After a sudden change, Long Xiaoyun's face also changed.

It was at this moment that communication sounds came from Long Xiaoyun's terminal watch.

"Col. Long, we have a huge cave outside, with artificial signs inside, but we can't go down." This is Zhang 6's voice.

When the grenade exploded, gravel on the rock wall splashed, revealing the dark hole.

"It's really here!"

Tian Guo was overjoyed and urged Zhang 6 to go up and investigate.

When the two climbed up to the entrance of the rock wall, the entrance to the corridor appeared.

However, this entrance is different from the previous one. The entrance to the corridor is parallel, but this entrance is vertically downward.

Zhang 6 shone down with a military flashlight, which was unfathomable. The light source could not touch the bottom of the corridor, and the depth of the corridor could not be known.

It is not so much a corridor, but rather a deep well, poured by concrete, smooth around it, and has no focus to climb.

Tian Guo was experienced and picked up a piece of gravel and threw it at Jing Xin.

"Did you hear the echo?" Tian Guo kept listening carefully, but couldn't hear anything. The echo was too small, and it seemed that there was, and there didn't seem to be no.

"I heard a little, maybe after you throw it down for three seconds." Zhang 6 replied.

His body has been strengthened by seed essence, and his hearing has also improved to a certain extent.

The propagation of sound in the air is about 34om/s. The higher the temperature, the slightly higher the propagation.

This degree is too fast, only the free landing of the stone, so the deep well is at least about 30 meters deep.

With such a depth, the flying claws can barely fall.

"Do you want me to go in and detect?" Tian Guo suggested.

"The situation below is unknown, and the risk of entering rashly is too high." Zhang 6 said: "You can start with the previous corridor. I guess these corridors are mostly figured out."

"The mind is full of inspiration." Tian Guo praised: "How did you find that there is something wrong with the rock wall?"

"It's so concealed, the rock walls are bare, and there are not many weeds!" Zhang 6 said casually.

This is naturally not fooled.

Static photosynthetic warning, if you carefully investigate the matter of life and killing, clues will appear.

The corridor is sealed, and the remaining breath gathers strongly in the corridor, so the buzzing sound is particularly loud.

"What should we do now?"

"I'll talk to Long Xiaoyun first to report on the situation and see if they can find this place."

On the other side.

Long Xiaoyun still remembers to answer Zhang 6, the poisonous gas has begun to spread.

As a soldier, Dong Yi immediately ordered: "Close your breathing, the corridor is too small, don't panic, and retreat in an orderly manner."

The most feared thing is that this group of students is frightened and panicked, causing stampede and affecting evacuation.

While maintaining order, Dongyi and the other three organized experts and students to retreat and return to the entrance of the corridor along the way.

Just as everyone left the corridor, they ran towards the entrance.

There was a loud bang.

Everyone felt the earthquake in the corridor.

It's over!

Everyone was stunned.

A huge stone door fell from the corridor, just like the broken dragon stone in an ancient tomb, completely blocking the corridor.

Poisonous gas permeated.

That bad, disgusting smell came.

The young students were extremely frightened, their lips were white, without a trace of blood.

"What should we do? We can't get out, we will all die here!"

"Save us, I don't want to die here!"

"Let's find a way out, quickly... the poisonous gas will dissipate and we will all be poisoned to death."

"How could this happen? How could this happen..."

“…”

Voices of horror and despair came out from time to time.

Even Mr. Chen, the experts who had lived for most of his life, were pale and frightened in the face of death.

"Shut up! Take a deep breath and save more while the poisonous gas has not yet dissipated."

Dong Yi stopped shouting and rushed to the stone gate.

I saw him holding the butt stock and smashing it hard on the stone door.

The sound of the impact was very heavy and not loud.

Dong Yi frowned and turned around and shook his head at Long Xiaoyun and others.

If the stone door is not thick, the impact will not be so heavy. They can use firearms and then use brute force to break the stone door.

Now that the stone gate is too thick, Dongyi shook his head and told everyone that the brute force cannot be broken, the only way is to grenade.

But grenades must be used with caution.

Because they are in the corridor, if the explosion of the grenade is so powerful that if the corridor collapses, everyone will have to die here.

This corridor is the main corridor, and there is no second choice. No one can get out without breaking the stone.

Long Xiaoyun looked shocked and searched the corridor where there was nothing wrong several times. Why was it suddenly full of dangers?

This sudden change disrupted everyone's exploration plan and blocked their way to survive.

Be careless.

But now it’s useless to regret. The only thing you can do is to find a way to get out, otherwise you will be trapped in the corridor.

Dong San reacted quickly and took out three electronic instruments from her backpack. She counted the number of people, a total of 18 people.

He immediately said loudly: "The poisonous gas has begun to spread. I can't stand it. Just take a breath. The oxygen is not infinite!"

The three electronic instruments are military oxygen suppliers that can provide oxygen.

It’s just that oxygen cannot be supplied unlimitedly, it can only be provided for 15 minutes, but there are 18 people on site.

Dongsan is also unsure of how long can the three oxygen suppliers last.

"If you don't work, just blow up the stone door!"

Dong San showed a hint of determination.

But this explosion, no one can guarantee whether the corridor will collapse and the situation will become worse.

Poison gas came in the corridor, and the corridor was blocked by the stone gate again.

Everyone was like mice in the bellows, rushing and suffering in despair.

Long Xiaoyun thought that Zhang 6 was still outside, and there was still a faint signal at this moment, and he was about to communicate.

Bang!

Sudden gunfire sounded.

A military flashlight in the hand of a gray expert fell to the ground and then suddenly fell to the ground.

"Teacher Jin..."

The student screamed in horror, and the flashlight shone on Teacher Jin who was lying on the ground. He covered his chest and blood gushed out from his fingertips, dyeing the collars on his chest red.

ah……

A terrifying scream suddenly broke out.

"If you have an enemy, lie down..."

Dong Yi roared and rolled on the spot.

Bang!

The second gunshot sounded.

The bullet aimed at Dongyi, who was warning, and the fury bullets roared.

Seeing that the situation was not good, Dongyi rushed away.

Puchi.

Dongyi was not shot, but Dongyi, who was flying in, was hit by the bullets, and the bloody flowers exploded and blood mist sprayed.

"Enemy attack!"
To be continued...