Chapter Text
The slender, hand-copied manuscript felt heavier in Yanxuan’s hands than the finest Yunmeng steel. As she walked away from the misty back hills, the low, comforting hum of Lan Xichen’s Liebing faded, replaced by the crushing reality of her daily training.
For the next three days, Yanxuan became a ghost within the Cloud Recesses. During the mandatory morning drills on the main training grounds, she forced herself through the motions. She watched Jiang Cheng move with explosive, terrifying precision—his blade cutting the air with the sharp, crackling intent of a summer storm, desperate to catch the eye of the stone-faced Lan elders.
"Lean into the strike, A-Xuan!" Jiang Cheng snapped during a sparring pause, wiping sweat from his brow. "You're dragging your heels. The Jiang style doesn't hesitate. It pierces."
"I know," she lied quietly, her mind wandering to the loose floorboard in her room where Xichen’s papers were hidden.
She couldn't tell him that every time she tried to summon that jagged, sudden burst of spiritual pressure, her golden core didn't explode—it shivered. It was a cello string trying to act like a lightning bolt.
Her real work began at midnight. While the rest of the guest disciples slept soundly under the strict Lan curfew, Yanxuan snuck into the deep, vertical bamboo groves flanking the cold springs. Under the pale, unfiltered moonlight, she spread Xichen’s manuscript on a flat rock.
The text was a revelation of physics and spiritual anatomy. Where her mother, Madam Yu, demanded rigid, unyielding discipline, Xichen’s notes spoke of fluidity. She memorized the charts detailing how air resistance changes based on the angle of a blade's flat, and how human meridians can act as acoustic chambers.
She drew her standard Jiang sword. It was balanced for hacking and piercing, its weight concentrated toward the upper third of the blade. When she closed her eyes and let her core vibrate naturally, the heavy steel shook erratically in her grip, fighting her.
“Do not command it to stand still,” Xichen’s voice echoed in her mind. “What you call 'scattering' is actually resonance.”
Taking a deep breath, Yanxuan relaxed her wrist. She stopped trying to thrust. Instead, she allowed the erratic vibration of her energy to ripple down her arm, mapping the frequency to the blade. She swept the sword in a slow, continuous arc. The wind caught the flat of the metal, creating a faint, low whistle. It was clumsy, and the sword still felt like a mismatched tool, but for the first time in her life, her spiritual veins didn't burn with frustration after a form.
From the shadow of a high bamboo stalk, a figure shifted. Yanxuan spun, her blade raised, only to find Wei Wuxian dangling upside down from a thick stalk, a half-eaten loquat in his hand.
"You're changing the rhythm," he said, dropping lightly to the forest floor without making a sound. His bright eyes scanned her stance, noting the loose grip and the relaxed shoulders.
Yanxuan tensed, expecting the usual teasing, or worse, a lecture on sect loyalty. But Wei Wuxian merely smiled—a knowing, quiet expression of satisfaction. He reached out, gently tapping the flat of her sword with his fingernail. A clear ting vibrated through the metal.
"I told you," he whispered, looking at her with the fierce protection of a brother who saw her hidden bruises. "Your spirit wants to sing. Let it. Don't let Jiang Cheng or Madam Yu tell you the only way to fight is to scream."
Before she could answer, he vanished back into the dark, leaving her alone with the rustling leaves.
The theoretical isolation of her practice could only last so short a time. Eventually, the fragile peace of the mountain was shattered. With Teacher Lan was away at Qinghe to attend the Discussion Conference, the classes were suspended for the most part, with everyone doing their own training. That day, while on the way to the Library Pavillion, Yanxuan ran into her brothers and the Twin Jades talking about a night hunt at Caiyi Town. Wanting to know what was going on, Yanxuan joins them just in time to hear Wei Wuxian talk Lan Xichen into letting them to join the hunt.
"Very well, if it is as you say Wei-Gonzi, Jiang-Gonzi, then please, join us," Xichen said, offering a formal bow of invitation.
Jiang Cheng’s eyes lit up with fierce pride. This was the chance he had been waiting for—a live battlefield to prove that the Jiang Sect's raw power was superior to the passive, meditative arts of Gusu. "Yunmeng Jiang accepts the invitation, Zewu-Jun. We will try not to dissappoint."
As they waited for the lan disciples at the gates, Yanxuan stood to the side, her heart thumping against her ribs. This wasn't a quiet bamboo grove anymore. This was a live, unpredictable threat, and she was going into it with a broken style and a weapon that didn't fit her hands.
The journey down the mountain path was tense. By the time they reached the canal docks of Caiyi Town, the normal cheerful bustle of the water market was entirely gone. The wooden skiffs of the loquat sellers were tied up securely, abandoned by their owners.
The water itself had changed. The vibrant, translucent green that usually characterized the Gusu rivers had turned an opaque, rotting black. A thick, unnatural mist hung low over the surface, smelling of stale mud and stagnant decay.
"This isn't a normal migration," Wei Wuxian murmured, leaning over the edge of the wooden pier as the Lan cultivators readied long, narrow skiffs. "The energy here is too heavy. It feels... concentrated."
"It's just water ghouls," Jiang Cheng scoffed, leaping lightly onto one of the boats, his hand resting firmly on the pommel of his sword. "They hide in the mud because they're afraid of the light. We'll drag them out."
Lan Xichen and Lan Wangji each took a lead boat, their white robes a sharp contrast against the murky, dark horizon. Yanxuan stepped onto another alongside Wei Wuxian, her boots immediately tracking the damp, slick moisture of the river liner.
As they pushed off from the docks, the silence of the river became deafening. The only sound was the synchronized splash of the oars and the low, uneasy creaking of the wooden hulls.
Three miles into the delta, the river died. The current stopped moving entirely.
"Lan Zhan!" Wei Wuxian shouted from the bow, his voice cutting through the fog like a knife. In a seemingly mischievous bid to get Lan Wangji's attention, Wei Wuxian kicked up a sudden spray of water. Reacting with characteristic grace, Lan Wangji leapt onto his brother’s skiff to escape the splash—only for Wei Wuxian to instantly tip the abandoned boat completely over.
Before Jiang Cheng could even yell a furious reprimand at his brother's antics, the overturned hull exposed the dark truth: a swarm of pale, water-logged ghouls were clinging frantically to the underside of the wood, using the boat as a shield. Seizing the opening, a nearby Lan disciple reacted instantly, casting a heavy suppression talisman that locked the creatures in place before they could scatter into the depths.
As the spray settled, Wei Wuxian offered a cheeky, unbothered grin to a startled Lan Xichen. "The draft of Lan Wangji’s boat was riding entirely too low in the water to be carrying only one person, Zewu-Jun," he explained, casually slinging his sword over his shoulder. "Water doesn't lie about weight."
With the hidden threat exposed, the absolute chaos of the river truly erupted. The water ghouls, realizing their camouflage was blown, abandoned all stealth. Hundreds of pale, rotting hands broke the surface at once, clawing at the hulls of the remaining skiffs. Jiang Cheng was a whirlwind of motion at the bow, his sword flashing with jagged purple light as he severed tendrils of hair and decayed flesh, treating the shifting river like a solid floor. Wei Wuxian's laughter cut through the mist as he flung talismans, the resulting explosions hissing angrily against the dark water.
Yanxuan, however, did not strike. She stood at the center of the rocking skiff, her eyes closed, her boots soaked in the spray. The physical world—the shouting of the cultivators, the splashing of the oars, the groaning of the wood—faded into a background hum. In her mind's eye, she saw the river as a massive, fluid web of pressure.
The water ghouls were knots within that web, their movements creating sharp, erratic distortions in the current. Physical steel could cut their flesh, but it could not dispel the malice that animated them; the water simply absorbed the impact, resetting itself instantly.
Match the current, the text from Lan Xichen had said. Do not fight the medium. Use it.
Yanxuan drew her blade. She did not drive it forward in a piercing thrust. Instead, she immersed the tip of her steel directly into the swirling water and began to rotate her wrist, tracing a series of precise, overlapping circles. She forced the spiritual energy from her core not into a sharp edge, but into a rhythmic, pulsing frequency that matched the natural swell of the river.
Huuuuum.
A low, deep vibration groaned from beneath the boat. The water around their skiff began to ripple in perfect, geometric concentric circles, expanding outward with terrifying speed. When these ripples collided with the oncoming water ghouls, the sonic resonance tore through the creatures' spiritual structures, shattering their illusion barriers and causing their dark forms to dissolve into harmless foam before they could even touch the wood.
Jiang Cheng whipped around, his jaw dropping as he stared at the suddenly clear perimeter around their boat. Wei Wuxian let out a sharp, appreciative whistle from the bow.
From his sword a few yards away, Lan Xichen paused, his hand loosely holding his xiao. He looked across the water at Yanxuan, a brilliant, genuine smile breaking across his features as he recognized the principles they had discussed in the back hills, beautifully executed through the medium of Yunmeng's element.
"Incredible," Xichen murmured.
Looking back at his smile, Yanxuan felt a profound shift settle deep within her golden core—a realization so absolute that her mind for the very first time, seemed to have found a place that she'd belong.
Upon their return to Lotus Pier weeks later, Sect Leader Jiang Fengmian would take a note of his daughter's evolving style. Recognizing that a standard Jiang sword was unsuited for her unique cultivation, he would take her to the ancestral smithies of Yunmeng. For three days and three nights, they would worked alongside the master craftsmen, melting down rare spiritual iron that had been seasoned by the wind of the gorges.
The resulting masterpiece - a sword named Qingyi—Clear Ripples. Along the spine of the slender, silver blade ran three intricate, narrow, hollowed-out grooves. When the sword was drawn normally, it looked like any other weapon; but when spiritual energy was funneled through the hilt, the wind rushing through those grooves transformed the blade into a tuning fork of devastating power, capable of releasing targeted acoustic shockwaves through air or water.
Stepping closer as the water grew still again, Lan Wangji kept his eyes fixed on the dark, elegant blade in his companion's hand. "What is the name of your sword?" he asked, his voice characteristically cool but carrying a rare undercurrent of genuine curiosity. The sound jolted her to the reality of the Biling Lake, dragged Yanxuan back to the present.
Wei Wuxian blinked, a brilliant, rogue smile spreading across his face. He tilted the scabbard toward the pristine Lan prodigy, pointing directly to the two elegant characters etched into the metal.
"Suibian," Wei Wuxian replied brightly.
Lan Wangji’s brows knit together in immediate, icy disapproval. "This weapon is a spiritual masterpiece," he chided, his voice dropping an octave. "To call it 'Whatever' is an insult to the steel, and an act of sheer frivolity."
"No, no, Lan Zhan, you misunderstand me!" Wei Wuxian laughed, thoroughly delighted by the reaction. "I’m not being frivolous. That is literally its name. Look for yourself—Suibian!"
Left entirely flabbergasted by the absolute absurdity of a high-grade spiritual sword being named Whatever, Lan Wangji could only stare in stunned, stone-faced silence, utterly speechless as Wei Wuxian chuckled and turned back to the dark river. Knowing what was coming Yanxuan let the by play wash over her, gazing out into the vast water body.
Beyond the boundary of Yanxuan’s resonance, the water was thickening further, changing from a murky olive to an ominous, ink-like black. The air grew heavy with a suffocating stench of rot, and the localized clearing she had made was suddenly swallowed by a massive, chaotic churning as an even greater, unyielding darkness swarmed the wider fleet.
From the lead boat, Lan Wangji moved with crisp, cold authority. He unsheathed Bichen, the pristine blue glare of his blade slicing through the mist as he cast it deep into the dark water. But when the sword flew back into his hand, its tip was clean. It had struck nothing.
Desperate to prove himself, or perhaps just to copy the formidable Second Young Master Lan, a disciple named Su She quickly echoed the movement. He thrust his own sword into the roiling current. For a second, nothing happened—and then the river swallowed it. Su She whistled and gestured frantically, trying to recall his weapon, but his sword didn't return. The water had taken it.
"We must leave. Immediately." Lan Wangji’s voice cut through the spray, sharp and urgent. His eyes swept the widening expanse of dark water. "Not an attack. Led us here. We are in the center of the lake."
Before the weight of his words could fully sink in, the current caught them, spinning their skiffs in a slow, terrifying circle.
"Mount your swords!" Lan Xichen commanded, his voice carrying a rare, ringing notes of absolute authority over the roar of the river. "Fly out!"
Around them, steel left scabbards. Jiang Cheng vaulted into the air, his purple robes snapping in the wind as his blade caught him. Yanxuan drew her own sword, preparing to channel her energy and follow, but a sudden shout from Wei Wuxian made her freeze.
"Hey!" he yelled.
Yanxuan looked back. Su She’s boat was dropping rapidly, the wood groaning as it was sucked into the center of what was quickly becoming a massive, churning vortex. Without his sword, the disciple was completely trapped, frozen in sheer terror as the black water lapped at his boots.
Before anyone could stop him, Wei Wuxian dove downward. He didn't hesitate. He reached out from his own sword, grabbing Su She by the back of his robes and attempting to haul him up into the air. But Suibian wasn't balanced for a double burden, especially not with the terrifying downward draft of the whirlpool pulling at them. The blade wavered, sinking lower and lower toward the foam.
“Wuxian!” The cry tore from Yanxuan's throat. She braced her weight to dive after them, but a streak of pure, blinding white light cut across her vision.
Lan Wangji descended like a falling star. With absolute precision, he caught Wei Wuxian firmly by the collar of his robes, his strength unyielding as Bichen held all three of them aloft, defying the crushing gravity of the vortex beneath.
As they pulled away from the swirling maw, the true scale of the disaster revealed itself below them. The lake was a giant, hollow eye of black water, devouring everything in its path.
"This isn't a colony of ghouls," Lan Xichen said, his face pale as he stared down at the terrifying phenomenon from his sword.
"A Waterborne Abyss," Lan Wangji finished, his grip tight on Wei Wuxian's collar, his voice grimmer than Yanxuan had ever heard it.
Yanxuan's heart hammered against her ribs as she hovered beside them. This wasn't just a localized haunting. A Waterborne Abyss was a living disaster—a malignant, consuming entity that meant the waters of Gusu were no longer safe, and the darkness they were fighting was shifting into something far worse than they had prepared for.