Thanks to the starting point Chinese Guang Aiyang, honest strong, first-class general commander, local bug monthly pass.

Thank you for the recommendation votes of the book friend 161212164041827, Island Island, badass with certificates, and Ghost Brake.

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Due to their inexperience, human forces blindly used flamethrowers underground. Although it is indeed very powerful, it also accidentally causes a lack of oxygen in the underground confined environment.

As a result, the human defenders, who reaped the consequences, had to be forced to retreat backwards.

The zombie side took the opportunity to attack in a big way, and successfully advanced a large section into the underground shelter of humans.

And after mastering this Achilles heel of human beings, the Corpse King also controlled the zombies under his command, especially the fire mutants, to prevent fire everywhere, and wantonly accelerated the consumption of limited oxygen in the underground space.

As a direct result, several underground shelters of the Steel Fortress were occupied, and most of the area was occupied.

Humans were able to retreat to a few large vents or simply to the entrances and exits. Further down is the ground.

So the Corpse King seemed to see the hope of successfully capturing the Iron Keep again, and instantly seemed to be stimulant, not only dispelling the previous idea of retreating, but also mobilizing more troops in the rear to participate in the attack.

What the Corpse King didn't know at this time was that it was this decision that ultimately caused the death of more than 100,000 zombies in the next few hours of scorching battles. and passivity due to insufficient forces in the process of a full-scale retreat further along.

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Yes, the human forces have finally regained their defensive line after retreating to an oxygen-rich area.

The personnel on the ground even quickly brought in many large blowers, ready to supply air underground.

But at this moment, Chen Yuan used the walkie-talkie to inform: "Don't turn on the blower that is already in place!" If the underground is filled with air again, it will tell the zombies that we have a way to overcome the lack of oxygen! I'm afraid zombies will be scared away! So let's make the zombies happy for a while! Units defend themselves in place with the help of air from vents or entrances and exits. Keep luring the zombies to attack! If necessary, some places can be abandoned, and the bottom line is not to let zombies rush out of the ground! ”

"Understood!" The troops replied one after another.

Qin Cheng smiled while shooting at the zombies in the distance: "Haha." Chen Yuan, you're too ghostly! ”

Chen Yuan smiled and said, "There's no way, if we don't take advantage of the fact that we don't kill a little more zombies now, when they retreat, we estimate that it will still be very difficult." ”

Qin Cheng laughed: "Haha, I like it!" ”

So, on the human side, the battle was deliberately put under the water, and the battle lasted from 2 a.m. to 5 a.m.

After three hours of fighting, as soon as the Corpse King counted, he found that he had lost nearly 230,000 zombies from the beginning of the battle to the present, but in terms of attack, there was never much progress!

They haven't even met a normal, combat-ready human! This is too fake!

So the Corpse King finally realized that he couldn't go on like this, and simply chose to retreat.

Moreover, this time, it completely abandoned the attack on the Iron Fortress and prepared to withdraw to Qiha City.

The corpse king is bitter in his heart! It's so hard, so hard that you can't bite it, but you also break your teeth!

Of the 2 million zombies brought, there are only 670,000 left, not to mention teeth, and even the bone marrow is almost lost here!

If they don't retreat now, they won't even have the strength to protect them from retreating.

So don't fight, resolutely retreat! Big deal to come back next summer!

So, under the control of the Corpse King, the entire zombie army began to retreat.

But is it that easy?

Chen Yuan, who was fighting, suddenly saw the zombie group retreating, and immediately understood that the zombies were going to run.

Chen Yuan immediately ordered all the blowers on the ground to start.

If you don't start it, most of the underground shelters are still full of carbon dioxide.

And the temperature is also very high, and they all feel the heat wave when they stand here at the exit.

But with the sound of the blower "buzzing......", a large amount of air from the ground is poured into the ground.

These airs are rich in oxygen, which is the guarantee for the activities of human warriors underground.

At the same time, the air of more than minus ten degrees Celsius is blown into the ground, and at the same time, the heat of the underground is blown away.

Under the blowing of the large blower, the fires that had not yet burned out were ignited again, and rushed to the direction of the zombies with high temperatures.

This time, the zombies are also self-defeating. Although a large number of sparks are not as exaggerated as flamethrowers, they also cause some damage to the retreating zombie hordes.

And behind, the human army quickly followed the cold wind to kill.

These cold air, which was more than ten degrees below zero, almost froze the entire underground world dug out by the zombies in only half an hour.

Nowadays, even if the zombies hide underground, they are greatly affected by the severe cold.

The zombies are simply chased to the sky and have no way to enter the ground!

It was only at this point that the Corpse King realized that launching an attack from underground to deal with the defenders in the Iron Castle was simply the stupidest attention.

Because their firepower is several times greater than that of the human defenders in other places!

Perfect for fighting in such narrow passages!

If it weren't for the certain zombies left by the Corpse King decisively, their losses would have been even more heavy.

Eventually, 650,000 zombies, under the control of the Corpse King, returned to the ground and began to retreat south.

Qin Cheng asked, "How is it, do you want to chase it now?" ”

In fact, at this time, Chen Yuan and Qin Cheng were still cleaning up the scattered zombies left here by the Corpse King underground.

This time the Corpse King did a very clever approach, it did not gather the 20,000 zombies left behind, so it is estimated that they will soon be wiped out by the forces that humans are chasing them.

Instead, spread all the zombies evenly. Or even hide in a hole or corner in the tunnel. As a result, the human coalition forces had to disperse their forces and carefully search for the huge tunnels dug out by the zombies. Because Chen Yuan and the others were also afraid that if the inventory was not clean, the zombies behind would suddenly run out and sneak into the steel castle.

As a result, the pursuit of the human coalition was greatly slowed down.

But in fact, Chen Yuan and they have been prepared for a long time.

On the road in the steel fort, the 1st and 2nd Brigades of the Field Infantry and the Fire Support Brigade of the Self-Rescue Army, which have completed the fully mechanized upgrade, are ready to go at this time.

And as soon as the zombies escaped from the ground, the military intelligence department of the Steel Fortress had actually discovered their movements.

However, Chen Yuan said at this time: "Don't be in a hurry, let the zombies run for a while, and let them leave the special alert range of the Steel Castle!" This will allow the residents of the other underground shelters to return to the surface and start giving birth with peace of mind! ”

The so-called special alert range is a radius of 50 kilometers from the Steel Castle, beyond which the Corpse King will no longer be able to control the zombies from attacking the Steel Castle.

(End of chapter)