Underwater

When the Dubh-Loch Beast's tentacle burst out of the silt, Zhang Wen's mind only had time to process one thing—

Artoria's hand was gripping his shoulder and dragging him backward.

She pulled hard. Zhang Wen was yanked three meters through the water, and the fang nearly slipped from his hand.

He steadied himself and looked back at where he had been.

The tentacle was as thick as an arm, pitch-black from end to end, its surface covered in a slimy substance. It had erupted from the silt at the bottom of the lake and struck precisely where Zhang Wen had been a second earlier.

If Artoria had pulled him half a second later—

Don't think about that.

"It's beneath the stone," Zhang Wen said quietly through the Communication Lens.

"I saw it." Artoria was already standing in front of him, Excalibur held across her body. Invisible Air still worked underwater—though the blade itself could not be seen, the compressed air distorted the currents around it slightly.

The tentacle withdrew.

Then the lakebed began to tremble.

Silt churned. Rocks rolled. A massive shadow emerged from the murky water ahead.

The Dubh-Loch Beast.

At last, Zhang Wen saw its full form.

It had no fixed shape—Dagworth's manuscript had been right. Its entire body resembled a mass of flowing black gel, roughly four or five meters long, its width constantly changing. Bubbles continuously rose from its surface, each one releasing a small burst of black liquid when it popped.

Corrosive bodily fluid.

Its "head"—if that largest bulge could be called a head—had two dim crimson points of light on it. They did not resemble eyes so much as two flames embedded in jelly.

It emitted a low vibration. Not a cry, but an infrasonic wave produced as the trembling of its entire body traveled through the water. Zhang Wen felt pressure in his chest—the infrasound was affecting his internal organs.

"Twenty meters away," Artoria's voice came through the lens. "It's coiled above the stone."

Just as the manuscript had said—the Dubh-Loch Beast instinctively guarded the source of its magic.

After Old Nott's remote control had been severed, the Dubh-Loch Beast had indeed entered a brief period of confusion. Its movements had slowed, and the two dim crimson lights flickered unsteadily.

But the confusion was fading.

It had noticed the intruders.

"The window is closing," Zhang Wen said. "I need to get close to the stone."

"I'll clear a path."

Artoria did not wait for his reply.

She charged forward.

Artoria was slower underwater than on land—she had said so herself, that she was only one-third as efficient underwater. But even one-third of the King of Knights was still something no creature wanted to face.

Excalibur swung.

Invisible Air's wind pressure formed a high-speed current in the water—though it was less powerful than on land, it was enough to tear a half-meter-long gash across the Dubh-Loch Beast's surface.

Black bodily fluid poured from the wound.

The water immediately turned a murky, inky black.

The Dubh-Loch Beast shuddered—far more violently than before. The infrasonic impact made Zhang Wen's scalp tingle.

It was enraged.

Six tentacles extended from its body at once, lunging at Artoria from different angles.

Artoria spun through the water and severed three tentacles in rapid succession. Black fluid sprayed from the cut ends. The remaining three bypassed her front and closed in from the sides and rear.

She blocked one with her sword, twisted away from the second—

The third tentacle grazed her left arm.

The metallic coating of the Iron Armor Charm hissed. When the black fluid touched the iron surface, it produced a cloud of pungent smoke.

The corrosion had begun. But the iron coating held. One layer had been eaten away, exposing the fabric beneath, but it had not reached her skin.

"The Iron Armor Charm on my left arm has weakened by roughly thirty percent," Artoria reported. "It can still hold."

"Don't take it head-on! Your job is to hold it off, not fight it directly!"

"I know."

She knew, but she was still fighting it head-on.

Because Zhang Wen needed time to reach the stone. And the only way to buy him that time was to draw the Dubh-Loch Beast's full attention onto herself.

Zhang Wen gritted his teeth and, while the Dubh-Loch Beast focused on Artoria, circled toward the stone from the side.

The water was murky. The bodily fluid sprayed by the Dubh-Loch Beast had dyed the surrounding lakewater black as ink. Visibility had dropped from three meters to less than one.

Zhang Wen navigated with the Tracking Crystal fragment on his wand. Purple light guided him onward.

Five meters.

Three meters.

Two meters—

He saw the stone.

The black stone was embedded in the silt, and the soil around it had been entirely corroded into black gel.

Zhang Wen tightened his grip on the Basilisk Fang.

He swam directly above the stone.

Adjusted his angle.

Raised the fang—

The Dubh-Loch Beast suddenly emitted a shudder unlike any before.

The entire lakebed shook.

It sensed someone approaching its core.

Two tentacles shot directly from the bottom of the Dubh-Loch Beast's body—bypassing Artoria—and lunged at Zhang Wen at tremendous speed.

"Zhang Wen! Behind you!" Artoria's voice exploded through the lens.

Zhang Wen had no time to turn around. In the corner of his eye, reflected in the hand mirror, he saw two pitch-black tentacles closing in from diagonally behind him.

He made a decision—

He would not dodge.

Strike.

The Basilisk Fang stabbed viciously into the surface of the black stone.

The stone let out a piercing shriek—not a physical sound, but a resonance produced by rupturing magic. The fang sank roughly two centimeters into the stone. Cracks spread outward from the point of impact.

But it did not shatter.

The stone was harder than he had expected. The fang had pierced it, but only created cracks; it had not broken through completely.

It needed a second strike.

The tentacles arrived.

Zhang Wen did not have time to pull out the fang and strike again—he released it, rolled over, and reinforced himself with an Iron Armor Charm.

The first tentacle struck him in the back.

The impact hurled him two meters away. The Iron Armor Charm blocked the corrosion, but the shock traveled from his back through his entire body. His spine felt as though someone had struck it with an iron hammer.

The second tentacle swept toward his waist—

A flash of sword light cut in from the side.

Artoria.

He did not know when she had moved to his side. Excalibur precisely severed the second tentacle. Black fluid from the severed end spread through the water.

"Are you hurt?" she asked as she blocked newly grown tentacles.

"No. The Iron Armor Charm blocked it. But the fang—"

Zhang Wen looked toward the stone.

The Basilisk Fang was still lodged in the stone's surface. The cracks were slowly expanding—the venom was continuously corroding the stone's internal structure—but it was too slow.

"The fang is stuck in the stone. We need a second one to speed up the destruction."

"You have another."

"Yes. But the Dubh-Loch Beast won't give me another chance to get close."

The Dubh-Loch Beast had indeed learned. Its body was moving toward the stone, using its entire gelatinous mass to cover the space above it. Tentacles extended from every direction, forming a dense barrier.

Anything that tried to approach the stone would be intercepted by the tentacles.

"We need to lure it away," Zhang Wen said.

"Where?"

"The shallows. If we can lure it to an area less than three meters deep, sunlight can weaken it. The manuscript said it repels sunlight."

"It's overcast today."

Zhang Wen looked up—through twelve meters of lakewater and the Bubble-Head Charm, the sky was indeed gray and gloomy.

"...Forget the sunlight plan."

"Fire," Artoria said. "It fears fire."

"Starting a fire underwater?"

"Can you create fire underwater?"

Zhang Wen thought for three seconds.

"Yes. But—it requires concentrated magic, and the range is limited. A Flame Charm underwater can last no more than five seconds."

"Five seconds is enough. You create fire and drive it away. I'll rush over and stab the second fang into the stone."

"You'll do the stabbing?"

"Your Iron Armor Charm has already been partially worn down. You may not withstand another hit from a tentacle. My Iron Armor Charm and physical constitution are both stronger. It makes more sense for me to approach the stone."

Zhang Wen wanted to argue.

But he could not. She was right.

"Give me the fang." Artoria held out her hand.

Zhang Wen took the second—and last—Basilisk Fang from the iron box at his waist and placed it in her palm.

The fang looked tiny in her hand. Her fingers closed around it, steady and firm.

"I'll count to three." Zhang Wen raised his wand and aimed at the Dubh-Loch Beast. "One—"

The Dubh-Loch Beast's tentacles continued to extend. The currents along the lakebed grew more and more chaotic.

"Two—"

Artoria adjusted her position, poised to move.

"Three."

Zhang Wen cast with all his strength.

"Blazing Fireball—"

An orange-red fireball erupted from the tip of his wand.

Casting a Flame Charm underwater was extremely difficult—water absorbed heat, cut off oxygen, and extinguished flames. But magical fire could burn without oxygen. Zhang Wen poured nearly all his remaining magic into this strike.

The fireball expanded underwater.

The temperature surged. Zhang Wen could feel the water ahead boiling—bubbles churned wildly.

The fireball shot toward the Dubh-Loch Beast.

The Dubh-Loch Beast reacted far more violently than expected.

Its entire body contracted sharply—as though it had been scalded—and every tentacle retracted into its body at once. Its gelatinous mass sprang away from above the stone and retreated from the flames.

The stone was exposed.

Artoria moved.

Even at only one-third of her land speed, her underwater dash was still so fast that Zhang Wen saw only a blurred shadow.

Three meters. Less than a second.

She reached the space above the stone.

Her right hand rose high. The tip of the Basilisk Fang aligned with the cracks caused by the first fang—an aim precise to the millimeter.

She drove it down.

The fang sank into the stone.

A full three centimeters.

The stone let out an even sharper shriek than before. Cracks burst outward in every direction from the point of impact. Its black surface fractured, revealing the dark crimson core within—

The core was trembling. Breaking apart.

The venom from two Basilisk Fangs was corroding the stone's internal structure at the same time. Dark magical energy overflowed wildly—the lakewater became blacker and murkier, and the temperature plummeted.

The Dubh-Loch Beast sensed that the source of its life was being destroyed.

It let out a true howl—not infrasound anymore, but a high-pitched screech that pierced through the water. It was unbearably shrill. Even Zhang Wen's Bubble-Head Charm trembled.

It spun around and charged back.

Its speed surged. It had gone berserk, having lost all reason.

All its tentacles shot out—not probing attacks anymore, but full-force strikes without regard for cost.

Artoria was still crouched beside the stone—making sure the fang had been driven in completely.

"Go!" Zhang Wen shouted.

Artoria released the fang and retreated.

But the Dubh-Loch Beast was too fast.

In its berserk state, it was nearly twice as fast as before. Four tentacles closed in from four directions at once, forming a cage-like encirclement.

Artoria severed two. She blocked the third with her blade—but the impact pushed her back more than a meter.

The fourth tentacle coiled around her left ankle.

"—!"

The corrosive bodily fluid instantly began eating away at the Iron Armor Charm's coating. White smoke rose from Artoria's left ankle.

She glanced down without hesitation—then swung Excalibur backward and severed the tentacle wrapped around her ankle.

But the remaining section was still coiled around her. The black liquid had already eaten through the Iron Armor Charm's coating and was reaching her boot.

Zhang Wen charged toward her.

He cast a Freezing Charm with his wand—"Flash Freeze"—and the severed tentacle instantly froze, falling away from Artoria's ankle.

"How's your ankle?"

"This section of the Iron Armor Charm is ruined. The boot's outer layer was corroded. The skin is fine."

"Are you sure?"

"I'm sure."

Zhang Wen glanced at her ankle. A palm-sized black scorch mark had been burned into the boot's outer layer, but the Inner Layer was intact.

There was no time to inspect it further. The Dubh-Loch Beast was already regrouping for another attack.

But its movements had clearly slowed.

The cracks in the stone were still spreading. The venom was still working. The Dubh-Loch Beast's magical supply was weakening.

"It's getting weaker." Artoria had noticed it too.

"The fangs are continually damaging the stone. But it'll take time before it completely shatters—"

"How long?"

Zhang Wen looked at the stone. Cracks already covered roughly two-thirds of its surface. The dark red glow in its core flickered faster and faster, like a failing heart.

"Ten to fifteen minutes."

"We need to hold out for fifteen minutes."

"Hold out for fifteen minutes against a rampaging Dubh-Loch Beast."

"Underwater."

"Right. Underwater."

They looked at each other for a second.

Inside the Bubble-Head Charm, the corner of Artoria's mouth lifted slightly.

A smile in the middle of battle.

At that moment, Zhang Wen suddenly thought—this woman was really beautiful.

The thought lasted perhaps three-tenths of a second before he forcibly crushed it. Getting distracted on a battlefield meant death.

"Back-to-back," Zhang Wen said.

Artoria nodded.

The two floated back-to-back above the stone. Artoria held her sword toward the Dubh-Loch Beast's front, while Zhang Wen covered the rear and flanks with his wand.

The Dubh-Loch Beast extended its tentacles again. This time, there were eight—more than before, but each was thinner and slower.

Its magic was fading. It was using its last strength to protect the source of its life.

Artoria cut down four tentacles in front of her. Her movements were clean and decisive.

Zhang Wen alternated between the Disarming Charm and the Freezing Charm, driving back three tentacles behind them. The fourth stabbed in diagonally from the right—

"Right side," Artoria warned.

Zhang Wen twisted aside, freezing the tentacle with a Freezing Charm at the same time. The frozen tentacle lost its vitality and slowly sank through the water.

"Thanks."

"You're welcome. Two more are coming from your three o'clock."

Zhang Wen turned to deal with them.

The two worked together with growing coordination. Artoria handled broad sweeps across the front, while Zhang Wen delivered precise strikes against the sides and rear. Her swordsmanship covered a wide area; his spells were accurate. One was fierce, the other precise.

Five minutes passed.

The Dubh-Loch Beast's tentacle attacks dropped from eight to ten times a minute to five or six. Its body was shrinking too—from four or five meters down to roughly three and a half.

The cracks in the stone continued to spread. The red glow in the core flickered faster and faster.

Ten minutes.

The tentacle attacks dropped to two or three times per minute. Its body had shrunk to three meters. Gray patches began to appear across its black gelatinous surface—a sign of degeneration.

"It's withering," Zhang Wen said.

"Keep going."

Twelve minutes.

The Dubh-Loch Beast's body suddenly convulsed violently.

Then—

A dull cracking sound rose from the lakebed.

The stone shattered.

Two Basilisk Fangs had pierced through the stone's entire core. The dark red light vanished. Fragments scattered through the water, turning into ordinary gray stone chips.

The dark magic ebbed from the lake water like a receding tide.

The Dubh-Loch Beast stopped.

All its tentacles ceased moving at once. The two dark red points of light—its "eyes"—began to dim.

Its body was collapsing. The gelatinous surface lost its sheen and turned into dull gray, semi-transparent matter. Its size visibly dwindled—three meters, two meters, one meter—

In the end, it shrank into a gray lump about half a meter wide. It slowly sank through the water and settled beside the shattered remains of the stone.

It did not move again.

Zhang Wen stared at the thing for ten seconds.

"Dead?"

"Degenerated," Artoria said. "Without its source of magic, it reverted to its primitive form."

Zhang Wen scanned it with his wand. Dark magic reading—zero.

Completely zero.

"It's over," Zhang Wen said.

His voice echoed faintly inside the Bubble-Head Charm.

The two of them rose toward the surface.

Three meters. Five meters. Eight meters. The light gradually brightened, and the water cleared.

The surface drew closer and closer.

Zhang Wen's head broke through the water.

Cold air flooded into his Bubble-Head Charm. He lifted the spell and took a deep breath—

Air. Fresh, freezing Scottish Highlands air.

He had never thought air could smell so good.

Artoria surfaced beside him. Her wet golden hair clung to her cheeks. After releasing the Bubble-Head Charm, she took a deep breath as well—only a small one, but Zhang Wen noticed.

She was tired too.

They swam to shore. Zhang Wen climbed up first, then reached out to pull Artoria up.

Her hand clasped his.

Wet and cold, but her grip remained strong.

Zhang Wen pulled her onto the shore.

The two stood by the lake, soaked to the bone. November's cold wind cut through their wet clothes like knives.

Zhang Wen immediately cast a Drying Charm and a Warming Charm. Artoria first, then himself.

"Your ankle." He crouched down to inspect her left ankle, where the tentacle had corroded it.

The boot's outer layer had indeed been burned through. But after taking it off and checking—her skin was intact. The remaining coating of the Iron Armor Charm had blocked all the corrosion.

"I told you my skin was fine," Artoria said.

"It only counts once I've confirmed it myself."

Zhang Wen ran his fingers around her ankle, checking it thoroughly. Her skin was smooth and unbroken, without the slightest trace of burns or corrosion.

"Pass," he said, standing up.

Artoria looked at him.

Her hair had not fully dried yet—the Drying Charm needed several more casts on thoroughly soaked long hair. Golden strands clung to her cheeks and neck, framing her reddened skin.

"Are you all right?" she asked.

"A hit on the back. It hurts a little, but the Iron Armor Charm blocked it."

"Let me see."

Zhang Wen hesitated.

Artoria stepped behind him and directly lifted the back of his robe.

"Hey—"

"Be quiet."

Her fingers pressed against the spot on his back where the tentacle had struck. There was no external wound, but a swollen red patch—blunt trauma from the impact.

"Bruising. Nothing serious. Have Madam Pomfrey take a look when we get back."

"Is your diagnosis as reliable as hers?"

"At Camelot, I treated more battlefield injuries than she has seen in her entire life."

"...All right."

Artoria lowered the hem of his robe. Her fingers lingered on his back for about a second—not to inspect the injury, because the examination was already over.

There was no medical reason for that second of contact.

Zhang Wen felt that second make his heart race faster than the entire battle had.

"Professor Zhang!!"

Harry came sprinting down the gentle slope on the north shore. The rooster in the cage behind him clucked as it was jostled around.

"Are you all right?! The lake was bubbling just now—then there was this huge wave—and then it suddenly went calm—"

"It's over," Zhang Wen said. "The Dubh-Loch Beast has degenerated. The stone was destroyed."

Harry's eyes went wide.

"Really?!"

"Really."

Harry let out a long breath. Then he broke into a grin.

"Great."

Zhang Wen opened Line A on the Communication Lens.

"Headmaster Dumbledore. Line B operation complete. The cursed stone has been destroyed. The Dubh-Loch Beast has degenerated, and the threat has been eliminated."

Three seconds later.

"Well done." Dumbledore's voice was calm but smiling. "On Line A—Old Nott has been handed over to Alastor Moody. I'm on my way to Glenmore Lake."

"There's no need. It's already over."

"I'd still like to come and see. An old man's curiosity."

Five minutes later, Dumbledore appeared by the lake.

He wore a purple traveling cloak and carried a bag of Lemon Sherbet in one hand.

"Post-battle snacks." He handed the bag to Zhang Wen. "After every battle, one needs to replenish one's sugar."

Zhang Wen accepted the bag. Eating Lemon Sherbet in Scotland in November was practically torture—but Dumbledore's kindness could not be refused.

Artoria took two pieces without hesitation.

Eating Lemon Sherbet just after coming out of five-degree lake water. The King of Knights' stomach probably possessed legendary resistance too.

Dumbledore walked to the lakeshore and scanned the water with his wand.

"The lingering dark magic has fallen to a negligible level," he said. "The lake will naturally purify itself in a few weeks. The ecosystem will likely need six months to a year to recover."

"Angus's sheep won't disappear anymore," Zhang Wen said.

"They certainly won't." Dumbledore smiled. "The two of you have done something remarkable."

His blue eyes turned toward Zhang Wen and Artoria.

"Two people. Underwater combat. Destroying an adult Dubh-Loch Beast in twelve minutes." His tone held genuine admiration. "I had originally thought you would need at least twenty."

"She's fast." Zhang Wen pointed at Artoria.

"He found the stone's exact location," Artoria said.

Dumbledore looked at Zhang Wen, then at Artoria, and his smile widened a little more.

He said nothing.

But Zhang Wen felt the headmaster's gaze carried the expression of I saw everything, but I've chosen not to say anything.

Very Dumbledore.

Before returning, Zhang Wen went to Angus's house.

Angus stood at the door, nervously rubbing his hands together. When he saw Zhang Wen approach, his expression shifted from anxiety to expectation, then disbelief.

"It's solved?"

"It's solved. The stone was destroyed, and that thing degenerated. Your lake is safe."

Angus opened his mouth, then closed it. Closed it, then opened it again.

Then the Scottish old man in his seventies grabbed Zhang Wen's hand and gave it a firm shake.

"Thank you, lad." His voice was slightly hoarse. "Thank you."

"You're welcome. If anything strange happens again in the future—"

"I know. I'll find you."

Zhang Wen nodded.

As he left Angus's house, he looked back at Glenmore Lake.

The gray lake rippled softly in the cold wind. No black foam, no strange smell, no terror lurking beneath the water.

Just an ordinary lake in the Scottish Highlands.

Quiet. Ordinary.

It should have been this way from the start.

By the time they returned to Hogwarts through Floo Powder, it was already evening.

Zhang Wen went to the Hospital Wing to have Madam Pomfrey examine the blunt injury on his back. It was nothing serious—a layer of purple ointment made the pain vanish immediately.

"You young people never take your bodies seriously," Madam Pomfrey grumbled.

"I value my body very much. The proof is that I came to you for an examination."

"What about Miss Pendragon? Was she hurt too?"

"The Iron Armor Charm around her ankle was corroded, but her skin wasn't injured."

"Have her come in for an examination too."

"You should tell her that. She might not be very willing—"

"Willing or not." Madam Pomfrey's tone allowed no refusal. "Come."

When Madam Pomfrey intercepted Artoria in the corridor, the expression on her face was quite a sight—

The King of Knights, who had once faced the Basilisk without changing expression, was forced into the examination room by a middle-aged witch from the Hospital Wing using the line, "You must come for an examination, or I'll tell Dumbledore."

Zhang Wen waited outside.

Five minutes later, Artoria came out.

"The result?"

"She said I was perfectly healthy. Then she made me drink some kind of potion. It tasted very bitter."

"A nutritional supplement. Madam Pomfrey's standard procedure. Everyone who comes in has to drink a cup."

"You drank it too?"

"I did."

"Did you think it was bitter?"

"Extremely bitter."

"I thought it was extremely bitter too."

The two walked side by side down the corridor toward their office.

Their wet clothes had already been treated with a Drying Charm, but their hair still carried a faint scent of lake water—a mixture of mud and aquatic grass.

When they reached the third floor, Zhang Wen stopped.

"Artoria."

"Yes?"

"What happened in the water today—when you pulled me—if you'd been half a second later—"

"I wasn't late."

"But if—"

"There is no if." Artoria turned to face him. "I promised I would stand in front of you. I did."

Zhang Wen looked at her.

The corridor was quiet. Firelight fell across her profile. Her golden hair had dried and returned to its soft, fluffy state. Her cheeks still held a faint flush from the underwater battle—perhaps from the cold water, or perhaps from warming up after the Drying Charm.

"You did too," Artoria said. "You promised you would come back alive. And you came back."

A pinky promise.

"A pinky promise," Zhang Wen said.

The corners of Artoria's lips rose—this time by such a wide margin that even Neville Longbottom would not have needed any powers of observation to notice it.

"Mm," she said. "A pinky promise."

The two continued onward.

The office door opened. The fireplace was still burning. The previous battle plans and maps lay scattered messily across the desk.

Artoria went to the kitchenette and began boiling water for tea.

Zhang Wen sat down at the desk and tidied up the documents.

Then he opened a new notebook.

He turned to the first page and wrote a line:

"Glenmore Lake Incident—case closed."

He drew a line beneath it.

Below the line, he wrote another sentence in small letters, then crossed it out after finishing.

The crossed-out sentence read:

"She smiled. She looked beautiful."

He had crossed it out. But the ink remained.

When Artoria came over carrying two cups of tea, Zhang Wen quickly shut the notebook.

"What are you writing?"

"The case report."

"That quickly?"

"It's only one line. 'Case closed.'"

Artoria set the tea in front of him. Then she stood beside the desk and lowered her eyes to look at the closed notebook.

Her eyesight was several times sharper than that of an ordinary human.

Zhang Wen suddenly realized—with her eyesight—she had most likely seen what he had written and crossed out while walking over.

He did not dare look up.

"Black tea. Two spoonfuls of sugar," Artoria said. "Drink it while it's hot."

Then she carried her own tea to the window.

Zhang Wen watched her back.

She sat on the windowsill, holding her tea in one hand while the other rested on her knee. Her gaze was fixed on the twilight outside.

Very calm.

As calm as she always was after every battle.

But Zhang Wen noticed the hand holding her tea—her little finger was slightly raised.

It was not proper tea-drinking etiquette.

It was the same little finger she had raised during their pinky promise yesterday.

An unconscious repeated gesture.

Zhang Wen picked up his tea and took a sip.

Two spoonfuls of sugar. The temperature was just right.

The sky outside gradually darkened. November at Hogwarts brought another peaceful night.

The Dubh-Loch Beast was gone.

The stone had shattered.

Old Nott had been captured.

Glenmore Lake had returned to peace.

But Zhang Wen felt that something had just begun.

Not a threat.

Something else.

He could not name it.

But he felt that it was warm.

About as warm as the tea.

And about as warm as her body temperature.