The mid-nineteenth-century Southern Continent was God’s lost Eden in the Southern Hemisphere.

This vast landmass was tightly embraced by the blue Indian and Pacific Oceans, with mild, spring-like weather year-round and sunshine pouring generously over every inch of ground. The endless savannas of the interior boasted rich, lush grass, rolling like a dark green velvet carpet all the way to the horizon; the lush Great Dividing Range in the east was thick with forests and gentle streams, nurturing countless forms of life; and the mines of the west and south held endless treasures—gold, coal, and iron ore lay buried in staggering, seemingly inexhaustible quantities. But what made this continent most famous across the world was its endless flocks of sheep.

Back then, the Southern Continent was truly a nation “riding on the sheep’s back.” The Merino sheep brought by colonists found an ideal home here: no harsh winters, no dangerous native predators, and green grass all year. They multiplied freely across the plains. Tens of millions of sheep wandered lazily across the grasslands, their white wool covering the earth like clouds. Every year, the clipped wool filled one ocean freighter after another, bound for Britain, Europe, and the entire world. Wool exports alone gave the people of this continent a life of comfort and prosperity. Landowners held vast pastures, lived in spacious, elegant mansions, and enjoyed lavish lifestyles; even ordinary herders lived securely from shepherding, with relaxed smiles on every street corner. People firmly believed this land was an everlasting treasure, a rare paradise on Earth.

For millions of years, the Southern Continent’s ecosystem had evolved in isolation, developing unique rare species—kangaroos, koalas, platypuses—and forming a fragile but stable natural balance. Yet this balance had a fatal flaw: an extreme lack of resistance to invasive species. Like a pure body with no immune defense, it would spiral out of control instantly if foreign organisms invaded.

Precedent had already made this clear.

European rabbits, first brought as pets for amusement, escaped into the wild and multiplied explosively without natural predators. In just decades, they numbered in the billions, stripping the land bare, digging burrows, and turning vast grasslands into desert. Even camels, imported for transport and later abandoned, overran the central deserts, exceeding one million in population, destroying vegetation and stealing water sources. Cane toads, foxes, feral pigs—every invasive species had disrupted the continent. Yet people never truly warned themselves, dismissing each crisis as a minor nuisance. They never imagined that a real, apocalyptic disaster was hiding in the shadow of ocean-going merchant ships, creeping closer silently.

The source of the catastrophe was a few insignificant mice.

An ocean freighter sailing from Europa, loaded with industrial goods, glided into Sydney Harbor on the Southern Continent. After months at sea, the dark, damp lower decks were cluttered with cargo and debris, making perfect hiding spots for small creatures. No one noticed, deep in the crevices of the hull, a small group of brown rats surviving on crumbs and wood, riding the waves across thousands of miles to reach this defenseless land.

Rats, tiny as they seemed, possessed far more destructive power than any other invasive species. Their ability to survive and multiply followed the cruelest laws of nature. Scientifically speaking, their reproductive rate was terrifying: a single female brown rat could produce six to eight litters per year, with eight to ten pups per litter. Young rats reached sexual maturity in just three months and began breeding again. In theory, the descendants of one pair could explode into thousands within a single year. Their burrowing ability was equally shocking: sharp incisors and strong limbs allowed them to carve intricate tunnel systems several meters deep. Where tunnels spread, the soil became hollow and unstable, collapsing under the slightest weight.

As omnivores, rats ate almost anything: grain, fruit, insects, roots, even bark and young wildlife. On the Southern Continent’s endless grasslands, tender grass roots became their easiest meal.

At first, no one cared about these tiny creatures. People remained lost in their prosperous, sheep-fueled lives, believing such small animals could never cause real harm. But within months, something horrifying unfolded.

With no predators, plentiful food, and perfect weather, the rat population expanded at a staggering, terrifying speed—spreading from the harbor coast to inland pastures, from a handful to thousands, then to massive, overwhelming swarms.

They came out at night, madly gnawing the roots of grass.

Without roots, pastures withered and died in vast patches. Once-green plains turned yellow and cracked before their eyes. They burrowed endlessly beneath the soil, weaving a dense network of tunnels that destroyed the land’s structure and drained its ability to hold water. Winds blew, sand filled the air, and fertile soil quickly turned to desert. Once-lush pastures became scarred, barren wastelands. Sheep starved and died en masse. Wool production collapsed. Farmers stared at their ruined lands, tears useless, their once-prosperous lives hanging by a thread.

Just as everyone was tormented and helpless against the rat plague,

an even more terrifying message arrived from across the ocean—thunder crashing over the Southern Continent.

At the same time the plague erupted in the south, Europa and Asia were struck by the Bubonic Plague—the dreaded Black Death.

Spread by fleas on rats, the infection caused raging fever, swollen lymph nodes, and internal bleeding, with an extremely high mortality rate. In that era of primitive medicine, it was nearly a death sentence. Reports told of European port cities losing tens of thousands of lives in months, streets empty, church bells ringing nonstop, entire cities becoming hell on earth. Major Asian trading hubs ground to a halt, bodies littering the streets, and panic swept across Eurasia.

For the Southern Continent, already torn apart by rats, this news was the final blow.

People stared at the rats covering every corner, the burrowed and desertified earth, and the horror of the Black Death.

All former peace and prosperity vanished.

In their place was bone-deep terror.

Once a paradise, the continent had become a prison surrounded by rodents.

The ecological collapse was still unfolding, and the shadow of deadly plague now loomed overhead.

No one knew if the catastrophe begun by a few tiny rats would soon consume the entire Southern Continent completely.