Is This Also a Rule?

During the day, the White Whale Town Aquarium sold tickets. At night, it turned off the lights.

During the day, children pressed their faces against the glass to watch tropical fish, and tapped lollipop sticks against the exhibition tanks until they echoed. Docents wearing blue bow ties stood beneath imitation coral arches and said, in syrup-sweet voices: In White Whale Town, there is an ancient legend—on the full moon, mermaids sit on the rocks and sing.

At night, the legend was locked underground.

By the time Lu Wenchao brought Coral inside, only the safety lights were on in the aquarium. A dim blue-green glow drifted through the corridors. On the walls, smiling mermaids were painted holding seashells, their tails curving in graceful arcs. Coral was blindfolded with black cloth and couldn't see them, but she could hear the water.

A lot of water.

Water boxed behind glass.

In the exhibition tanks, fish pressed against the glass, one after another, as if they had heard a tide sound that didn't belong here. They couldn't speak human language; all they could do was blow bubbles. But to Coral, the bubbles meant something: the water tasted bad, the lights were too bright, the man with the net was mean, and the big fish next door slammed into the glass three times a day.

Coral turned her head beneath the black cloth.

"Don't move," Lu Wenchao said.

His hand was on her shoulder—not too heavy, but just enough to keep her from swimming toward the tanks. She couldn't swim right now anyway. A silver net was still tangled around her tail fin, and her body was laid out on a wheeled transfer bed. Every time the wheels rolled beneath the bed, she felt like a long fish laid out on a cutting board.

"There are a lot of little fish here," she said.

"That has nothing to do with you."

"They say the water doesn't taste good."

The hunter pushing the bed stumbled.

Lu Wenchao paused too, then kept walking. "Don't listen."

"But they're saying it really loudly."

"Then pretend you didn't hear."

Coral thought about it seriously. "Do humans do that a lot?"

Lu Wenchao didn't answer.

They passed through the penguin pavilion, the beluga hall, and a shop packed with souvenirs. A row of plastic mermaid tails hung by the shop entrance—pink, blue, purple—swaying gently in the breeze from a fan. Coral couldn't see them, but she smelled a cloying rubbery odor and wrinkled her nose without meaning to.

"There are fake fish here."

One of the hunters snorted. "She can tell even with her eyes covered?"

"They don't smell like the sea. They smell like dried-out seaweed."

Lu Wenchao said quietly, "Shut up."

Coral immediately pinched her lips shut. Beneath the black cloth, her lashes were wet with rain and seawater, plastered against her cheeks, a little itchy. She wanted to scratch, but the net was still tangled around her, so she just had to bear it.

The transfer bed turned into the staff corridor. The fairy-tale murals on the walls disappeared, replaced by white tiles, iron doors, and surveillance cameras. Wind blew in from the depths of the hallway, carrying the smell of disinfectant, rust, stagnant water, and a faint fragrance. That fragrance was cold—not like flowers, not like the bioluminescent algae that bloomed on the ocean floor. It was more like something pretty that had been locked in a bottle.

Lu Wenchao swiped a card.

The iron door opened.

The elevator went down and down. Coral heard the electronic beep of the floor numbers changing. Each time it beeped, she was farther from the sea. Her tail fin started tapping anxiously against the edge of the bed. The silver net immediately tightened.

"Does it hurt?" Lu Wenchao asked.

"A little," she said honestly. "I don't like going down."

The hunter laughed. "A mermaid afraid of going down? Don't you all live at the bottom of the sea?"

"The bottom of the sea has the sound of the tide," Coral said. "There's nothing here. It's like a hole that can't breathe."

The laughter stopped.

The elevator doors opened. The underground pool appeared in the darkness.

The pool was far too small compared to the sea. Gray walls on all sides, cold white lights hanging overhead, a few plastic seaweed fronds floating on the surface. Observation windows were set into the pool walls, and beyond them were a control console and several rows of lockers. In the corner stood an old glass water tank. It was empty except for a faded label: Deep Sea Legends Exhibit — Under Maintenance.

Lu Wenchao removed the black cloth from her eyes.

Coral blinked several times before her eyes adjusted to the basement lights. First she looked at the pool, then the walls, then the plastic seaweed. Finally, enduring the pain in her tail, she politely nodded at the fronds of plastic seaweed.

The seaweed didn't move.

She waited a moment, then nodded again.

Still nothing.

"Fake?" Coral reached out in shock and pinched a plastic leaf. "Humans have to fake even seaweed?"

Someone by the door burst out laughing.

It was a young girl whose name tag read "Xiaoman." She was holding a clipboard, her short hair sticking up in every direction, her eyes round—like a manga character who'd just watched the protagonist leap off the page.

"You're really a mermaid?" Xiaoman crouched by the pool and lowered her voice. "What's your name?"

"Coral."

"Whoa." Xiaoman's eyes lit up even more. "That suits you. Your hair looks like moonlight over a coral reef."

Coral thought about it. "Does moonlight have hair too?"

Xiaoman was caught off guard, then burst out laughing. "It's a metaphor, a metaphor."

"A metaphor fish?" Coral immediately looked into the pool. "Where are the fish?"

Lu Wenchao stood by the door, his brow twitching.

Xiaoman laughed so hard she nearly dropped her clipboard into the water. She fished a transparent drinking straw out of her uniform pocket—she'd been about to drink her milk tea, but when she saw Coral staring, she handed it over. "Want to see this?"

Coral took it solemnly.

Transparent. Thin. Hollow. It looked a lot like the shed skin of a little sea snake from Tidewater Bay, or a tiny flute. She put the straw to her lips and blew hard.

The straw made a short, wailing sound.

Water splashed all over Xiaoman's face.

Xiaoman wiped her face and laughed so hard she crouched down on the floor. "That's for drinking, not for blowing."

Coral was deeply impressed. "Humans need such thin tubes to drink water? Are your mouths very small?"

Xiaoman opened her mouth as if to explain, then laughed too hard to speak.

Lu Wenchao said coldly, "Xiaoman. Out."

"I haven't done the intake paperwork yet."

"Out."

"But Lady Bai said to record the sample's initial condition."

"I'll write it."

Xiaoman gave him a skeptical look. "Brother Lu, last time you wrote a report, you spent three lines writing 'abnormally active.'"

Lu Wenchao stared at her.

Xiaoman immediately hugged her clipboard and shuffled out. Before she left, she secretly waved at Coral.

Coral copied her wave, and her tail swung underwater, splashing the pool loudly. Xiaoman's eyes sparkled so brightly she almost pulled out her phone to take a picture, but one look from Lu Wenchao sent her scurrying out.

The door closed. The underground pool fell silent.

Lu Wenchao took off his wet trench coat and hung it on the back of a chair. His black shirt clung to his shoulders and back, showing the tension in his muscles the whole way here. He didn't speak right away. Instead, he took a first aid kit out of a cabinet and pulled out a bottle of colorless medicine.

Coral floated at the edge of the pool, watching him carefully.

"Are you going to put my song in that box?"

"It's medicine."

"What's medicine?"

"Something that makes wounds heal faster."

"Why not just let them heal on their own?"

Lu Wenchao looked up. "Do your wounds in the sea listen to you?"

"Sometimes. When they don't, I sing to them."

"You're not allowed to sing here."

"Is that another human rule?"

"It's my rule."

Coral filed that away. She noticed that Lu Wenchao liked to divide things into "can do" and "can't do," but he never explained why. Her grandmother did that too—except Grandmother would smack her head with her tail, and Lu Wenchao didn't have a tail. He just smacked people with his eyes.

He bent down to examine the marks left by the silver net.

The moment his hand touched her tail scales, Coral flinched. She wasn't afraid of him, but the red welts from the silver net stung when the medicine touched them—like tiny sparks burrowing into the gaps between her scales.

Lu Wenchao stopped moving.

"Does it hurt?"

"A little," Coral said honestly. "But you already took away the welcome mat, so I'm not mad."

"That's called a hunting net."

"Hunting net." She repeated the word carefully, like she was learning an important new term. "Is it for catching friends?"

Lu Wenchao's hand froze in midair.

The basement lights hummed with a faint electrical buzz. The water's surface reflected his face—cold, tired, and carrying a hint of exasperation at being questioned by her.

"No," he said.

"Then for catching enemies?"

He poured the medicine into a small trough at the edge of the pool. The liquid dispersed into the water through the circulation intake. The red welts left by the silver net gradually faded.

"For catching cargo."

Coral looked down at herself.

She didn't quite understand what "cargo" meant, but it didn't sound like "friend" or "guest." She wanted to ask if cargo could go home, but the look on Lu Wenchao's face told her that question wouldn't get a good answer right now.

She asked a different one instead.

"When are you going to put me back in the sea?"

Lu Wenchao screwed the cap back onto the medicine bottle. "When I figure out why you know Lu Qi."

"Lu Qi." Coral repeated the name. "What is he to you?"

Lu Wenchao looked up.

The coldness in that look made Coral immediately hide the tip of her tail behind the plastic seaweed. The plastic seaweed was stiff and uncomfortable against her tail fin, but at least it felt like something was shielding her.

"Don't be afraid of me," she said quietly. "I won't tell your secret to a bad sea urchin."

Lu Wenchao frowned. "Bad sea urchin?"

"A secret that pricks people."

He looked at her, like he was about to say something.

Then, from outside the door, came the sound of high heels.

One step.

Another step.

Slow, clear—like someone tapping pearls against bone.

The air in the basement turned cold and fragrant. That same scent Coral had smelled in the corridor crept in first, and then the door opened.

Lady Bai walked in.

She wore a pearl-colored long dress, her hem not a drop wet. The pearl earrings at her ears swayed gently under the lights. Her gloves were as white as if they'd never touched anything dirty. When she saw Coral in the pool, there was no surprise in her eyes, no fear—only the satisfaction of finally receiving a long-awaited acquisition.

Coral didn't like that look.

In Tidewater Bay, when the clan found a pretty shell, they would be delighted, would praise it, would trade stories about it. But Lady Bai looked at Coral like she was looking at a glass bottle that had already been priced.

"Dear." Lady Bai bent down at the edge of the pool, her voice warm as hot milk. "Welcome to White Whale Town."

Coral relaxed. "You say welcome too. So the net really is a welcome mat."

Lady Bai's smile deepened. "How adorable."

Lu Wenchao stepped between her and the pool. "The sample is unstable. No examination tonight."

"Sample." Coral repeated the word softly, then looked down at herself. That word and "cargo" were alike. Neither of them sounded like a name.

Lady Bai ignored her confusion. Her gloved fingertip tapped the edge of the pool—once, twice—as if testing the quality of the glass.

"I heard she sang a song," Lady Bai said. "Shattered all the lights. The more unstable she is, the more she needs to be examined."

"She's just left the sea. Forcing examination will kill her."

"Even dead has its price," Lady Bai said, her tone still gentle. "But alive is worth more."

Coral didn't fully understand.

But she understood "die."

She looked at Lu Wenchao. His jaw was tight, his hands at his sides, close to the silver hook. The same hands that had loosened her silver net and poured her medicine had now become a hunter's hands again.

From outside the door came the sound of wheels rolling.

Xiaoman and two staff members pushed a transparent water tank into the room. The tank was much smaller than the underground pool. Its bottom was lined with fine white sand, and a few strands of silver-gray algae floated on the surface. The algae looked soft, like hair in moonlight—but the moment it appeared, Coral's tail fin began to go numb.

She instinctively backed away.

The pool wall stopped her.

"What is that?" she asked.

Lady Bai smiled. "Something to keep you calm."

"I'm already very calm." Coral immediately pinched her lips shut and nodded emphatically.

Xiaoman's face went pale. She gripped her clipboard so hard her knuckles turned white. "Madam, do we really have to do this tonight? She just—she doesn't look like she's in good condition."

Lady Bai looked at her.

Xiaoman seemed to have a switch flipped inside her. She immediately fell silent.

Lu Wenchao pressed his hand against the silver hook. "I said, not tonight."

Lady Bai sighed softly.

Even her sigh was beautiful, as if she were truly sorry about a small inconvenience.

"Wenchao," she said. "Your father used to like saying 'no' too. No, shouldn't, can't. And then he never got a chance to speak again."

The water in the underground pool suddenly went cold.

Coral looked at Lu Wenchao. She didn't understand the twists and turns of human threats, but she saw his fingers turning white from the force of his grip. It wasn't just anger. It was more like someone had driven an old hook back into his body.

She swam to the edge of the pool and whispered, "Is this also a human rule?"

Lu Wenchao didn't look at her.

Lady Bai raised her hand.

The two hunters opened the tank lid.

The scent of the silver algae immediately dispersed. It wasn't like ordinary seaweed—ordinary seaweed smelled of salt, of mud, of places where small fish had hidden. The silver algae had no smell of life at all, only a sharp coldness, like thin needles piercing the throat. Coral's tail fin went so numb she could barely lift it, and her voice got stuck in her throat.

"Put her inside," Lady Bai said.The hunter's hand reached toward the pool water.

Xiaoman stepped half a pace forward but was pulled back by a staff member beside her. Her eyes were red with anxiety, yet she could only whisper, "Brother Lu..."

Lu Wenchao pulled out the silver hook.

The sound of metal echoed through the basement. Both hunters stopped at once.

Madam Bai looked at him, her smile fading slightly. "You'd raise a hand against me over a specimen?"

Lu Wenchao did not answer.

Shanhu stared at the silver hook. It was as bright as the net, but far more dangerous. She suddenly realized that if Lu Wenchao acted, blood would spill. Human blood was red water—she had already seen a little of it on the boat. Red water flowing out must hurt.

She didn't want him to hurt.

The thought came from nowhere. He had caught her, called her cargo, barked at her to shut up. But he had also loosened the net, poured medicine for her, and stepped in front of her when Madam Bai said, "Even dead, she still has a price."

Shanhu didn't understand humans.

She only knew she couldn't let this basement, where no tide sounded, grow any colder.

She thought of the sleeping person deep in the sea.

Lu Qi.

He had taught her a song in the Black Tide. Back then, she was still small, secretly swimming into the deep trench her clan forbade, hearing someone cough behind a door. She asked if he was lost. The man didn't answer, only hummed a low melody.

He said, if the lights on the shore were too harsh, sing to them.

Shanhu asked then: Would the lights listen?

He said: No, but they would be afraid.

Now, the lights in the basement were too harsh.

The silver algae was also too harsh.

Madam Bai's smile was even harsher.

Shanhu took a deep breath.

Lu Wenchao sensed something wrong and whirled around. "Don't sing."

Too late.

The first thread of song slipped from Shanhu's throat.

It was very soft—not like the legendary siren songs that could make sailors jump into the sea, nor the saccharine melodies imagined by humans on stage. It was more like a seashell turned over by the tide, revealing a sliver of light not yet dried by the sun. The sound spread from the underground pool, touching the gray walls, touching the glass, touching the transparent tank.

The light bulbs flickered at once.

Madam Bai's smile froze.

The silver algae in the tank stiffened, like a swarm of snakes hearing a summons. They no longer floated gently but strained taut toward Shanhu's direction. A faint crack came from the tank glass.

"Stop." Madam Bai's voice dropped for the first time.

Shanhu did not stop.

In truth, her singing was unsteady. She was too far from the sea, her tail fin still ached, her throat was numbed by the sting of the silver algae. Several notes were off-key, and she even sang the melody Lu Qi had taught her half a beat wrong.

But when those wrong notes collided with the light, a figure suddenly appeared in the basement.

Very faint, a mere flicker in the reflection of the tank.

A man in an old hunter's uniform stood behind Shanhu, half his body as if soaked through by the Black Tide, and spoke in a low voice.

"Don't let the Rending Tide be heard again in White Whale Town."

Lu Wenchao's face changed instantly.

The next moment, the silver algae inside the glass tank burst apart, fine specks of silver splashing against the tank walls.

Pop.

The first light shattered.

Then the second, the third, the fourth.

Darkness crashed down in pieces. Someone screamed in the basement; Xiaoman crouched clutching her record board; the hunters stumbled backward in panic. Madam Bai's pearl earrings glinted in the dark, reflecting her eyes that had finally lost control.

Lu Wenchao rushed to the edge of the pool and grabbed Shanhu's shoulder.

"Stop!"

The song broke off.

The last bulb swung overhead, as if hesitating whether to keep living.

Shanhu looked up at it and whispered, "Sorry, I think I sang it wrong."

Pop.

The final light exploded too.