Mabel watched her brother until he was asleep. When she was sure he was out, she hopped up and grabbed his journal.

"Zombies, no," she muttered to herself. "Gnomes, ew. Cursed doors? Interesting. Here we go!"

She stared at the merman/mermaid page, her finger following the words she was reading.

"Behind the waterfall," she read, "there are herbs that can turn you into a mermaid/merman. Mix it with a drink, two for it to be temporary and four for permanent."

Mabel grinned from ear-to-ear.

"Soos!" Stan screamed. "Would ya take the kids down to the lake? A busload of tourists just arrived!"

"You got it, Mr. Pines!" Soos cried. Within ten minutes, Soos and the twins were in the golf cart.

"Why did you want to go?" Dipper whispered.

"Lemme see your journal."

He handed it to her and she flipped to the appropriate page. Dipper gasped. "Mabel! You can't be serious."

"Dipper, this is my chance to be with Mermando!"

"Temporarily, right?" When she hesitated, Dipper said again, "Right?!"

She sighed. "Yeah. Fine. But-"

"Mabel, be serious! You're just infatuated!"

"Like you with Wendy!"

"Shhh! That's different! I'm not abandoning my family for her."

"Dudes," Soos announced, "we're here. Do ya just want me to drop you?"

"Yeah," Mabel said, ignoring Dipper's glare. "Thanks."

"Anytime, hambone."

Despite the disagreement between them, Dipper agreed to come with Mabel in a rowboat to the waterfall. He assumed he could convince her otherwise by then.

"How could you even get to him?" he muttered as they rowed.

"He's been sending me messages in a bottle," Mabel explained. "So we planned this."

"What if he doesn't come?"

"He will."

"Mabel, come on, this isn't a good idea."

"He's my true love!"

"You said that about Norman!" Dipper cried. "He turned out to be a bunch of gnomes who wanted a queen!"

"Mermando isn't a bunch of gnomes."

Dipper quit rowing. "I'm not helping you run away from your family."

She groaned but ignored him. They were silent for the rest of the way there.

"I found it!" Mabel cried, picking the herbs. "Quick! Hand me the cup I brought!"

"No," Dipper muttered.

She sighed. "I only have two…"

He watched her upset expression, cursed himself for being so soft, and handed her the cup.

"Where are you meeting him?" Dipper asked.

"Here. The little area behind the waterfall."

She filled her glass, put the herbs in, and drank it.

"Feel any different?" Dipper asked.

She thought for a moment, then shook her head. "Maybe it takes-"

Mabel started to pass out and Dipper jumped to catch her. He carefully set her so she was sitting upright against the cave wall.

"Are you okay?" he demanded. She didn't answered. "Mabel! Wake up!"

Suddenly, her legs started to glow. Dipper jumped up and cried out in shock. He averted his eyes to the brightness, and when he looked back, she sat wide awake with a mermaid tail.

"Water!" she called hoarsely. "Roll me into… lake.…"

Dipper picked her up carefully and practically threw her in. She stayed below for a minute, then rose up, jumping majestically, splashing Dipper. Even in his sour mood he laughed.

"I'm a mermaid!" she cried. "Look, I've got a tail and everything!"

Dipper smiled. "So, when's Mermando getting here?"

"Mabel!" someone cried. Mermando swam under the waterfall and toward her. "You're here!"

She grinned. "Oh my gosh, you still have your crazy merman accent!"

He laughed as only he could. "It is Spanish."

Dipper shifted awkwardly. "Uh… so I guess I'll just be going to the 'Shack…"

Mabel didn't hear him. He sighed but climbed into his rowboat and back to the shore, promising Mabel he'd be back by midnight, when the herbs were supposed to wear off.