During the Qin Dynasty, he was in charge of the net.

Li Ji felt as if he had forgotten something, but the situation now left him no time to think about it.

He had just passed through a narrow crevice and looked back to find that his two companions were no longer behind him.

Even more dangerous is that his gas cylinder now contains less than half the oxygen. Once the oxygen runs out, he will die of suffocation in a short time.

Just half a day ago, the four of them arrived at Jiuxue Tianchuang, one of the most popular diving training sites for divers in China.

Nine-Hole Skylight is a stunning lake with a radius of no more than 100 meters and light blue water.

Beneath the nine skylights lies one of the world's most beautiful underwater landscapes, with intersecting stalactites and sapphire blue waters—scenery that no surface landscape can match.

And so, Li Ji and his group of four agreed to sneak into the Nine Caves Skylight.

Li Ji is a photographer who has taken many underwater photos and has extensive diving experience, thus serving as the diving leader among the four.

The other three are Shen Qingchi, a female Chinese language teacher and Li Ji's girlfriend.

Wang Ke, male, is a leader of a small company and Li Ji's childhood friend.

Xia Yue, female, Wang Ke's girlfriend.

Just before the four went into the water, Xia Yue looked at the deep lake and felt fear in her heart. She decided to stay on the shore and wait for the other three.

So the three of them, with Li Ji leading the way, Shen Qingchi in the middle, and Wang Ke, the least experienced, at the back, entered the cave under the Nine-Cave Skylight.

As they dived into the lake, the three were immediately awestruck by the stunning scenery at the bottom!

Sunlight shines through the lake, creating dappled patterns of light in the cave. The light is refracted and scattered, making it almost feel like a dream.

Inside the cave were stalactites and stalagmites formed over thousands of years. They were all different shapes and sizes. When Li Ji shone his flashlight on them, the different stalactites showed different textures and color changes. The unique visual effect made him very happy.

The first half of the journey was very easy for the three of them, and Li Ji even took many underwater photos using the camera in front of him.

When they reached a depth of 57 meters, the three of them had to pass through a U-shaped passage, which was narrow and only allowed one person to pass at a time.

Li Ji, as the team leader, was the first to enter the U-shaped passage.

However, after swimming two-thirds of the way, at the bottom of the U-shaped passage, Li Ji was horrified to find that the original passage was now filled with sand and silt.

This resulted in a passage that could barely be passed by one person being completely blocked and unable to pass.

Li Ji suppressed his fear and told the two people behind him the news.

Upon hearing the news, Shen Qingchi and Wang Ke were extremely panicked. Wang Ke urgently asked Li Ji what they should do now.

Looking at the blocked passage in front of him, Li Ji knew that he only had two choices now.

One option is to continue forward, clearing away the sand and silt.

The second option is to return via the original route.

According to their original diving route, they have already swum more than halfway to their current location. If they return the way they came, they are very likely to run out of oxygen on the way back.

Finally, after a difficult decision, Li Ji chose to continue forward, clearing away the sand and silt.

The process of clearing sand and gravel in the water is very physically demanding, and this physical exertion will accelerate the consumption of oxygen.

Therefore, Li Ji decided to clear the sand and gravel by himself, while Shen Qingchi and Wang Ke stayed in place to conserve their energy.

Li Ji calmed himself down and began manually clearing away the sand and gravel.

Fortunately, the sand and gravel were relatively small and brittle, so the cleaning process went smoothly.

About twenty minutes later, the previously blocked passage was basically clear.

Li Ji was overjoyed. In order to check whether the passage was completely clean, he chose to go through it first.

Li Ji passed through the narrow passage without any trouble. Just as he was about to turn around and let Shen Qingchi and Wang Ke come over, he found that there was no one behind him.

It turned out that while Li Ji was clearing the sand and gravel, Wang Ke was terrified by the dark river water, the closed rock walls, and the constant underwater pressure. Unable to withstand the immense pressure, he chose to return the way he came without informing Li Ji and Shen Qingchi.

As Li Ji cleared the sand and gravel, the silt in the water was stirred up, reducing visibility to less than one meter.

It was under these circumstances that, by the time Shen Qingchi came to her senses, she realized that there was no one in front of or behind her anymore.

Unable to determine the direction, Shen Qingchi mistakenly took the direction Wang Ke had left as the direction he was heading.

With no one around, Shen Qingchi chose to swim forward, heading towards Li Ji, unaware that this was the way back.

Li Ji was unaware of these things.

So when he finished clearing the sand and gravel blocking the passage, he realized that he had no companions behind him.

Looking at the murky river water, Li Ji once again faced two choices.

The choice is to go ashore alone first, or to go back and find companions.

Li Ji looked at the oxygen tank dial; the oxygen that was originally plentiful was now less than half full.

It should be noted that, according to the plan, they should consume less than half of the oxygen during the entire diving process, with the other half being reserved for backup.

This shows that Li Ji consumed a lot of oxygen while clearing the sand and gravel.

At this critical moment, Li Ji decided to return to find Shen Qingchi and Wang Ke.

As the team leader, he didn't want to abandon his companions and go ashore alone.

After deciding to return, Li Ji immediately changed direction and used the guide rope to search for the two in the original direction.

At this point, visibility in the water is already very low. If you are even slightly distracted, you may not be able to spot the guide rope and thus lose your way.

After swimming for about twenty minutes, Li Ji finally saw a figure.

He swam over and discovered that the person was Wang Ke.

However, he noticed that Wang Ke's condition was very strange. The respirator in his mouth was nowhere to be found, and the oxygen in the oxygen tank was almost empty.

It turned out that after Wang Ke decided to return alone, he panicked and kicked the top of the rock wall with his flippers, making the originally clear path he came from muddy.

Under these adverse conditions, Wang Ke's oxygen cylinder accidentally became entangled with the guide rope.

This caused Wang Ke, who was already panicked, to become completely disoriented.

Fear caused him to breathe rapidly, and the rapid breathing caused his oxygen tank to quickly run out of oxygen.

Finally, the oxygen that was originally enough for several hours was used up in less than twenty minutes, and Wang Ke died of suffocation.

Li Ji suppressed his grief, knowing there was one more person he had to find: Shen Qingchi.

He noticed that the water ahead was much clearer than this side, which meant that Shen Qingchi hadn't swum back yet and was still trapped nearby.

With this in mind, Li Ji had no choice but to abandon Wang Ke's body and instead begin searching for Shen Qingchi.

He changed direction again, this time choosing not to take the originally planned route, but instead heading upstream.

He guessed that Shen Qingchi might have lost her way because she couldn't find the guide rope, and since he hadn't encountered her before or after, he suspected that she might have accidentally entered some underwater secret chamber.

Li Ji swam upwards, searching for Shen Qingchi's figure along the rock face.

He swam through two stone caves but did not find Shen Qingchi.

Li Ji was already in despair. He regretted bringing Shen Qingchi to the Nine Caves Skylight. He should have been more ruthless and rejected her back then.

Just when Li Ji was feeling utterly hopeless, he noticed a flashlight flashing diagonally upwards.

Li Ji was excited and quickly swam in that direction.

Sure enough, Li Ji found Shen Qingchi there, and there was actually an air chamber there.

An air chamber is a closed stone chamber containing a small amount of oxygen.

Shen Qingchi found this air chamber by chance and is resting there.

After finding Shen Qingchi, Li Ji was overjoyed. He hugged Shen Qingchi, and the two of them leaned on each other with their heads above the water. They were so excited that they couldn't speak for a moment.

After a while, Li Ji told Shen Qingchi that Wang Ke had been entangled in an oxygen cylinder and had eventually drowned.

The two were heartbroken. Neither of them had expected that what was supposed to be a cave diving trip would end up like this because of the sand and rocks blocking the way.

Time passed by unnoticed. Shen Qingchi leaned on Li Ji's shoulder. Li Ji turned to look at her, and her face had become very pale.

He knew that Shen Qingchi was becoming weak due to insufficient oxygen. Since the air chamber was not large, the carbon dioxide exhaled by the two of them would cause the oxygen content to decrease further.

If the oxygen level drops below 10%, both of them will suffocate.

At this moment, Li Ji made a decision: he would leave the air chamber to Shen Qingchi while he searched for an exit to seek help.

Shen Qingchi knew she couldn't stop him, so she had no choice but to pull Li Ji back and put her own oxygen tank on him.

"I will wait for you."

This was the last thing Li Ji heard Shen Qingchi say after he submerged in the water.

After diving into the water, relying on his memories, Li Jizhen found the guide rope again.

After finding the guide rope, Li Ji swam towards the exit like a madman.

He found the exit in just a few tens of minutes. In order to get back to rescue Shen Qingchi as soon as possible, he did not linger at the decompression point and returned to the shore.

A decompression point is a location designed to reduce nitrogen levels in the body, allowing the body to remain at different pressures for a certain period of time.

Therefore, when Li Ji came ashore, Xia Yue, who was on the shore, was shocked to see him like this.

Because at this time, Li Ji's diving suit was torn in many places, his body was swollen all over, and his face was terribly pale, as if he had been soaking in the water for several days and nights.

After getting ashore, Li Ji's first action was to have Xia Yue call the police for rescue. Then, he took a spare air cylinder and prepared to go back into the water.

"Are you crazy? You've developed decompression sickness, and you still want to go back into the water?"

Li Ji didn't offer any further explanation and jumped back into the water.

At this point, after Li Ji and the others had swum around in the cave of the Nine-Hole Skylight, the water quality inside had become extremely turbid, and the visibility was less than half a meter.

In this situation, Li Ji's flippers accidentally got tangled in the guide rope.

Li Ji made a tough decision and simply took off his flippers and discarded them.

Fins are a device that helps divers swim, which means that the journey ahead will be a great test of Li Ji's physical strength.

"Wait for me!"

Li Ji was already going crazy. He repeatedly crashed into the rock wall. The sharp stone pillars tore through his diving suit, and the icy river water poured into his clothes, rapidly depleting his body temperature.

Li Ji disregarded everything else; he had only one thought in his mind: to find Shen Qingchi.

Because there was no guide rope in the air chamber where Shen Qingchi was located, Li Ji spent a lot of time searching for him.

Finally, after feeling his way up a rock face, Li Ji spotted Shen Qingchi.

He ascended frantically, handing the spare gas cylinder connector to Shen Qingchi, but all he received in return was cold indifference...