One afternoon, Lin Yue was lost in thought, staring at a brocade handkerchief, her fingertips unconsciously tracing the faded gold thread at the edges. Ah Fu rushed in, clutching a stack of account books. The wind from his footsteps rippled the handkerchief, and she suddenly discovered the faint traces of fine lines peeking through the fabric. Carefully plucking the threads with a silver needle, she revealed a fragment of a star map, identical to the symbols on the map in the darkroom.

"Young Master Xia!" Lin Yue rushed into the study, clutching a handkerchief, only to find Xia Zichen staring gravely at a secret letter on his desk. "Urgent report from the border: Merchants have discovered a mysterious altar in the Western Desert, matching the markings left by the organization." He looked up at the handkerchief in Lin Yue's hand, his eyes trembling slightly. "Perhaps this is the clue that will lead us to the other half of the star map."

Three days later, a cavalry team set out on a journey westward. Under the scorching desert sun, Lin Yue's temples throbbed, and he felt as if he were transported back to the late nights of modern times, working on a paper. That was until Ah Fu pointed at a faint silhouette looming in the distant sandstorm and exclaimed, "That's it!" A stone formation covered in mysterious totems emerged from the dust and mist, perfectly aligning with the Jinpa star map.

Before anyone could approach, the stone formation suddenly lit up with a faint blue light. A dozen masked men emerged from behind the sand dunes, their leader sneering, "Think you can rest easy just by destroying the organization? The real game has only just begun." A gleaming scimitar slashed down. As Lin Yue dodged, her handkerchief unexpectedly drifted toward the center of the stone formation. In an instant, the world turned upside down. She saw countless stars spinning beneath her feet, and the exclamations of Xia Zichen and Ah Fu seemed to echo from afar.

When the light faded, Lin Yue found herself in a magnificent underground palace. Murals on the walls revealed a secret from thousands of years ago: an immortal once used the power of a star map to protect the peace of the nations, but his power was too great and he was sealed away. The brocade handkerchief was one of the keys to unlock this seal.

"So we've always been guarding a power that shouldn't be awakened." A familiar voice came from behind. Lin Yue turned around and saw Xia Zichen and Ah Fu standing at the entrance, covered in blood. "But this time, we choose to face it with you."

Outside the underground palace, the remnants of a mysterious organization were gathering their forces; deep within the crypt, a sealed power began to stir, guided by a brocade handkerchief. Lin Yue clasped her companions' hands, knowing that the true test had just begun. This time, they not only had to protect the Tang Dynasty but also decide the fate of an ancient power.

Lin Yue dug her nails deep into her palms, listening to the hum of gears turning from deep within the underground palace. Xia Zichen suddenly tugged her back three steps. A bronze crossbow bolt grazed her hair and pierced the ground. The spiderweb-like silver threads wrapped around the tail of the arrow glowed eerily in the darkness.

"It's heart-eating spider silk!" Ah Fu's voice trembled. He hurriedly opened his shirt and tore off a strip of cloth to wrap around the wound. His forearm, which had been scratched by the crossbow arrow while protecting Lin Yue, was already turning blue and black. Xia Zichen's longsword flashed a half circle of silver light, precisely severing the dangling spider silk. The silver threads that touched the ground began to corrode the hard bluestone.

Suddenly, the immortal totem on the mural oozed a dark red liquid, gathering into a winding line of blood that crawled up Lin Yue's ankle. She stumbled and held onto the wall. The moment her fingertips touched the mural, countless fragments of memories flooded into her mind - at the final moment of the sealing ceremony a thousand years ago, the immortal split the power of the star map into three parts. Two of them turned into brocade handkerchiefs and circulated in the human world, while the third...

"Be careful!" Xia Zichen's roar stung his eardrums. Lin Yue instinctively rolled to the side. A three-foot-diameter pit suddenly appeared where he had been standing. Dozens of scaly tentacles jutted out from the bottom. The dome of the underground palace began to peel away, revealing a massive bronze armillary sphere hovering above, each needle pointing towards the handkerchief in Lin Yue's hand.

Ah Fu suddenly ripped open the wine bag at his waist and doused it at the tentacles. The moment flames erupted, he was sent flying by an invisible force. As Xia Zichen swung his sword to sever the tentacles, Lin Yue saw a star pattern similar to the one in the mural appear on the back of his neck, glowing with the movement of the armillary sphere.

"So you are..." Lin Yue's question was interrupted by a violent shaking. From deep within the underground palace came the resounding sound of snapping chains, and a chilling air with the smell of rust washed over her. When the hands of the armillary sphere completely aligned, the silk handkerchief in her hand suddenly transformed into stardust, blending into the star pattern on Xia Zichen's neck. The boy's pupils turned a deep black, and his voice seemed to come from ancient times: "After a thousand years, I've finally waited for this key."