The once-bustling streets were now filled with countless corpses scattered across the ground.

The rapid death of so many living creatures in such a short time caused an overwhelming surge of negative energy in the environment. Some of the dead quickly rose again, turning into terrifying undead creatures. Those who had been high-ranking warriors, knights, or spellcasters in life continued to evolve into even more dangerous forms.

The once radiant magic towers, which stood tall and gleamed with colorful auras, were either overrun by hordes of undead that mercilessly slaughtered every living thing inside, leaving the towers to be consumed by death and decay, or the mages within had sealed themselves off, cutting all contact with the outside world, hiding in their last refuge and surviving on stored food. No one dared to conduct magic experiments like they used to.

As for escaping through teleportation portals…

Sorry, that's no longer possible.

Fourteen days ago, a dying archmage, believing the situation beyond salvation, used the power of the central tower to cast an immensely powerful binding spell. The entire city was locked in midair, 4,000 meters above the ground. All teleportation spells, flight spells, and even spells that slowed falling became ineffective. Even birds that flew into the spell's range would plummet straight down to their deaths.

The worst part? The spell would last for 100 years, meaning no one could escape.

The remaining survivors, unless they found a way to live for another century, were doomed to die of hunger, thirst, or old age. Of course, for those seeking a more "glorious" or thrilling death, they could choose to fight the undead in the streets or leap from the city's great height.

This is Planitia, the first floating city built by the combined efforts of archmages, and once the pride and center of Ael's magical civilization. But now, it's just a city on the brink of destruction.

In fact, similar things were happening on the ground in cities and villages.

A strange and terrifying plague had swept across the entire continent in just over a month. No one, whether the elite spellcasters of the floating cities or the warriors, knights, mercenaries, merchants, or slaves who served them on the ground, was spared.

No one knew where the plague came from or how to treat it. What the necromancers knew was that this horrible plague kept mutating and evolving. All treatments could only temporarily relieve the symptoms before the illness returned, fiercer than before. Even potions and spells once thought capable of curing all diseases only worked briefly at first, and soon death spread like a storm, killing thousands in no time.

Even the once god-like archmages weren't immune; many of them died in the plague.

Panic.

Fear.

Despair.

By now, social order had completely collapsed. The few lucky survivors on the ground hid deep in the forests or fled by sea, hoping to reach other untamed islands or lands to avoid the plague physically.

The powerful magical civilization the Ael people had built over 2,500 years was now on the verge of extinction under the onslaught of the plague. Even if the fleeing migrants survived, they likely wouldn't have the courage to return, nor the knowledge or resources to restore the old glory and prosperity.

Yet, the mages who fled would never have guessed that the root cause of this civilization-destroying disaster was just a traveler from Earth who accidentally sneezed due to a cold.

Yes!

Just a simple sneeze!

Unlike many other "travelers," Zuo Si crossed into this world in his physical body.

Given the scale of the plague's destruction, it was clear his body wasn't disinfected when he crossed over, bringing countless dangerous Earth viruses and bacteria. When these viruses and bacteria encountered the magical energy of this world, they mutated in ways no one could predict.

About two months ago, after working on creating a magical artifact for over 40 hours without rest, Zuo Si inevitably caught a cold, a result of overexertion and lack of sleep.

As everyone knows, colds lead to sneezing and runny noses. Especially sneezes, which spread droplets containing bacteria and viruses into the air, creating the initial infection. Every unlucky creature that came into contact with these droplets unknowingly became a carrier, spreading the disease further.

The people of this world, having never been exposed to Earth's mutated pathogens, had no immunity or antibodies.

Thus, a disaster broke out without warning.

In the basement, Zuo Si looked at the dissecting table used for necromantic experiments and the still-bleeding, foul-smelling corpse on it. Standing at just over 1.3 meters tall, resembling a ten-year-old child, he sighed softly. He tossed aside the scalpel, climbed onto a stool, and used what little clean water remained to wash the blood off his hands. After disinfecting himself thoroughly with high-concentration alcohol, he opened a journal and began writing in messy block letters.

"August 12th, 2535 of the Solar Calendar. The weather is gloomy.

It's been about a month and a half since the plague outbreak, and one year, nine months, and fourteen days since I arrived in this magical world.

There aren't many living creatures left in Planitia. Due to the massive death toll in such a short time, the city floating in the sky is rapidly transforming into a city of the dead. Even the proportion of negative energy in the environment is doubling. Soon, this place will no longer be suitable for the living and will become a haven for the undead.

From my last dissection and observations, I've concluded that this plague isn't caused by a single mutated virus or bacteria but by many—dozens, maybe even hundreds. That's why the so-called universal cure-all magic potions failed so quickly.

Some corpses have pustules on their skin, like smallpox or chickenpox, densely covering their bodies in a horrifying sight. Others have severe organ failure, with their respiratory systems collapsing and their lungs rotting away. The digestive systems—stomach and intestines—are covered in black spots likely caused by bacteria, stealing the nutrients meant for the body and spreading like cancerous cells.

Worse still, even after reanimating as undead, these corpses can continue to serve as infection sources for long periods. This means that the mutated pathogens won't die with their hosts; they've adapted to this magical world, becoming ten thousand times more dangerous than they were on Earth.

In this tower where I live, everyone—whether apprentices, warriors, knights, or slaves in the middle levels, or monsters and beasts in the dungeons—has died. Only I and the red female dragon, Vermes, who was captured from the other side of the portal and kept in isolation, are still alive.

As for my mentor and collaborator, Asta, the tower's owner and the head of the Necromancy Faction of the Magic Council, he disappeared before the plague outbreak. I suspect he took the notes he stole from an old wizard on the Faerûn continent and is now hiding somewhere, trying to turn his aging body into a powerful, immortal lich through a gruesome magic ritual.

But none of that matters now.

The floating city is sealed off by magic, no one can leave, and no one can enter. There's hardly any food left in the tower either; the storerooms have been contaminated by negative energy and the corpses of dead slaves.

Fortunately, I have a plan to escape.

Finally, I want to emphasize: I didn't mean for this plague to happen. It was a terrible accident…"