Although he knew these scrolls were made of human skin, Li Decha still persuaded Rouyi to take them, because they might record a period of human activity that had never existed in the world.

"This is proof of the Stone City people's existence. If we get out of here, these will be valuable historical materials," Li Decha advised.

Rouyi was finally persuaded, and the two re-rolled the scrolls and carried them on their bodies.

I seemed to understand why the City Lord was so fond of things made of human bones. There was nothing on this island but stone. Whether metal, silk, or jade, it all had to be transported from the mainland by sea. In ancient times, when sea transport was not developed, the difficulty of transportation was naturally self-evident.

When everyone else was using stone tools, the ruler used unique human bone implements, which could both show power and demonstrate majesty.

No wonder the murals depicted the scene of the ruler punishing slaves. I guessed that these human bone crafts all came from those killed slaves.

We ran out of a door behind the creepy stone hall. We thought we could escape the terrifying atmosphere of the stone hall, but who would have thought that behind the stone hall was a cemetery, with hundreds of stone coffins neatly arranged on the ground.

The stone lids of several stone coffins were not closed properly. I glanced inside and saw a corpse that had long been dried and completely dehydrated. The corpse was relatively well preserved.

I suddenly thought of the pyramids. If the pyramids built by the Egyptians were mausoleums, then the pyramids here should also be mausoleums. After all, Stone City could not compare to ancient Egypt. With a limited population, building such a large pyramid had already overdrawn all the people's strength. Naturally, it was impossible to build a pyramid for each generation of City Lords.

So, I guessed that this pyramid was a public burial ground (a cemetery would be more appropriate). After the old City Lord died, he would be embalmed and sent to the pyramid…

At this moment, Jennifer reminded us that the oxygen content of the oxygen tank was not enough, and we needed to return to the submarine immediately.

So, we returned the way we came and returned to the submarine.

This trip back and forth exhausted me. I thought to myself that my physical strength was really getting worse day by day.

Fatty pointed to my full head of gray hair and said, "Two hours of exploration, one hour of return trip, this efficiency is too low. We have to quickly find the Young Master the underwater gate, otherwise the Young Master may die of exhaustion first."

Fatty was right. After the submarine struggled upstream, especially during the high-speed spin, my eyes aged rapidly. I began to see things up close becoming blurred, and I couldn't see things far away either.

My physical functions had also declined significantly. The exploration of Stone City just now had almost drained my physical strength.

I said to Fatty, "My current physical strength is not enough to support me going back and forth anymore..."

Streamlining the team was imminent.

Currently, there were six oxygen tanks. If we wanted to improve efficiency, we would only arrange for two people to accompany me to find the underwater gate, one person carrying two oxygen tanks. In this way, we could have six hours of activity time.

But choosing two out of five, who to choose?

Fatty was in the best physical condition and had rich combat experience. He was naturally the best choice. Li Decha, as the only man among the remaining four, was also a good choice.

However, Li Decha was not particularly enthusiastic about finding the underwater gate. His attention was completely attracted by the scrolls, and he was focused on deciphering the hieroglyphs on the scrolls.

But then again, in terms of physical strength, Li Decha was actually not as good as Jennifer.

Rouyi said without thinking, "I'll go!"

Jennifer shook her head and patted Rouyi on the shoulder, "Look at the old man's appearance, he may need someone to carry him at any time. It's already difficult for one person to carry two oxygen tanks weighing dozens of pounds. I'm in better shape, I'll go."

Han Yu said, "This arrangement is actually the most scientific, let them two go."

I was surprised that Han Yu didn't have any objections to the combination of Fatty and Jennifer. However, judging from Han Yu's attitude towards Jennifer along the way, it seemed that she didn't regard Jennifer as her rival in love.

In times of emergency, Han Yu could always maintain a calm mind.

……

After the six oxygen tanks were refilled with oxygen, I had almost rested. I got up and prepared to go out with Fatty and Jennifer.

Rouyi suddenly hugged me from behind and said gently and affectionately, "Young Master, you will find a way out, you must come back alive..."

I turned around and hugged Rouyi as well, and said, "Don't be discouraged. I'm already very content to be able to escape death and see you again..."

Rouyi had made many efforts that I didn't know about in order to facilitate this ocean expedition. I owed her a lot.

"Let's go."

I waved to Rouyi and the others. Rouyi said to me, Fatty, and Jennifer, "You must come back!"

Last time we explored, we determined that there were no clues about the underwater gate near the stone hall, so this time we chose another path.

Fatty led me and Jennifer along the inner wall to another area of the inner city, this area was behind the cemetery. In order to make me feel more relaxed, Fatty carried three oxygen tanks by himself.

"Hey—" Fatty pointed to a small mound not far away and said, "There seems to be a cellar there."

My eyesight was failing. I walked closer and realized that this was not a small mound, but the above-ground part of the cellar. The place I thought was a mound had a raised entrance.

Impaired vision made me half-blind.

Fatty moved away the stone lid covering the entrance, and a staircase appeared in front of us. After confirming that there was no danger inside, Fatty went down first, and Jennifer and I followed closely behind.

The cellar was pitch black. Fatty had prepared special magnesium light sticks in advance. We used the light from the light sticks to see the situation in the cellar clearly.

"Damn, there's actually a passage underground!" Fatty said.

This was not a simple cellar, but an underground passage leading to nowhere. We still hadn't figured out why the Stone City people built such an underground passage.

Fatty said, "Young Master, do you think the passage to the underwater gate might be somewhere in the underground passage?"

I nodded and said it was possible. The most mysterious stone hall in the Stone City on the ground had already been explored by us, and there was no strange "door" or anything like that. In that case, the underground passage might be connected to the location of the underwater gate.

So, Fatty held up the light stick and led us into a deep passage.

There were not many forks in the passage. We only encountered one fork at the beginning, and we chose a direction to move forward. After that, we never encountered any more forks. The passage was very long and dark. We groped forward in this long, dark passage.

There were no lights, candlesticks, or torches in the underground passage. There was not even any lighting design on the walls of the passage. Fatty couldn't help but complain, "This was designed for the blind."

We had been walking in the passage for an hour, but we still couldn't see the end.

As we walked, Fatty suddenly asked me, "Young Master, have you smelled a fishy smell?"