The Empire, the largest nation of the human race, dominates the western part of the continent of Ost. It has a long border to the north and south with the Eastern Kingdom and the Spirit Forest to the north, where the elven villages are located.

『Took advantage of the opportunity to invade the Kingdom, which had lost many of its Knights after failing to defeat a horde of Heavy Lancers.』

『Close the highway and blockade the elves who attacked the Frontier Knights led by the Grim Reaper in the Great Pit.』

Their hard-line behavior in recent years confirms their reputation as a 『ferocious power led by an ambitious emperor.』

Incidentally, in the previous case, the Empire succeeded in taking Landbarn from the Kingdom. However, the subsequent large-scale expeditionary force to the royal capital was forced to retreat due to a mysterious knight named 『Ghost Knight』 snipping their forces.

The next case plunges them into war after the elves rained down flames on the Northern city which is a part of the Empire’s territory.

『If the World Tree, which acts as the outlet of magical power to the earth, is destroyed, magic power will perish from the face of the earth and the world will perish!』

The elves said intimidatingly to the imperial Knights who started to counterattack, using the World Tree as a shield, but that didn’t stop the golem Knights, who are more than seventeen meters tall.

『Like I care! Burn the World Tree!』

The anger of the ruler, who had her city reduced to rubble and its inhabitants to charcoal, caused the elves to lose most of their population and their homes.

Incidentally, it seems that Mother Nature was far more resilient than the humans and elves realized.

The magic power in the underground sought other outlets, and now plants that would be called 『quasi-world trees』 have appeared in various places around the world.

「The roundtable meeting will now begin.」

And then present, in the round table hall in the palace of the imperial capital, the oldest city of the human race.

Starting with the emperor, the old woman and other senior vassals surround the huge round table, while a tall gray-haired gentleman stood alone in his seat and declared the start of the meeting.

「Now then, the principal of the Imperial Magic Academy, if you please.」

He is the Marquis, who presides over the highest decision-making body. He was once the commander of the expedition force to the Kingdom.

Although his reputation was lowered due to the failure of his expedition, he has accumulated achievements in diplomacy and domestic affairs, albeit modestly, and has returned to being 『one of the leading candidates for the vacant seat of prime minister』.

「After looking into it, it turns out that those magic beasts are indeed zombies.」

After the Marquis sits again, the principal, a scrawny old man, opens his mouth with a deep crease between his eyebrows. The attendees all distorted their faces after hearing his remarks and a small groan escaped from some of them.

『A strange magic beast that wandered out of the forest of spirits.』

The principal of the Imperial Magic Academy revealed the results of his investigation.

The other day, a medium-sized magic beast resembling a boar approached the imperial defense line built on the south side of the Spirit Forest.

Let’s rewind the time to that scene.

「What the hell is that?」

The first one to discover it was a C-class Knight pilot who was on a regularly scheduled patrol. It is not surprising that he involuntarily let out such a murmur.

The boar-shaped magic beast, which was moving slowly straight to the south, showed no signs of vigilance.

(…..That’s creepy.)

The impression he got from it was that of 『a mosquito being drawn to his breath』.

Avoiding melee combat due to a sense of discomfort, he had his 16-meter-tall humanoid golem hold a large stone lying in the wilderness and throw it at it like a projectile.

The stone, which was more than one meter in diameter, missed its target and slammed the back of the beast.

「No way… That can’t be…」

However, the boar-shaped beast showed no sign of pain and continued to move forward with only its front legs while dragging its immobilized lower body.

To the astonished pilot, his supervisor, who was also riding a C-class Knight and watching the situation nearby, shouted through the external sound system.

『Stay away from it! I’m going to call for backup now!』

The fact that he was able to immediately make a decision that would later be called a wise decision must have been because he had enough knowledge and experience to be called a veteran.

(It is most likely undead. If it turns out that they were zombies, then we would be in big trouble.)

The veteran pilot made a grim expression of anxiety and wiped the sweat from his forehead with the back of his hand, even though it was not even hot. In his long career, he had heard a certain story.

He rushed to his subordinates to see what was going on, and this time, he gave them instructions in rapid succession.

『Shields up! We’re surrounded! Keep your distance! Leave it to the B-class Knights to finish them off.』

And just like that, the 『alien magic beast』 was surrounded by a group of C-class Knights who rushed out from the encampment, and furthermore, it lost its head and stopped moving after being shot by B-class Knight’s long-range offensive magic attack that rushed in from the rear.

After that, the beast was strictly isolated and handed over to the professors and students of the Imperial Magic Academy who were dispatched from the Imperial Capital in a hurry.

『Zombies.』

It is one of those lifeless active entities called the undead. The reason why they are classified as such is because zombies have the characteristic of 『multiplying』.

『Those whose lives are sucked by zombies have a high probability of becoming zombies, depending on how bad the inflicted injury is.』

This is why in the past, a small town block, or even an entire village, was incinerated. And the veteran pilot probably knew about this.

『A disaster so great that it has the potential to destroy a country.』

Fortunately, the situation has never developed to such a level. Perhaps the reason is that both the attackers and the attacked were limited to the human race.

In this Ost continent, where magic beasts, large and small, run rampant, humans are not the only powerful forces. Therefore, they are forced to live in groups to some extent, but 『moving corpses』 are too conspicuous.

In addition, zombies do not hide and lurk because they are driven by hunger and it is easy to isolate them and dispose of them.

『Why is it only humans?』

There are various theories, but the most popular is that zombification is caused by high-ranking magicians who lost their lives in the past because of their strong attachment to life and because they are attracted to the lives of their fellow human race.

Incidentally, the elves have higher magical power than the humans, but no one knows of their race zombification since the elves never shared information about their race.

Here, we return to the round table meeting.

「There are no records of non-human zombies so far. However, I have found that the amount of magical power that a magic beast possesses can turn them into zombies.」

“It’s very intriguing, I tell you”, the principal said as he shook his head lightly. One of the old women in attendance then asks, while turning her thorny gaze toward him.

「Are these magic beast zombies attacks people?」

If they attack people and turn the people into zombies, it will become a horrifying incident. The other attendees, who can more or less guess the rest of the story, became even more grim.

「There’s a possibility that the elves somehow turned the magic beasts into zombies and used them as biological weapons.」

This speculation that came from one person spread like a wave caused by a big rock thrown into a pond, causing a commotion around the round table. In the midst of all this, the voice of the old warrior, the commander of the imperial knight order rang out.

「Even if they only attack other magic beasts, the Ost continent will surely be in turmoil. The daily life of us, humans will not go unaffected.」

The dead magic beasts that devour other magic beasts and the magic beasts that resist. The balance that had been maintained will be broken and some will even move from their nests and territories.

For large monsters that move in packs, a village is not even an obstacle to them.

「As the people in charge of this country, the first thing we should decide is how to respond to possible problems in the future.」

Those words sink the place into thoughts, and after a while, one person asks.

「Can the imperial army prevent these zombie magic beasts from getting out of the Spirit Forest?」

The old warrior raised his eyebrows, stroked his chin, exhaled heavily, and shook his head.

「If it’s only for a short period of time, then it’s possible, but it will be difficult the longer it lasts. No matter how closely we monitor the situation, there will always be a crack somewhere.」

Thus the options they can take are limited.

That is to 『Defeat all the zombified magic beasts by the hands of the human race, instead of leaving them to the magic beasts in the forest』. However, it is difficult for the human race to tell whether a zombified magic beast has turned into a zombie or not.

「So in the worst-case scenario, we have to incinerate the entire Spirit Forest, huh?」

Representing a common understanding, the old woman, who had first turned her thorny gaze on the principal of the Imperial Magic Academy, let out a groan.

The gazes of those around the round table naturally drifted to the person sitting on the seat of honor.

「It was us who started the war with the Elves and invaded the Spirit Forest. So we have a responsibility to finish what we started.」

After a short pause, a dignified middle-aged man spoke. The emperor then waves his right arm in the air and gives instructions to his ministers.