Chapter 71: The Sand-Skeleton King of the Underground River

The sound of the undercurrents in the subterranean river echoed like a weeping dirge. Lu Chen’s military boots stepped upon the slippery pebbles, sending up splashes that caught the flashlight beam, refracting into fine, glittering gold dust—that was the energy of the Three-Oath Totem seeping through his palms, sending ripples across the water.

"Three hundred meters to the main channel." Su Qing’s tablet flickered intermittently, a layer of condensation clinging to its waterproof casing. "The detector shows a strong energy response ahead, more than ten times stronger than the signal of the caravan puppets."

Alicia’s silver-bird necklace was wrapped around her wrist, its blue light waxing and waning with the flow of the current. She had just used the Requiem to pacify a school of sand scorpions blocking the tunnel. The fractured end of her bone flute was still oozing blood, mixing with the metallic tang of the river water in a strangely intoxicating, sweet-sickening scent: "It is the Sand Skeletal King. Ancient texts say that a guardian beast is hidden within the subterranean river of the ancient Silk Road, formed from the fused remains of lost travelers to guard the caravan's treasure."

"Treasure?" Chen Yu dragged his heavy machine gun through the water, leaving a white wake. The anti-entropy runes on the barrel were tarnished dark by the dampness. "More like a pet raised by Williams. That last wave of sand scorpions was clearly clearing the field for it."

The bones of the Tang dynasty soldiers formed a wedge formation to lead the way, the crisp, harsh sound of their rusted swords parting the water ringing out. The cavalry skeletons in the very front suddenly halted, their horse bones uneasily pawning the riverbed, the golden light in their eye sockets flickering violently—from the darkness ahead came a heavy breathing sound, as though a giant whale were lurking at the bottom of the river.

Lu Chen suddenly raised his hand to signal silence, and their flashlight beams simultaneously cut forward.

The surface of the main channel rippled with an eerie phosphorescence. In the center of the hundred-meter-wide river, a massive shadow was slowly shifting. Its silhouette undulated with the waves, at times transforming into a winding giant serpent, at other times expanding into a disc covering the water's surface. Its outermost scales reflected a metallic sheen; upon closer inspection, they were actually pieced together from countless ancient coins and broken spear points and swords.

"That's... the Sand Skeletal King?" Wang Lu’s medical pack almost slipped from her grasp as she pointed to the bone spurs protruding from the top of the shadow. Those spurs were wrapped in rotting silk, fluttering in the current like spirit-recruiting banners. "It... it seems to be sleeping?"

Before her voice faded, the water surface suddenly exploded!

Not with ordinary splashes, but with a ten-meter-wide water tornado shooting straight into the sky, carrying countless copper coins and iron debris. In the center of the water tornado, the true form of the Sand Skeletal King was finally revealed—a hundred-meter-long behemoth whose torso resembled a sand python magnified a hundred times, covered in scales cast from coins and weapons; its head was a giant visage piled high with countless skulls, burning with ghostly blue flames in their eye sockets. Most terrifying of all was its mouthparts, the upper and lower jaws lined with razor-sharp blades that, when opened, spewed a stream of dark green venom that instantly dissolved a massive hole upon hitting the rock wall.

"Defend!" Lu Chen’s bone saber cleared its scabbard in an instant, the golden light of the Three-Oath Totem spreading across the water's surface to form a golden barrier. "It's awake!"

The giant face of the Sand Skeletal King turned toward them, the piled skulls emitting a clicking friction sound as if inspecting the intruders. When its gaze swept across the Tang dynasty skeleton soldiers, the ghostly blue flames flared violently, clearly mistaking these ancient undead for its own kind.

"No!" Alicia suddenly raised her bone flute. "Its core is glowing!"

Following the direction of her finger, everyone saw a faint blue light leaking through the gaps in the scales on the Sand Skeletal King’s chest. The light shared a similar frequency with the energy field of the First Altar, yet it was purer, resembling an encapsulated sapphire.

"It's the caravan leader's skull!" Su Qing’s tablet suddenly captured a clear energy signal, its three-dimensional model displaying a complete skull embedded right where the Sand Skeletal King’s heart should be, with a jade pendant set in its eye socket, emitting a steady blue light. "That pendant... it's of the same origin as Lu Chen's Three-Oath Totem!"

Lu Chen’s pupils contracted sharply.

The jade pendant was shaped like a half-moon, perfectly complementing the pendant he had worn since childhood left by his father to form a complete circle. Could it be that what this Sand Skeletal King guarded was something connected to the Sand Keepers?

"Roar—!"

The Sand Skeletal King suddenly let out a deafening roar, its massive tail violently lashing the water and sending a towering wave crashing toward them. The Tang dynasty skeletons formed a human wall, their rusted swords crossing to form a net, yet they were beaten back step by step by the impact, many skeletons shattering under the force.

"It treats us as intruders!" Chen Yu's heavy machine gun fired in a wild barrage, the bullets striking the scales only to bounce harmlessly off the copper coins. "The defense on this thing is absurd!"

Even more terrifying was the venom. The Sand Skeletal King's mouthparts continuously sprayed dark green liquid columns that landed on the water, stirring up wisps of white smoke. Every pebble touched by the venom rapidly sanded down, transforming into writhing sand-crystal tentacles that crept toward Lu Chen and the others.

"Alicia! Play the Requiem!" Lu Chen’s bone saber cleaved a stream of venom. The moment the golden light collided with the venom, he saw the blue light on the Sand Skeletal King’s chest flicker slightly. "Its core is responding!"

Alicia immediately raised the bone flute to her lips, the clear, ethereal melody of the Requiem echoing through the river channel. Unlike before, this time she purposely accentuated the notes sharing the same origin as the jade pendant—the tune her father had taught her, one understood only by the descendants of the Sand Keepers.

A miracle occurred.

The Sand Skeletal King’s attacks suddenly slowed.

The spraying venom solidified in mid-air, its giant tail halted aloft, and the piled skulls ceased their threatening frictional sounds. As the melody of the Requiem reached its chest, that touch of blue light abruptly expanded, bleeding out through the gaps in its scales to form half a musical score of the *Yangguan Three Stacks* across the water's surface.

"It's communicating with us!" Su Qing’s tablet frantically recorded the energy signals. "These blue lights are its memory fragments! It's saying... it's waiting for someone who can break the seal of the jade pendant!"

Lu Chen suddenly understood.

The Sand Skeletal King was not a guardian beast, but a sealed guardian. The leader of the ancient Silk Road caravan was likely also a descendant of the Sand Keepers, using his own skull and jade pendant as the core to fuse with the remains of lost travelers, forming this giant beast for the purpose of guarding the secrets deep within the subterranean river—secrets that required the Three-Oath Totem to unlock.

"What Williams wants isn't the Sand Skeletal King, but what it guards!" Lu Chen’s bone saber pointed toward the darkness behind the Sand Skeletal King, where the water surface was preternaturally calm, as though an invisible barrier lay across it. "It's waiting for redemption!"

The giant face of the Sand Skeletal King suddenly lowered, the piled skulls parting to clear a path and exposing the glowing skull upon its chest. The jade pendant beat violently within the blue light, producing a powerful resonance with the Three-Oath Totem in Lu Chen’s palm, causing even the air to tremble.

"Now!" Alicia’s Requiem abruptly soared in pitch, the blue light of her silver-bird necklace intertwining with the Sand Skeletal King’s blue light to blast a breach in the scales upon its chest. "Attack the core!"

Lu Chen suddenly grabbed a rusted arrow from a Tang dynasty skeleton, pouring the entire golden radiance of the Three-Oath Totem into it. The energy of the Hope Totem flowed along the shaft, condensing at the arrowhead into a pulsing sphere of light—a power forged from the soldiers' desire for protection, the civilians' gratitude, and all unexpressed yearnings, possessing far greater penetrative force than mere anti-entropy energy.

"In the name of the Sand Keeper—" Lu Chen drew the bowstring to its limit, the veins on his arm bulging with exertion. "Be released!"

The arrow burning with the Hope Totem streaked like a golden lightning bolt, piercing through the path cleared by the Sand Skeletal King and striking precisely at the skull core on its chest.

*Squelch—*

The instant the arrowhead sank into the jade pendant, the Sand Skeletal King let out a roar that shook the river channel. Not of pain, but a long cry of release. The blue light on its chest erupted completely, engulfing the entire behemoth. The coin-and-weapon scales began to peel away, revealing the pristine white bones beneath.

Countless phantom images of travelers emerged from the skeletal frame. They wore diverse attire—merchants from the Western Regions, bodyguards from the Central Plains, envoys from Persia—all bowing deeply toward Lu Chen before dissolving into golden spots of light.

The torso of the Sand Skeletal King rapidly shrank within the blue light, the hundred-meter-long behemoth gradually reverting to a complete humanoid skeleton—an elderly man dressed in the attire of a Tang dynasty Sand Keeper. The skull on his chest was his own, with the jade pendant embedded right between his brows, emitting a gentle, warm glow.

"Thank you... descendant..." The elder's phantom bowed to Lu Chen with cupped hands, his voice old and comforted. "The subterranean river... conceals the other half... of the Sand Source's seal..."

Before his voice finished fading, the elder's phantom, along with his skeleton, turned into blue light that merged into the jade pendant between his brows. The pendant soared into the air, flying automatically toward Lu Chen to merge with the Three-Oath Totem in his palm.

The golden totem suddenly became whole, the previously missing crescent-shaped notch now filled, radiating an unprecedented brilliance. Lu Chen could feel a warm current flowing through his arm and throughout his body, as the barrier deep within the subterranean river slowly parted to reveal what lay beyond—a sunken altar, larger than the first and second ones combined, with the upper half of a fractured Requiem bone flute stabbed into the stone platform at its center, which would precisely fit the piece in Alicia's hand to form a complete flute.

"It's the third altar!" Alicia's voice carried a tremor of excitement. "Mother said a complete Requiem bone flute can completely suppress the Sand Source!"

Just as Chen Yu was about to speak, he pointed to the shadows at the edge of the altar. "What is that?"

From the shadows, a familiar figure slowly emerged, six pairs of sand-crystal wings glinting coldly in the blue light. It was none other than Williams, who should have been back in the fortress. In his grip was an unconscious child, around whose neck hung a silver locket identical to scout captain Batu's—it was An'an!

"I never would have imagined." Williams's mechanical arm choked An'an's throat, dark purple karmic fire dancing at his fingertips. "You actually managed to awaken the Sand Skeletal King. But no matter; the seal it guarded now belongs to me."

Lu Chen’s pupils contracted sharply, the golden light of the Three-Oath Totem turning instantly frigid. "Let her go!"

"Let her go?" Williams’s wild laughter echoed through the subterranean river. He abruptly hurled An'an toward the stone platform in the center of the altar, where sand-crystal tentacles instantly burst from the stone seams to tightly bind the child. "Using her blood as a sacrifice will正好 unlock the other half of the Sand Source's seal. Tell me, if Batu knew his daughter became fuel for the Sand Source, would he crawl out of the earth to settle accounts with you?"

An'an's cries were heart-wrenching, her silver locket clashing against the tentacles with desperate, brittle rings. Lu Chen moved to rush forward, but Alicia yanked him back.

"Don't be impulsive!" She pointed to the runes surrounding the altar, which were glowing black-purple within Williams’s karmic fire. "He's activating the sacrificial array! The moment we get close, An'an will be instantly sanded!"

Williams’s bone core suddenly split open, the red light of the blood of the same origin resonating with the altar's runes. The half bone flute on the stone platform began to vibrate, generating a repulsive reaction against the broken flute in Alicia's hand and producing a piercing shriek.

"See that?" Williams’s sand-crystal wings fully unfolded. "The Sand Source is calling for its other half of power! Once I break all the seals, you will all have to kneel before me!"

Lu Chen looked at the weeping An'an on the stone platform, then at the trembling broken flute in Alicia's hand, and suddenly understood the Sand Skeletal King's final words.

The seal of the Sand Source had been divided in two.

The third altar did not conceal hope, but a truth far more terrifying than the bone core—the other half of the Sand Source's power required the simultaneous sacrifice of the bloodlines of the Sand Keepers and the sand scorpions to be undone.

And Williams capturing An'an was not merely for leverage, but because the child carried the blood of Tribe X, making her the ultimate sacrifice.

The runes in the center of the altar suddenly flared, An'an's silver locket beginning to melt within the tentacles as tiny sand-crystal thorns surfaced across her skin.

The Three-Oath Totem of Lu Chen erupted with unprecedented golden light. He looked at Williams's smug face, and suddenly made a crazy decision.

He pulled Alicia tightly behind him, his bone saber pointing toward the altar. "Chen Yu, cover me! Su Qing, record the rune patterns! Wang Lu, get the purification potion ready!"

"What are you doing?!" Alicia's voice carried terror.

A resolute smile flashed at the corner of Lu Chen's mouth, while within the golden light of the totem on his palm, An'an's smiling face and Batu's back as he self-detonated faintly emerged:

"Batu traded his life for our chance; I cannot let his daughter die in vain."

He suddenly charged toward the altar, the golden light of the Three-Oath Totem trailing long afterimages behind him as he crashed directly toward the sand-crystal tentacles. Williams’s karmic fire immediately shot toward him, only to be forcefully cleaved apart by his bone saber.

"Courting death!" Williams’s giant pincers lunged for Lu Chen’s back. "Then let you pave the way for the Sand Source first!"

At that moment, Alicia suddenly raised her bone flute, playing a melody never heard before.

The melody was no longer the ethereal Requiem, but carried a tragic, epic power, like thousands of horses galloping across the desert. The broken flute in her hand and the half flute on the stone platform produced a new resonance—no longer repulsion, but... summons!

The half bone flute on the stone platform suddenly broke free from the sand-crystal tentacles, flying toward Alicia's broken flute.

The instant the two halves of the bone flute were about to merge, Williams's karmic fire arrived at Lu Chen's back.

Lu Chen did not turn back, simply pouring all the golden light of the Three-Oath Totem into the tentacles binding An'an—he would use the Sand Keeper's bloodline to temporarily suppress the activity of the sand crystals.

Yet he knew this was far from enough.

The true killer move lay with Alicia.

The moment the two halves of the bone flute merged, the complete Requiem bone flute erupted in blinding white light, colliding at the center of the altar with Lu Chen's golden light and Williams's karmic fire.

An'an's cries suddenly ceased.

Everyone froze.

On the stone platform, An'an's silver locket suddenly cracked, dropping a grain of golden sand the size of a rice kernel—the energy of the Sand Speaker's avatar that had merged into the silver locket before they dissipated.

Upon touching the white light of the Requiem bone flute, the golden sand suddenly burst into a warm orange-yellow, like the color of setting sun casting across the desert.

The seal of the Sand Source, at this very moment, manifested a third possibility.

It was neither undone by Williams, nor reinforced by Lu Chen, but...

Through the intertwining powers of the Sand Keeper, the descendant of the sand scorpions, and the avatar of the Sand Voice, an unknown mutation had occurred.

The runes in the center of the altar began to distort, black-purple and golden-white weaving together into a chaotic vortex. An'an's body slowly levitated within the vortex, the sand-crystal thorns on her skin receding to be replaced by a faint orange-yellow hue.

Williams's pupils constricted to needlepoints. "No... impossible! How could the Sand Source..."

Lu Chen and Alicia reached out simultaneously to grasp An'an, only to be repelled by the vortex's force. They watched as the child closed her eyes within the chaos, a pure smile playing at the corners of her lips, as though dreaming a sweet dream.

From the center of the vortex, a childish voice suddenly rang out, clear as if whispered directly into their ear:

"Father said, the sand remembers everything..."

This voice simultaneously carried An'an's innocence, the Sand Speaker's antiquity, and Isabella's gentleness.

Lu Chen's heart skipped a beat.

He suddenly understood the ultimate secret of the Sand Source.

This was never an evil force requiring a seal, but rather...

The memory of the Great Desert itself.

And An'an had become the first... medium capable of understanding the language of the sand.

The chaotic light of the vortex abruptly surged, submerging the entire subterranean river. Before losing consciousness, the last images Lu Chen saw were Williams's sand-crystal wings shattering to pieces in the light, and An'an's newly opened eyes—eyes reflecting the entire past and future of the Great Desert.

The true crisis was not that the Sand Source had been unsealed, but that it had awakened... in this manner.

And what they were about to face was the true master of the Great Desert, who knew all things.