loud. Okay, so there was this lab accident, and I became half-ghost. When I tried to transform into my ghost half, I became this, but I couldn't change back. I've been getting worse ever since."

"Father, do my eyes deceive me?" Inquired Mermando, his eyes still wide in shock.

"No son, I saw it as well."

"What?" Danny asked. "Look, I know it's weird that I'm half-dead, but—"

"Mermando, please fetch this boy a mirror."

"Oh, God, what happened?" Danny asked. It was now his turn to widen his eyes in fear.

In a flash, Mermando returned with a small handheld mirror made of shells. He grabbed onto the handle and flashed it in his direction, only to gasp and drop it onto the bed.

"What do you think is going to happen?" Mermando whispered, his voice barely audible.

"I don't know, son, but I've seen this before."

"What is it?" Danny asked. "Please tell me it can be reversed."

"The last merperson this happened to, well, I had to lock her away. She's in the castle at Mexico. Violent and evil that merwoman is."

"What are you saying?" Danny inquired, leaning forward.

"I'm saying," the father sighed, "there is no known cure. If this keeps progressing, well . . ."

Danny sat, stock still, his eyes wandering to a spot on the wall.

He was going to become the person he had always fought against.

He was going to become evil.

[][][]

After spending quite a while attempting to pull Jazz away from the lakeside, she finally agreed to go back to the Shack and eat something before returning with supplies that were crucial for staying the night. There was no way she was going to leave Danny there, even though she hadn't seen him below the waves. She wondered what he was up to.

Wendy ate her hamburger quickly, occasionally glancing at Grunkle Stan. His white tank top was stained with grease.

"So, why is Taz human?" He inquired.

"It's Jazz, sir," Jazz muttered for the hundredth time. It was really starting to get on her nerves.

"We told you," Dipper set his fork down on the table, next to his bowl of salad, "she wasn't there. She just ran into us this morning."

"And she hasn't run for the hills?"

"Mr. Pines, you'd be surprised what I've seen back at home. Danny's transformation is nothing new."

Everyone leaned forward at once.

"You mean Danny has had this experience before? How did he fix it?"

Jazz's eyes widened. "I . . . Well, you see . . ."

Wendy growled. She let out a groan and doubled over, falling onto the floor. Her breaths were short and raspy. If not for the tense situation, Jazz would have been relieved. However, she dropped down next to her new friend in worry.

Grunkle Stan raced over, far too fast for someone his age. "Wendy, hey, are you alright?"

She growled in response.

"Maybe we should just leave her be . . ." Dipper trailed off, backing against the wall.

"Are you insane? She's your friend."

"Friend?"

Wendy sat up, eyes flashing red, and ran on all fours towards the door. Slowly but surely, her human half melted into her wolf half, and the teen glanced back and growled before breaking down the door and running into the night.

"Did she just go full-wolf?" Mabel asked, her eyebrows raising.

Grunkle Stan and Jazz stared at the door in worry. Would Wendy even come back?

Dipper hid underneath the table and shivered as a howl ripped through the air, rattling the windows.

"She just went full-wolf."