The eastern passage transformed with each mile they traveled. Water-smoothed walls gave way to increasingly crystalline formations—salt and mineral deposits creating delicate structures that caught the Imperial Jade Seal's light and fractured it into prismatic patterns across the tunnel.
"The air grows drier," Lin Fei noted on their second day underground. "And warmer. We must be approaching the desert periphery."
Liu Yun nodded, feeling the change himself. The Earth Shattering Sword had grown unusually warm against his back, resonating with the shifting elemental balance around them. Earth and water were gradually yielding to a new domain—one of sand and scorching heat.
"These formations shouldn't exist naturally," Jiang Tao observed, examining crystalline structures that resembled frozen waves. "They appear to be time-locked—moments of elemental transformation captured and preserved."
The Imperial Jade Seal hovered close to one particularly elaborate formation. "Temporal engineering confirmed. Sand Shaper technique signature detected."
Liu Yun reached out to touch the nearest crystal. It felt simultaneously hot and cold beneath his fingertips, as if experiencing multiple temperature states at once. "They've manipulated the very passage of time within these tunnels. Creating... transitional spaces."
"Acclimatization chambers," Lin Fei suggested. "Allowing visitors from other elemental domains to adapt gradually to desert conditions."
As they ventured deeper, the passage floor transformed from smooth stone to packed sand. The ceiling grew higher, opening into vast caverns where light filtered down through crystal skylights—natural formations that channeled the desert sun from far above.
"According to the ancient maps, we should reach the emergence point by nightfall," Jiang Tao said, consulting his records. "A sacred site called the 'First Dune'—where earth first gave way to sand in the creation myths of the Sand Shapers."
The final hours of their underground journey brought increasingly strange phenomena. Time itself seemed inconsistent—moments stretched or compressed unpredictably. Liu Yun would blink and find himself several steps further along the passage with no memory of taking them. Or he would watch a single grain of sand fall for what seemed like minutes before it finally reached the ground.
"The temporal distortions are intensifying," Lin Fei warned, her voice echoing strangely, as if reaching them from different moments simultaneously. "We need to prepare ourselves before we emerge."
The Imperial Jade Seal expanded to twice its normal size, pulsing with contained energy. "Protective chronofield activating. Limited temporal insulation possible for covenant representatives."
A subtle shimmering enveloped the three companions—not quite visible, but perceptible as a slight resistance in the air around them, like moving through water instead of atmosphere.
"It won't offer complete protection," Liu Yun realized, feeling the sword's influence supplementing the seal's power. "But it might prevent us from ending up like the messenger."
The passage finally opened into a perfectly circular chamber with walls of polished glass—or what appeared to be glass until closer inspection revealed it was actually sand, frozen mid-flow into translucent sheets. Seven archways ringed the chamber, though all but two were sealed by the same glass-like barrier.
"The Path of Convergence," Jiang Tao breathed in wonder. "I thought it was just a legend. Seven paths, one for each bloodline, all leading to the covenant's heart."
The Imperial Jade Seal drifted to the center of the chamber, where a raised dais bore familiar covenant markings. The chamber resonated with energy as the seal settled into place, and three of the seven archways began to glow—representing Earth Vein, Water Weaver, and directly ahead, Sand Shaper domains.
"Three paths opened, four remain sealed," the seal intoned. "Covenant progression continues as predicted."
A sudden vibration shook the chamber, sending ripples through the glass-sand walls as if they had momentarily liquefied before refreezing. The archway leading to the desert pulsed with amber light.
"We've been noticed," Lin Fei warned, drawing her weapon. "The Sand Shapers are aware of our presence."
The archway's barrier thinned, becoming translucent enough to reveal what lay beyond—a landscape of golden dunes stretching to the horizon under twin moons that shouldn't both be full simultaneously. Liu Yun realized with a start that one moon showed the night sky as it should be now, while the other displayed a different phase—perhaps a past or future alignment.
"Approach permitted," came a voice that seemed to originate from everywhere and nowhere at once. It resonated through multiple timelines, the same words repeated with subtle variations in tone and emphasis. "The Covenant Seekers may cross the temporal threshold."
The barrier dissolved completely, and scorching desert air rushed into the chamber, carrying with it the scent of sun-baked sand and something else—an electric tang that made Liu Yun's skin prickle with recognition of profound power.
"The Sand Shapers await," the voice continued. "To witness is to transform. To transform is to transcend. To transcend is to fulfill the covenant's design."
Liu Yun exchanged glances with his companions. The warning was clear—proceeding meant accepting transformation. The Water Weaver messenger had been unprepared for that change and paid the ultimate price. Would their covenant connections protect them, or merely ensure they remained conscious through whatever metamorphosis awaited?
"We came seeking the fourth bloodline," Liu Yun said resolutely. "We accept the terms of approach."
The Imperial Jade Seal rose from the dais and returned to hover above them. "Covenant parameters acknowledged. Partial protection protocols activated. Transformation quotient: uncertain."
Lin Fei squared her shoulders. "Every bloodline demands its price. We've come too far to hesitate now."
Together, they stepped through the archway onto the sands of the Northern Desert. The barrier rematerialized behind them, sealing the passage. Ahead, the dunes shifted in patterns that defied natural wind currents—moving with purpose, responding to unseen will.
In the distance, a massive structure shimmered—visible one moment, transparent the next—a citadel built from crystallized time and solidified sand. And approaching them across the dunes came figures that seemed to exist in multiple states simultaneously, leaving trails of afterimages with each step.
The Sand Shapers had arrived to welcome the Covenant Seekers to their temporal domain.