When Zhang Heng opened his eyes again, he regained his vision, and it was clearer than before the red tide appeared. This was the first time he used his Filter Lens underwater. Initially, he was worried that the red tide did not fall under the natural category, but now, it seemed that the lens worked well in this red tide.

  The red tide disappeared before him, and the seawater became transparent to him within 300 meters.

  Zhang Heng soon found Nellie, who had separated from him earlier. The latter now swam toward the ruins. And in front of her, Zhang Heng’s old friend, a half-man, half-fish-frog monster, was holding a flashlight, flashing at Nellie to draw her closer to him.

  Zhang Heng did not spot other monsters beside him for the time being.

  The other good news was that after a short observation, Zhang Heng noticed the red tide did affect the monster. However, its visibility in the red tide was still higher than that of humans, and he could probably see three to four meters in front of him.

  This was also why he could see Nellie, but Nellie couldn’t see the monster.

  However, Zhang Heng still could not see Han Lu nearby.

  After Zhang Heng took a good look at the place, he saw there was no other place for Han Lu to hide. He also knew that Han Lu’s disappearance must be related to the monster. If he followed this monster, he might be able to find Han Lu.

  Zhang Heng did not hesitate anymore, swimming toward Nellie the moment he put on his mask. At the same time, he paid attention to the distance between himself and the monster in front of him, keeping himself out of its field of vision.

  Zhang Heng saw that Nellie, led by the monster, had come to the stone wall where Han Lu was standing earlier. Just when Zhang Heng thought that they had no way to go, the stone wall began to tremble. The one-foot-wide crack that could only fit a turtle began to expand, just like a giant beast opening its mouth. The half-man, half-fish-frog monster who led the way entered the crack. After that, he took out a flashlight to continue to draw Nellie closer to him. No matter how dumb Nellie was, she felt that something wasn’t right once the crack widened in front of her.

  She hesitated for a moment outside the crack, but her desire of finding Han Lu overpowered her fear. Hence, Nellie gritted her teeth and swam to the crack. However, the light disappeared soon after she entered.

  Nellie’s mind began to sober up after being affected by the red seawater for quite some time. It was then that fear started to kick in. The diving guides were not life-saving talismans for the divers. It was true that they were responsible for helping the divers to deal with some threats, but they couldn’t deal with all of them.

  When these threats were too dangerous for them to handle or that they knew they might lose their lives over it, the guides needed to know that it was time to let go. This was just a job, after all, and a specific price had to be paid if they wanted to play the hero. The current situation was obviously beyond what Nellie could handle. She was in an unfamiliar tunnel, surrounded by strange rocks, and the visibility was very low.

  Nellie did not know how long this tunnel was, whether there was a fork in the path, or where it would take her. After she swam for a short distance, her diving computer reminded her that she was going deeper into the ocean. And that was not a good sign. Suddenly, Nellie remembered she left Zhang Heng outside.

  This was also one of the main reasons why she decided to turn around.

  But when she returned using the same way she entered the crack, she discovered something that frightened her. The crack on the wall was now closed again, returning to a width of about only one foot. Nelly could no longer stay calm this time. She tried to squeeze her hands into the gap to attempt to widen the crack. Since it did expand earlier, it meant that walls were probably movable.

  The reality, however, was always harsh.

  No matter how hard she tried, the crack remained unmoved, as if it had never expanded before. Nellie consumed a lot of oxygen as she used all of her strength in an attempt to free herself. The fruitless attempts left her with frustration. But fortunately, she was an experienced diver, and she had dealt with underwater crises before. Even in such a harsh environment, she did not collapse like one of those rookies.

  After realizing that the crack in front of her would not open again, Nellie calmed herself down, checked her residual pressure gauge, confirming her direction with her dive computer, and continued to swim along the underwater tunnel.

  Now, she could only hope that there were other exits ahead of her. Nellie turned on the flashlight, illuminating the paths ahead to look for an exit. At the same time, she hoped her flashlight could get in touch with “Han Lu” again.

  Instead of seeing Han Lu, though, she saw something else. The underwater ruins on Yonaguni Island caused a great sensation when they were first discovered. Since there was still no critical evidence to prove that the ruins were left behind a lost civilization, they thought that the neatly built brick walls and steps were just something that nature had formed.

  In order to prove that the ruins were actual, some enthusiasts even forged ancient coins and pottery, decorated with fancy patterns that they designed. These fake relics, however, wouldn’t be able to pass modern scientific tests. Nellie now knew that what she was seeing couldn’t possibly have been forged by modern people.

  The carvings on both sides of the stone wall were old. Simple to understand and concise, it told the story of mermaid-like creatures hunting sea beasts. Other than that, some of the pictures told of love stories between humans. At least, that was how Nellie deciphered it.

  The mermaid gifted something to the woman on the shore. After the two married, the woman gave birth to a couple of kids, who returned to the sea after they grew up. Nellie had heard of a few mermaid legends, and she thought them to be quite romantic.

  The carvings on the wall mesmerized a stunned Nellie. Even though the carvings had been baptized by time and current, they still looked incredibly real. If she were not in danger, Nellie would definitely want to stop and enjoy it.

  In fact, she had already taken out her underwater camera to snap a couple of pictures of the carvings. These carvings were tantamount to ending the ancient ruins’ debate on Yonaguni Island, whether it was the magical craftsmanship of nature or something made during early civilizations. Any of those pictures could cause a huge uproar on the shore.

  Before she could do that, however, she had to think of a way to keep herself alive.