The whole waterhole is fusiform, about 60 meters long and 145 meters wide, and the whirlpool is at the left end of the shuttle.

"This can't be a blue hole!" Officer Li immediately frowned. "This should be where the Dark River changes lanes again, and that huge whirlpool must be leading to another place."

"Such a big whirlpool, if you go down, it will be too dangerous." A policeman next to him chimed in.

Xiao Ling didn't speak, he looked around carefully with a flashlight, but he was quickly disappointed: the reality told him that this was indeed the end of the cave. Moreover, they did not find any forks in the road along the way.

"If this isn't the Blue Hole, then what are the people who came in earlier running for? And, until now, there has been no sign of their return. Li Xue said.

"Hold the grass, the meat ball, and the air is polluted again!" Liu Can on the side covered his nose and suddenly kicked Wang Hui.

", I didn't fart!" Wang Hui immediately glared at him.

"And where did this stench come from?" Liu Can smiled.

"Where does Lao Tzu know? Don't bury people all day long! Wang Hui walked away very unhappily.

There was no wind in this place, the air circulation was slow, and the rest of the people didn't seem to feel anything. But it didn't take long for them to smell the smell and fan their noses a few times with their hands.

Xiao Ling also smelled it, the smell was very light, and he couldn't smell it if he didn't smell it carefully, but it was indeed a stink.

"Hold the grass, whose eggs are expired!" Someone in the crowd laughed.

"Silly, how can there be eggs here, and they stink?" One immediately retorted.

"It must have been the egg that the person who came in front of me brought that was stink, so I threw it away." Another laughed.

"No, it doesn't smell like something rotten." Li Xue looked around with a flashlight, but she seemed to think of something, and then shouted: "This is the smell of hydrogen sulfide, everyone be careful!" ”

"Walter?" Wang Hui was like a cat whose tail had been stepped on, almost jumping up.

"How do you know it's hydrogen sulfide?" Luo Ziyan asked a little dazedly.

"Now, I'm sure this should be the Blue Hole!" Li Xue then explained: "Unlike the blue hole in the ocean, this blue hole belongs to the land blue hole. The water quality of terrestrial blue holes is usually divided into three layers, freshwater layer, hydrogen sulfide layer and oxygen-free layer. ”

"The hydrogen sulfide layer is mainly produced by the metabolism of microorganisms in the water, although it is highly toxic, but the content is very low, unless it is a special condition, it is generally not too dangerous."

"Normally, freshwater is drinkable, and although hydrogen sulfide is slightly soluble in water, it does not overflow hydrogen sulfide gas on the surface of the water because of its content. The situation here is different, because the huge attraction of the whirlpool brings the hydrogen sulfide in the middle layer to the surface, so we smell it. ”

"At the same time, this situation illustrates a problem from the side, that is, the location of the vortex is not a blue hole, it is just an outlet for the dark river."

"I don't know if you have noticed, the water flow of this dark river is actually not large, and it obviously can't meet the flow of the whirlpool, but the water level of this pool has always remained the same, which shows that there is still a water supply channel here!"

"And this just shows that there is indeed a blue hole here!" Li Xue talked eloquently and finally gave a conclusion.

Hearing this, everyone cheered.

"Beauty, you are simply the goddess of the school bully in my mind!" Wang Hui salivated and gave Li Xue a thumbs up.

"Xiaoxue, it's amazing!" Luo Ziyan said sincerely.

"Judging from the smell we smelled, perhaps because the suction force of the whirlpool was too great, most of the hydrogen sulfide layer that was sucked away was underwater, carried away in the form of an undercurrent, so there should not be a lot of hydrogen sulfide overflowing the water surface. However, everyone should be careful! Li Xue continued.

For this kind of geological common sense, although Xiao Ling is almost illiterate, his focus is very sharp, and it is in one sentence: "Xiaoxue, hydrosulfuric acid has a certain corrosiveness, so is the same for the hydrogen sulfide layer?" ”

"Yes!" Li Xue nodded and continued: "So, before going into the water, we have to find the specific location of the blue hole first, and we have to determine the thickness of the hydrogen sulfide layer before we can go down." ”

"Don't worry, the wetsuit still has a certain corrosion resistance, the only thing to pay attention to is not to expose your skin outside!" Officer Lee smiled. "What we brought was a special wetsuit, which was completely different from the ordinary wetsuit on the market."

"Officer Li, Xiaoxue is right." Zhu Ting, who had been silent, finally spoke, "No matter what has a specific use environment, once it exceeds its limit, accidents will inevitably occur, and I don't want everyone to have any accidents!" ”

"Now we don't know the concentration and thickness of the hydrogen sulfide layer, once the concentration is too high, or the thickness is too large, it is extremely dangerous!"

"So, I decided, before I go into the water, identify these two questions!"

"This is easy to do, after we determine the specific location of the blue hole, we will directly put a rope down." Officer Li is worthy of being the leader of the special police, and he is still calm and calm.

Once you have figured out the situation, the rest of the matter is much easier.

There is a lot of power in people, the lighting of the lighting, the diving of the diving, immediately start to work.

It didn't take long for Officer Li and his group to find an unfathomable underwater cave in front of the right side of the pool, which was about thirty meters away from the whirlpool.

The cave is large, more than twenty meters in diameter.

Officer Lee reported that because of the large distance from the whirlpool and the large entrance to the cave, the undercurrent in the water was very weak and was barely felt.

Then, Zhu Ting ordered to immediately test the depth of the blue hole and the hydrogen sulfide layer. Officer Li didn't talk nonsense, and then took out a climbing rope, tied a stone to the end, and hung directly into the hole.

One hundred and fifty meters long climbing rope, by the time the stone did not droop anymore, Officer Li only had twenty or thirty meters left in his hand!

"Officer Zhu, this hole is at least one hundred and twenty meters deep!" He shouted at Zhu Ting on the shore.

"Drag the rope a little longer, in case the stone gets in the way." Zhu Ting was a little uneasy and said loudly.

Of course, it was necessary for her to say this, after all, no one knew the structure of the cave.

As he said, Officer Li dragged the rope. After circling around the Blue Hole, he replied: "It should be the end, this position should be the Blue Hole's tunnel has changed direction." ”

"Hold the rope still and wait ten minutes before pulling it back." Li Xue shouted.

Except for a few people in the water, Xiao Ling and the others were all on the shore, and in addition to paying attention to the concentration of odors in the air, they could only watch from the sidelines.

After more than ten minutes, Officer Li took the rope back and returned to shore.

Upon closer inspection, they found that the position where the rope was somewhat discolored was between sixty-three and ninety meters.

"I'll it, the thickness of this hydrogen sulfide layer is really scary." A SWAT officer smacked his tongue.

"Fortunately, judging from the degree of discoloration of the rope, the concentration of hydrosulfuric acid is not very high, so it shouldn't have much effect." Li Xue said with a smile.

With this result, the stone in the hearts of the people was only half lowered. Then, Officer Li volunteered and took three people to investigate first.

"I really can't believe that because of a fart of the meat ball, we actually found the blue hole." Liu Can sighed.

"Get out of here, don't say that it wasn't put by Lao Tzu, even if it is, it's 'a fart'!" Wang Hui said to Liu Can.

"Can you two rest for a while?" Li Xue gave the two of them a big roll of their eyes, and turned back to Zhu Ting and said, "Sister Ting, if this blue hole goes on like this, except for these police brothers, few of us can dive so deep!" ”

"I've thought about this." Zhu Ting cut her hair and said with a smile: "I don't believe that the people who came in before are all professional divers!" ”

"If they can go, so can we. I'm almost certain that there is definitely a fork in the waist of this blue hole that leads to Yu Zhenxing's lair! Zhu Ting is sure to be authentic.

"Officer Zhu, you are amazing." Xiao Ling gave Zhu Ting a thumbs up. "As you said, it is impossible for Yu Zhenxing to make the entrance of the laboratory so complicated, with this kind of passage, it is a problem to transport those equipment and instruments in."

"yes, why didn't we think of this before!" Luo Ziyan patted her head and said hesitantly: "This can't be the pit that Yu Zhenxing dug for us, right?" ”

"Zi Yan, you said it all, those words were indeed left by your father, he couldn't have said nonsense." Li Xue soothed: "If my guess is correct, those equipment and instruments are likely to be transported from other places, but people can't go to that place!" ”