Qu Ruilin's words immediately put me on high alert.

At that moment, we both knew how dangerous it would be for those who stayed behind.

Now that he has decided to proceed first, even if he doesn't intend to abandon me, the risks I will face next are enormous.

In other words, apart from the monkey, I cannot completely trust anyone in our team, nor will I take any risks for anyone.

Before I could even object, Qu Ruilin handed me the remaining oxygen tank he had on him: "These kinds of stone gates that block the way usually weigh several tons, or even tens of tons. Whether the first person to go through can open the gate is still unknown. I'll go check the mechanism first. If the gate can't be opened, you can take the remaining oxygen and find another way out."

I didn't believe Qu Ruilin's words: "What if it's opened?"

Qu Ruilin responded righteously and sternly: "I admit that I do hate you to the bone, and you know what you are worried about, but since I have agreed to raid tombs together, I will not disgrace the reputation of the Four Gates, as that would be disrespectful to our ancestors!"

I do not agree with this high-sounding explanation.

Although Qu Ruilin's act of leaving all the oxygen to me seemed very righteous, once he opened the stone door and then abandoned me, those few canisters of oxygen would only prolong my life by a few minutes.

I am not a desperate person like Ma Zhenhong and He Jinfeng, nor do I want to harm Qu Ruilin.

Similarly, I will absolutely not believe him.

Whether it's petty motives or excessive caution, I'd rather perish here than become his stepping stone.

Although that's what I was thinking, I couldn't say it out loud: "You saw it yourself, only one of us can get through! And the Duan family specializes in researching these strange and ingenious techniques in tombs. Who do you think has a better chance of breaking through the door?"

Qu Ruilin seemed to be thinking something, but I managed to persuade him, and he handed me the toolbox, saying, "Whatever you want."

I reached an agreement with him, and then stepped onto the stone slab.

Although I had the upper hand, I was also very uneasy, because if he pulled his foot back even slightly, I would be smashed into a meat patty by the hanging stone above.

If we can't open the tomb door in front, it means I've lost my usefulness to him, and we'll both die in the same way. But that doesn't matter, because if we can't open this door, none of us will survive.

My mind was preoccupied with Qu Ruilin's matter, so I was a little distracted. As soon as my foot landed on the threshold stone in front of the stone gate, I felt my foot sink.

"Click!"

Immediately afterwards, the stone guardian figures on both sides of me made strange noises at the same time.

The sound startled me so much that I broke out in a cold sweat. Only then did I notice that there was a hole about the size of a thumb on the side of both stone figures.

It seems I've just triggered a mechanism here. Luckily, it's old and the mechanism is no longer working.

Qu Ruilin also heard the sound of the mechanism: "What happened?"

"It's alright, there were mechanisms here, but they've already been destroyed!"

I looked at the tomb door covered with a layer of dirt, took out a brush from my toolbox, and started cleaning off the loose dirt.

In a short while, I found an oval-shaped strip pattern in the crack of the door and began to assemble the key with the shank.

The door in front of me is sealed with a self-locking mechanism.

The so-called self-closing stone is a tilted stone inside the door that fits in the shape of the Chinese character "卜" and blocks the gap between the two doors. Moreover, there is a groove under the stone, so once it is closed, it cannot be opened again.

Ancient tomb designers also had a survival instinct, so they couldn't possibly leave themselves inside the tomb to close the door. Thus, they designed the key with a nail.

When sealing the tomb doors, they would first close one door, then use a key-shaped stone to hold the stone slab in place and slowly close the other door. They would also adjust the position of the stone slab so that it would completely block the door from the inside. The holes in the tomb doors were originally used to use the key-shaped stone. After the stone slab fell down, they would use stone slabs or mortar to seal the gaps.

A typical shank key is a long iron rod with a "U"-shaped head at the top, resembling a fork. The head is used to loop a rope around a self-locking stone, allowing it to be pulled down from the side.

The key with the shank in my toolbox is made entirely of steel bars and is cut into several sections with connectors at the joints for assembly.

After assembling the key with the nail, I picked up a hammer and a chisel and began to dig at the sealing points on the door that had been filled with bluestone.

In the oxygen-deficient environment, I had to stop and breathe oxygen every few hits.

Perhaps out of desperation to survive, or perhaps because the ancient Indians who built this underground palace did not understand the mortise and tenon structure of China, the blocking stone was not wedge-shaped, but a straight piece. In about three minutes, I smashed the stone into the doorway.

Shining a flashlight into the crevice, you can indeed see the stone slabs standing upright inside.

At this point, I only had one oxygen cylinder left. After taking two deep breaths, I inserted the crutch key into it.

At this point, my lack of experience became apparent.

Although I managed to insert the fork into the doorway, it was completely useless.

Because I alone could not push the stone door open, and naturally I could not tie the rope to the stone.

I tried to push the self-locking stone with the key, but it felt like pushing a mountain. The groove under the stone held it firmly in place, and it wouldn't budge at all.

I struggled for over a minute, sweating profusely, but I couldn't do anything about the stone door.

In 1956, when Guo Moruo excavated the Dingling Mausoleum, he also used a key with a nail, but it took four adults working together to open it.

Qu Ruilin saw my movements from behind and knew that things weren't going well for me: "The oxygen is running out. If we can't open it, we'll have to retreat. We need to use our last bit of time to find another way out."

"It's too late! The entrance to this tomb passage is vertical; there's no choice but to keep going forward!"

I pulled out the key and threw it aside, then took out the hook and pin from inside.

A hook and loop device is essentially two wires, one end of which is a circle and the other end is a hook. The principle is similar to knitting a sweater; the two wires work together to insert the thread through the gap and entangle the contents.

This was my first time using a hook and loop, but I was pleasantly surprised by how successful I was at it, managing to tie the rope to the boulder.

The rope we use is a 12-strand high-strength polyethylene fiber cable. This fiber, along with carbon fiber and aramid, is recognized as one of the three major high-performance fibers, and its strength is about 1.5 times higher than that of steel wire rope of the same diameter.

I tied the rope around the self-closing stone, wrapped it halfway around the stone figure next to it, and threw the other end to Qu Ruilin: "The self-closing stone inside is about thirty centimeters wide. If we can drag it 15 centimeters horizontally, we can open a crack in the stone door."

Qu Ruilin nodded and wrapped the other end of the rope around his waist twice: "Come on!"