The oil bottle told Zhang Haike that the entire area beneath this strange place is the ruins of the ancient city of Sizhou, with at least four layers buried beneath their feet; they are only on the first layer. The Zhang family has been operating this ancient city for thirty years. After a flood during the Kangxi period, the ancient city was buried and disappeared under silt, and most of the treasures were never recovered, so there are many valuable items hidden in the mud.

The ancient city of Sizhou was established during the Sui Dynasty, around fifteen hundred years ago. This era saw continuous floods from the Yellow River, leading to the collapse of countless old city foundations, burying layers of soil beneath the new city, the exact number of which is unknown. After earthquakes, several layers of the city became interlaced, and the underground has turned into a maze of silt and ruins. The Yellow River floods have occurred over ten thousand times in the past five hundred years, each time trapping many treasures in the mud, making it a goldmine for tomb raiders. In the ruins, as long as they explore a few hundred meters inward, they can return with their bags full.

However, the items that the oil bottle wants are in the deepest part.

“Do you not need help?” After the oil bottle spoke, Zhang Haike asked.

“You can’t help me,” the oil bottle replied. “You know nothing about everything here. Take what you can and leave quickly. Otherwise, danger does not only come from here; if the Zhang family finds out you are here, you won’t have a good ending.”

Zhang Haike and the others exchanged glances, and the oil bottle continued, “I didn’t want to say this. I thought it would be better for you to experience failure on your own, but you are too persistent and clever, and you actually made it down here. Now, I’ve said what I needed to say; whether you believe it or not is up to you.”

With that, he jumped into the mud and disappeared.

The others watched as bubbles surfaced from the mud, floundering for a moment before the oil bottle was nowhere to be seen, leaving them in stunned silence.

“What should we do?” one person said. “Is what this kid said true?”

“Whether it’s true or not doesn’t matter. If we listen to him, it means we’ve lost to this little brat. We’ve already lost enough face; I can’t swallow that. Why should we listen to him?” another person replied.

After another moment of silence, one of them cursed, packed up their gear, and suddenly jumped in.

Zhang Haike watched them jump in one by one, feeling a particularly bad sensation rising within him, but he still followed them into the mud, diving down.

The feeling of diving into the mud was strange to others, but Zhang Haike didn’t elaborate much; he only mentioned that he held his breath for about three minutes before grabbing a rope that led him to the side of a passageway. Holding onto the rope with one hand, he felt along the edge of the passageway as he moved forward. When he reached the top of the passageway, he floated up to explore the surface, discovering it was a well opening filled with silt, with a cobblestone floor outside. Several muddy monkeys were lying on the ground, gasping for air.

It seemed to be a family courtyard that had clearly sunk underground, turning into a cave, but the bonsai, rockery, and cobblestone floor still remained.

The torch has been lit, and without careful judgment, one might think this is just a very small stone hall. The flood has swept away two houses, and the collapsed outer wall now lies in the courtyard, tilting to become the ceiling. Zhang Haike wiped the black mud from his face and noticed that, apart from the few of them, there was no sign of the “dumb oil bottle.”

“Where is that kid?” one of them asked, pointing to the side. On the ground, there was a muddy footprint leading into the darkness where the torchlight couldn’t reach. Zhang Haike wanted to follow immediately but was pulled back: “That kid told us not to follow him, or it would be very dangerous. He said that path is only passable for him.”

Zhang Haike, feeling impatient, thought to himself that this kid really doesn’t care about his life, refusing even help. This was typical childish behavior. He said, “After all, he is our kin. Regardless of his intentions, we can’t let him go to his death.”

Zhang Haike followed the muddy footprints, and a few of them went along, discovering that in the corner over there was still a hole leading to another gap. Zhang Haike remarked that this ancient city was completely buried in silt; in some places, the silt had completely turned into soil after hundreds of years, while in others, it remained viscous. Only in many larger, enclosed ancient architectural remains was there any air. The early explorations by the Zhang family had already established pathways between the navigable routes, hiding ropes in the silt that could be felt by anyone entering the muck, allowing them to reach another room before suffocating. Some rooms were too far apart, and the previous explorers had used the method of digging theft tunnels to progress. In short, due to the complex geological conditions in the ancient city, it had become a system composed of theft tunnels, ropes hidden under silt, and various pathways.

The ancestors of the Zhang family had initially used a networked exploration method, but in the later stages, all routes converged into one, clearly indicating a specific purpose. This was because at the beginning, this group was only focused on collecting wealth, but later, they discovered a secret among the treasures they had gathered, which led them to concentrate on exploring that secret.

In the corner of that room was the entrance to a passageway. After entering, they found themselves in a dry ancient ruin that had already collapsed halfway. They could see a ceiling that was sharply carved, with half of it buried in the soil, and the entire top was slanted.

This was a chamber, adjacent to a garden, appearing to be a building of a wealthy family, sturdy due to their affluence. Although it had collapsed in the flood, many shapes had been preserved.

They saw two forks in the path here, with the tomb passage continuing forward and splitting into two. From the muddy traces, it was easy to identify which path the “dumb oil bottle” had taken, but Zhang Haike realized they could not follow.

Because at the openings of these two paths, one was large and the other small. The large one was of normal size, while the small one could only accommodate someone the size of the “dumb oil bottle.” Although the others looked like they were not much bigger than the “dumb oil bottle,” they definitely could not squeeze through.

Zhang Haike was puzzled. After carefully inspecting the small theft tunnel, he realized it was a necessity because around this theft tunnel, there were four pieces of bluestone in the soil, indicating it was a drainage passage with a fixed diameter that could not be widened.

No wonder the “dumb oil bottle” said that only he could pass through.