That was not right. Dragon City’s underground spirit energy transmission pipeline had undergone special explosion-proof treatment. Even if the spirit energy leaked and caught fire, it was rare for a chain explosion to occur.

Otherwise, during the Monster War, several of the densely populated streets would have blown up when a few dauntless monsters drilled into the underground system and bit through the pipeline.

What was going on?

Meng Chao had an ominous feeling.

He focused his attention on the soles of his feet. Then, through the soles of his enhanced combat boots, he keenly sensed a faint but strange vibration coming from the ground.

It was as if something like a tide was surging up from the depths of the earth.

“It stinks!”

Meng Chao narrowed his eyes and took a deep breath. He smelled a strong and familiar scent from the joints of the manhole covers on both sides of the street.

It was… the scent of a monster!

“Not good!”

Meng Chao’s pupils suddenly contracted.

At the same time, hundreds of manhole covers on the streets and alleys within a one-kilometer radius began to vibrate violently.

Before the ordinary citizens standing around the manhole covers could react, the covers were hit by waves of strange forces that originated from below the surface. They bounced up high and fell heavily from midair.

A few manhole covers smashed the roofs of nearby vehicles, creating, while others smashed into car windows, making sharp sounds.

There were also a few manhole covers that almost hit the ordinary citizens, so the whole thing caused everyone to jump in shock.

The ordinary citizens had no time to react as black “fountains” rushed out from hundreds of manhole covers.

“Squeak, squeak, squeak!”

The black “fountains” let out ear-piercing cries and split into torrents, rushing toward the area where the crowd was densest.

The crowd that was caught off guard was immediately torn apart by the black torrents, and many of them let out miserable cries.

“Yes, it’s the fierce-toothed rat!”

“Rat tide! A rat tide has erupted!”

The Fierce-toothed Rat was a rodent-type monster, and it was an unrated existence at the bottom of the monster pyramid in terms of combat strength.

However, with their strong reproductive ability, they could give birth to dozens of babies in a litter. Their survival rate was extremely high. They could possess basic destructive power in three months and reproduce again in six months. That allowed their population to increase exponentially.

In addition to the rodent-type monsters’ unique ability to burrow and bite, they were strong enough to destroy everything that humans had carefully buried underground, such as underground optical cables, underground spirit energy transmission pipelines, and a large number of facilities attached to the underground transportation track.

Therefore, the rat tide, which was formed by thousands of rat-type monsters, was definitely one of the most troublesome threats to humans during the Monster War.

From a certain perspective, the threat of a rat tide was even greater than the threat of Apocalyptic Beasts like the Crystalline Nine-headed Dragon.

Since the Apocalyptic Beasts were huge and obvious targets, humans could spot them more than a hundred kilometers away from Dragon City.

Once the Apocalyptic Beasts showed signs of advancing toward the main city area, all the railway guns in Dragon City would turn around at the same time and bombard them.

All the Deity Realm fighters would also be on high alert. They would ensure that the clueless Apocalyptic Beasts would fall into the vast ocean of Deity Realm power.

However, the rat tide was different due to the rodents’ underground burrowing abilities and stealth.

The rat tide would usually erupt directly from below the main city or even the downtown area.

Of course, humans could extinguish the rat tide.

However, it was difficult to guarantee that in the process of extinguishing the rat tide, they would not cause any collateral damage to the homes that they had worked so hard to build.

It was a principle of not acting against evil to prevent harm to innocents.

Moreover, it was easy to stop the rat tide, but it was not easy to completely eliminate it. As long as one-tenth of the rat-type monsters escaped to the depths of the ground and they were given a certain amount of food and time, they would be able to rise from the ashes and make a comeback.

Even Deity Realm fighters did not have a good way to deal with the rat tide.

Supposedly, Deity Realm warriors had the ability to penetrate the sky and the earth. Could they not dig three feet deep into the ground, turn the downtown area upside down, and dig up all the hidden rat holes?

After all, compared with the ferocious and awe-inspiring Apocalyptic Beasts, these rat-type monsters were insignificant.

Yet, everyone agreed that the threat of the rat tide was far greater than any other kind of beast horde!

Fortunately, with the end of the Monster War, it had been a long time since a rat tide broke out in Dragon City.

During the large-scale renovation of the old city in the past year, many originally chaotic urban areas had indeed been turned inside out.

Not only had the hygiene blind spots that were prone to the breeding of snakes, insects, rats, and ants been cleared out, but poison had also been placed deep underground to eliminate the rat infestation.

The people had also relied on the underground transportation lines to set up strict underground surveillance and early warning systems to ensure that when a large number of insects and rat-type monsters were prepared to gather deep underground, humans would be able to detect them in advance and nip the threat in the bud.

Aside from that, many mega corporations had also developed various small automatic rune machines that were suitable for underground operations.

For example, Thundercloud Technology had developed a small automatic rune machine that was equipped with the nervous system of a rat monster. It could simulate all the activities of a rat monster and even emit its unique aura. One could say that they were fighting evil with by having rats kill rats.

Under such protection, everyone thought that the rat tide was in the past and a broken nightmare.

They did not expect the rat tide to erupt again today.

Plus, it was in the downtown area of Dragon City, where the population was the densest, and all the vehicles were crowded there.

It happened at such a critical moment!

“How is this possible?!”

“Where did so many Fierce-toothed Rats come from?”

“Why didn’t the underground rat-killing device work? What about the early warning system? It would take at least a few days for such a large-scale rat tide to gather. Why didn’t the early warning system detect it in advance?”

People were both shocked and angry.

While the Monster War had ended, it had only been a year, and many people in Dragon City still had strong fighting instincts in their muscle fibers and nerve endings.

The individual fighting strength of rat-type monsters was far from strong.

If their academic results were slightly better, even middle school students who listened carefully in class and practiced diligently after could blow up the heads of rat-type monsters.

Facing the beast horde, many ordinary citizens pulled out their fists.

Coincidentally, there were many Azure Alliance members wearing blue armbands in the crowd. Without any hesitation, they stepped forward.

The elite soldiers of the various law enforcement departments also rushed toward the area.

As many superhumans activated their vitality magnetic fields to the limit, they spewed out wisps of spirit flames that were visible to the naked eye.

The ordinary citizens, who had been a little flustered by the rat tide’s attack a moment ago, calmed down.