As they gradually approached, the rustling sound became clearer. When they turned a corner, the scene before them made them stunned. A swarm of bats, shrouded in darkness, hung upside down from the cave roof. At this moment, being startled by their movements, they frantically flapped their wings and flew up. Shen Jingqi was so frightened that he almost cried out, randomly swinging the sword in his hand. Li Baiyu quickly grabbed his arm and shouted loudly, "Don't move! They won't actively attack humans!"

Calmed by his senior sister, Shen Jingqi gradually settled down. After the bats circled above their heads for a while, they gradually flew towards the depths of the cave. Shen Jingqi let out a long breath, wiped the cold sweat from his forehead, and said with a bitter smile, "Senior sister, that was really dangerous just now." Li Baiyu patted his shoulder, smiled and said, "It's okay. It's normal to be defensive the first time you encounter such a situation. But we can't panic like this in the future; we still have to move on."

They continued along the cave, and the surrounding air became increasingly humid. Strange symbols and patterns began to appear on the walls. Shen Jingqi leaned in curiously to observe. The lines of those symbols twisted as if harboring some mysterious power. "Senior sister, look at these symbols. Could they be some kind of ancient writing? Could they be related to the secret of the castle?" Shen Jingqi said excitedly.

Li Baiyu carefully examined the symbols. After pondering for a moment, she said, "It's possible. These symbols seem very ancient and might indeed hide important clues. Let's record them; they might come in handy later." Saying so, she took out paper and pen from her backpack and began carefully copying those symbols.

Just as they were focused on recording the symbols, a deep roar echoed from the depths of the cave, causing the cave to tremble slightly.

"Senior sister, what is... what is that sound?!" Li Baiyu's expression became very serious. She gripped the dagger in her hand tightly and said with determined eyes, "No matter what it is, we can't back down. Jingqi, stay close to me, let's go take a look together."

They cautiously proceeded in the direction of the sound, feeling as if they were walking on the edge of a cliff with every step. As they got closer, the roar became clearer, as if a giant beast was waiting for them ahead. Finally, they arrived at a spacious cave hall. The sight before them made them gasp.

In the center of the hall lay a huge, shaggy monster. Its eyes glinted with fierce red light, and its mouth slightly opened, revealing sharp fangs with saliva constantly dripping from its mouth corners. The monster seemed to sense their arrival, slowly raised its head, and let out an earth-shaking roar. The sound echoed in the cave, hurting their ears.

Li Baiyu was the first to approach the monster, her steps firm and steady, with an unflinching courage in her eyes. Shen Jingqi followed behind her. The monster watched as they gradually got closer and let out an angry roar, suddenly standing up, its massive body pressing toward them like a small mountain.

Li Baiyu nimbly dodged, avoiding the monster's first attack, while quickly stabbing at the monster with her dagger. The monster howled in pain, turning to pounce on Li Baiyu. Seeing this, Shen Jingqi shouted, "Senior sister, watch out!" He wielded his long sword, rushing towards the monster from the side, attempting to divert its attention.

The monster, enraged by Shen Jingqi's attack, temporarily gave up its pursuit of Li Baiyu and turned to lunge at him. Shen Jingqi was shocked, but it was too late to evade. He could only instinctively raise his long sword to block. The monster's claws struck the long sword hard, the force so great that Shen Jingqi's arm numbed, nearly dropping the sword from his hand.

As Shen Jingqi was in a predicament, Li Baiyu launched an attack from behind the monster, timing it perfectly to stab her dagger into the monster's hind leg. The monster let out another painful howl, its body swaying. Shen Jingqi seized the opportunity to stabilize himself and swung his long sword at the monster again. The monster, sensing danger, ignored its pain and suddenly turned to flee deeper into the cave.

Watching the retreating figure of the monster, Shen Jingqi was panting heavily. Li Baiyu walked beside him, smiling and saying, "The appearance of this monster is strange; it seems to be guarding something."

Shen Jingqi nodded, saying, "Senior sister is right. This monster is so fierce, it wouldn't be guarding this place for no reason. Maybe there's something more important hidden in the depths of the cave." Li Baiyu stood up, brushed off the dust from her body, and said, "Exactly. Let's rest for a moment, then continue forward and see what secret this monster is guarding."

They rested in place for a while, replenishing some energy, and then continued heading deeper into the cave. As they kept advancing, the surrounding temperature became increasingly cold, with a bone-piercing chill permeating the air. Shen Jingqi couldn't help but shiver, wrapping his coat tightly, and asked, "Senior sister, why is this place so cold? It feels increasingly unsettling."

Li Baiyu frowned and said, "I don't know either. But the stranger it is, the more it shows this place is not simple. Let's be careful; we might soon find the answer." They continued forward, and suddenly, a gigantic stone door appeared ahead. The stone door was covered with intricate runes and patterns, exuding a mysterious aura.

Shen Jingqi excitedly ran forward to observe the runes on the stone door carefully. "Senior sister, look at these runes. They seem somewhat similar to what we saw on the walls earlier. Maybe opening this stone door will reveal the castle's secret." Li Baiyu approached, examining the stone door attentively, and said, "It's possible. But this stone door looks very heavy, and with such complex runes on it, how do we open it?"

Just as they were contemplating how to open the stone door, the runes on the door suddenly began to glow, the light growing brighter. Shen Jingqi and Li Baiyu instinctively took a few steps back, watching the stone door warily. As the runes flashed faster, the stone door slowly opened, releasing a powerful air current that nearly knocked them over.

After the air current slightly subsided, they cautiously stepped through the stone door. Behind the door was a massive circular chamber, with a colossal stone coffin placed at its center. The stone coffin was engraved with exquisite patterns, surrounded by four huge stone pillars, burning with eerie blue flames.

Shen Jingqi and Li Baiyu exchanged a look, seeing surprise and vigilance in each other's eyes. They slowly approached the stone coffin, filled with doubt and curiosity. What could possibly be hidden inside this stone coffin? The master of the castle, or an even more terrifying monster?

Just a few steps away from the stone coffin, suddenly, the lid of the coffin slowly opened, releasing an intense aura that hit them. Shen Jingqi and Li Baiyu quickly covered their noses, nervously watching the stone coffin. From within the stone coffin, a figure slowly rose: a man dressed in luxurious robes, his face pale as paper, with eyes gleaming with eerie red light.