The battle continued, and the monster army's footsteps had been completely stopped by the continuous artillery fire, and it took several hours to advance a distance of less than a kilometer.

If they continue like this, they will not be able to reach Lin'an, and they will all be wiped out.

Lu Kai stood in front of the electronic sand table, and the 3D projection technology realistically simulated the terrain within 100 kilometers of the entire Lin'an City.

Every road, canyon, and mountain is extremely meticulous and ingenious.

The army of monsters came from that place, facing the endless plain, and it was undoubtedly a live target in the face of the army's fierce artillery fire, and it could not rush at all.

But the uneasiness in his heart grew stronger and stronger, and he always felt that something bad was about to happen.

On the battlefield, the battle situation is changing rapidly, and every small detail cannot be overlooked.

Especially in this situation, if this monster army breaks through the defense line, tens of millions of civilians behind it will become food for the monsters.

He didn't dare to be careless.

It seemed that the situation was very good, but Lu Kai was restless, and the source of the underground vibration was like a fish in his throat to him.

"Xiao Liu, on the side of the Earthquake Bureau, has the specific monitoring report come out?" Pacing back and forth in the command room, he couldn't help but order.

"I just asked ten minutes ago." Xiao Liu's face was embarrassed, and when he saw that Lu Kai's eyes were wrong, he quickly changed his words, "I'll go and urge again!" ”

Lu Kai anxiously paced back and forth in the command room, waiting for news.

"It's out, it's out!"

Xiao Liu walked in quickly, with a happy look on his face, "The monitoring report is out, and the Earthquake Bureau will report to you in real time." ”

"That's not going to get through yet!" Lu Kai replied.

After a short time, the picture on the big screen in the command room changed, and a bald middle-aged man appeared, standing in front of the camera.

"Chief, I am Sun Yaxiao, director of the Lin'an Earthquake Bureau."

The look on his face was a little heavy, and Lu Kai chuckled in his heart.

"What's the situation!?" He asked hurriedly.

Sun Yaxiao turned his body sideways, revealing the big screen behind him, and said: "The source of the vibration is 300 meters underground, fifteen kilometers away from Lin'an City, that is, at the foot of our army's first line of defense now. ”

Sun Yaxiao pointed to the map behind him, and the location was clearly marked with a big red cross.

The other staff officers in the command room also stopped their work at this time, and their eyes gathered here, staring intently at the big screen.

"According to our monitoring, the tremors are still moving in the direction of Lin'an City, at a speed of about 300 meters per hour."

A straight red line appeared on the map on the big screen, pointing straight to Lin'an City.

"Later, we used the latest technology to monitor the situation at that location intensively, and we got this picture."

Sun Yaxiao waved his hand, and a picture changed on the screen.

"We found that there was a long passage underground, about 50 meters wide and 30 meters high, and the edges were so neat that it was not caused by the movement of the earth's crust."

"What?"

"How so?"

There was a lot of talk in the command room, and they were all shocked by the news.

"Quiet." Lu Kai shouted loudly, and then smiled at Sun Ya on the big screen and said, "Keep talking." ”

"Yes." Sun Yaxiao nodded, frowned, and continued: "Later, we found out that at the end of the passage, that is, the source of the vibration, there was such a sound wave coming out. ”

Then, the sound came from the stereo, small and noisy, like spring silkworms gnawing on mulberry leaves, and like sand rolling on glass.

"We amplified the sound 150 times to barely separate it from the ambient background noise."

"Later, we used the latest imaging technology to find out such a scene."

Sun Yaxiao waved his hand again, and a black and white picture appeared on the screen.

There are hundreds of black spots on it, densely packed and layered, almost all in one.

"This black spot, we suspect that it is a worm about a meter in size, they are constantly digging, and at the same time secreting some kind of substance to strengthen the channel!"

Reaching this conclusion, a cool breath rose in the hearts of everyone.

It turned out to be a bright plank road, and a dark Chen Cang.

It turned out that the monster army, rushing forward in the face of artillery fire, turned out to be this idea.

Attract the attention of the humans while attacking from underground and breaking through to the city.

If this project is really completed, then Lin'an City will really be destroyed.

Once the monster breaks through to the city, the army will be attacked on its back, so will it be possible to really fire cannonballs into the city?

"What's going on!? It's such a big thing, and you only found out now? Lu Kai scolded angrily, he finally knew the source of the uneasiness, it turned out to be such a plan, he still underestimated these monsters a little.

"No, we ......" Sun Yaxiao wanted to argue, but in the end she didn't say anything, lowered her head and looked ashamed.

"Well, I don't blame you." Lu Kai sighed and calmed down his somewhat anxious mood, this bad news caused him to be a little unable to control himself.

"Continue to monitor, don't relax, and report as soon as there is a new situation." He commanded.

The priority now is to find a way to solve the problem, not to find the person responsible.

"Yes." Sun Yaxiao's face was serious, and he replied immediately.

The call was cut off, and the staff officers gathered around to discuss countermeasures.

"They're underground, and we can use giant ground-penetrating bombs to hit them and destroy them in one fell swoop!" A staff officer touched his chin and made a suggestion.

"No, the giant ground-penetrating bomb will only go about 30 meters deep into the ground at most, and this depth is not enough to hit it." Another staff officer objected.

"I think so, such an attack can cause a shock, maybe it can collapse the passage."

"We can wait until they get to their feet and dig up before attacking, that attack is more effective."

"No, that's too passive, at that time, we will be attacked on both sides, and once something goes wrong, it will be a situation from which we will never recover!"

The staff officers each put forward their own ideas, and there were different opinions, but there was no perfect solution.

Lu Kai touched his chin and pondered, this is indeed a difficult problem, it is difficult to deal with, and if you are not careful, it will cause a big disaster.

Moreover, according to the speed at which this passage extends, it will arrive at Lin'an City in dozens of hours.

Maybe you don't get to Lin'an, and when you reach the foot of the second line of defense, the monsters will attack the rocket artillery position, and that situation is also serious.

"Everyone, be quiet."

After a moment, he tapped on the table and said, "On the one hand, use the giant ground-penetrating bombs to carry out a focused attack on the area, and at the same time concentrate the artillery fire on the area, and on the other hand, the battle line retreats on all fronts to prepare for the worst." ”

After another pause, he said, "Let Tan Wenwei come to me for a while." ”