Card City, a rather wealthy mermaid city. It's not a big city, but it has a long history in the underwater world. Situated on a secluded seabed, it is surrounded by the ocean's north-south and north-bound currents, which carry a steady stream of nutrients. This place is rich in natural resources and nourishes the underwater inhabitants of this land and water.

The biggest feature of the city is that the large and small stone forest peaks that stretch outward from the center of the city are overlapping and scattered, and the terrain is called the urban pattern of the undersea karst landform in the words of the terrestrial people, which is very suitable for hiding the army and military facilities, so that the city has a kind of solemnity and sacredness shrouded in time.

Because of its superior potential in terms of natural resources and topography, the city has become a battleground for the wars of the merfolk under the sea. Now Kacheng, which has become a military town, is garrisoned by the troops of the Taiping Imperial City, but groups of whales have quietly gathered on the periphery of Kacheng, and a battle to defend it is about to begin. The history of the war in Kacheng is about to appear again.

The warm sunlight on the sea began to dim, and at some point the sun hid behind the dark clouds that surrounded it, and then it began to rain heavily. The wind signals whistled and shook the swaying waves, as if they wanted to tear each wave apart one by one.

Wind and rain are often mixed with the smell of war, like a kind of gunpowder smoke that fills the hearts of mermaid soldiers. Still, the desire for a truce seems so slim.

After figuring out the most likely route of attack for the whales, a group of summoned cuttlefish were the first to set up their formation. After the sea water was muddy, a group of more than 1,000 black dolphins took more than 1,000 combustible ice mines and gently placed them in suitable places, ready to serve a sweet potato feast to the invaders. But the arrangement of the pocket array was not yet fully completed, and a stout black dolphin clicked and clattered rapidly.

This is a message to tell your companion that danger is approaching and that they should retreat immediately. Originally, whales were not fish, and they were distant relatives of dolphins, and they had the ability to use sonar for positioning. Although the cuttlefish first created a visual barrier when setting up the formation, it did not work and was still detected by the whale's sonar, and then prepared to attack in advance. After starting to move forward, they are sensed by the dolphin with the same sonar ability, so the dolphin and the cuttlefish have to retreat back to defense.

The guards in the castle bunker held their breath and stared at the ink barrier made by the cuttlefish, some of them prayed silently, and some quietly closed their eyes and kissed the amulets and other things that their relatives had given them. But everyone understands how huge a whale's fins, mouth and belly are. What can stop the whale's mouth, what method can stop the ambition of the commander behind the scenes, maybe only fight at this moment, that is the hole card of the political movement, and it is also a sacrifice for maintaining peace.

The murky waters quietly dispersed, not yet clear, but black shadows could be discerned in the blur. A pair of crimson eyes could be seen on each dark shadow, and those eyes shot a chilling red light, which seemed to tell people a pain, a rage, a mania, an unspeakable fear and helplessness.

More and more whales appeared, and approached the defense line of Kacheng step by step, and soon entered the minefield that the dolphins had just arranged. Card City's first response was as usual with the whole city sounding the whale siren, and the subsonic whale siren resounded throughout the city. This has worked before, allowing whales to hear the sound and leave in fear. But today it failed to make the whales retreat for only one reason, and their ears were stuffed with something.

There was a deep, deep voice in the whale pack, a bit like a mechanical cow call, which was loud and terrifying. After that, it pressed towards Kacheng like a large dark cloud under the sea. After entering the minefield, the defenders of Kacheng detonated a combustible ice mine, and the rumbling thunder resounded in the water, and the roar of the storm on the sea surface intertwined, forming a tragic song that resounded throughout the sea. It also touches the hearts of everyone who loves life and cherishes peace.

The whales swimming at the bottom used their flesh and blood to block the bombardment of the ice mines below, and many of them had already fallen with serious injuries and sinks. Blood muddied the waters again, and the pelagic whales continued to move on, rolling like a carpet through the minefield. The area of the minefield and the number of ice mines must be limited, and the nearly 1,000-meter-wide line of defense is about to be torn open by whales.

The city of Casa had a dense array of firepower points on top of the towering rocks of the line, and these positions quickly began to assemble a mermaid cannon team consisting of the overlord squid and the king squid, which were the first and second largest marine invertebrates. It was an army with a cannon erected on each giant squid's torso and a mermaid gunner in charge of shooting. Can a team of thousands of cannons hold off thousands of whales? This is a severe test of the courage and mind of the mermaid gunners.

After the order to fire the cannon was given, the merfolk cannon team activated the cannon ignition switch on the back of the giant squid. With the muffled sound of the water, the cannon shoots a lethal wave of energy at the whale. This is not a hard warhead, but a shock wave with concussive energy. Whales moving close in on the battle line were not fatal if they were hit by this shock wave, but it made them very uncomfortable and uncomfortable, so those who were hit fled backwards.

One group of whales retreated, and the other came up. Wheel wars go one after another. But while advancing, the whales also received instructions from the behind-the-scenes manipulators, and set up their own positions as they advanced. Little by little, a wall of whales was erected, and the soldiers of the Kacheng Guards knew in their eyes that the whales were ready to use that powerful move that could shatter the target with ultrasonic focusing.

So the mermaid artillery team increased their firepower even more, and they had to defeat the whales before they could use that ultrasonic focus. In the roar, the huge body of the whale group obviously formed a great advantage, like a natural meat shield to withstand the attack of the cannon. The formation continues.

Even though the shelling of Kacheng is intensive, more and more whales are appearing. It seems difficult to stop their build-up, especially the blue whales. They are the largest overlords of the ocean, creatures at the top of the food chain.

What a terrifying madman and madman it must be to manipulate so many whales precisely and on a large scale behind the scenes and make the controlled forget their fears, sometimes there is only a thought difference between a madman and a genius, and the difference is only to do something that others praise or hate.

Under the bombardment of the merfolk army, the wall surrounded by whales was finally completed, and the next step would be to counterattack. They are arranged from top to bottom from left to right under the control of the behind-the-scenes controllers to form a huge spherical wall with a certain arc, which is about more than 1,000 meters wide and almost as high as the depth of the water.

Ultrasonic focusing is a tactic that uses the ability of whales to emit ultrasonic waves with the power to shatter objects, so that each whale in the whale group emits ultrasonic waves towards the same point at the same time, and uses the combined force of ultrasonic waves to destroy the target. At this moment, the formation is complete, and it is the turn of the whales to fight back.