Story Premise:

This is a world where the entire ocean has become a warzone between the men above and the creatures of the great abyss.It began when the city of Atlantis ceased to be a myth. Across the waters of the Bermuda Triangle, figures emerged from the sea—mermaids, caught on the cameras of nearby cruise ships, military drones, and passing helicopters. The footage spread across the world within hours. What had once belonged to sailor’s superstition and ancient legend now stood before humanity in undeniable clarity. Every major navy on Earth responded. From the Americas to Russia, India, China, Japan, and beyond, the military powers of the world gathered to address the impossible situation unfolding in international waters. 

After days of tense deliberation, seven envoys were chosen to represent humanity. They were selected for their military standing, intellectual expertise, diplomatic skill, and ability to mediate between nations.

The seven set out aboard a small military vessel, crossing into waters that had already been declared the borders of Atlantis.

There, they were met by an army.

Thousands of Atlantean warriors surrounded the vessel, clad in gleaming armor and wielding tridents that radiated an otherworldly menace. Yet they had not come to declare war. They had come with a warning.

King Marinus of Atlantis revealed himself to the envoys and, through them, to the world. He spoke of an enemy growing in the deepest trenches of the ocean—an enemy so vast, ancient, and powerful that even Atlantis, after millennia of isolation, could no longer face it alone.

The Atlanteans called them the Wroltches, a word that translated most closely into human language as “the Wretched.” But humanity had known them by many other names across countless cultures: Sirens, Rusalka, Nymphs, and monstrous sea-beasts of legend such as the Kraken, Leviathan, Cetus, and others. They were creatures of the abyss, ancient horrors that the Atlanteans had fought and contained for centuries.

But the balance had broken.As the oceans became increasingly polluted by the actions of humankind, the Wroltches began to thrive. Corrupted waters strengthened them. Poisoned currents allowed them to multiply. What had once been contained in the abyss now surged upward in terrible numbers.Faced with extinction, Atlantis revealed itself.

The alliance between land and sea was not born easily. Many humans demanded the annihilation of the Atlanteans, fearing them as a threat to human sovereignty. Many Atlanteans, in turn, demanded vengeance against mankind for poisoning the oceans and causing the catastrophe that now endangered both worlds. Hatred, blame, and suspicion threatened to destroy any hope of unity before it could even begin.

Yet King Marinus and the leaders of humanity worked tirelessly to forge an agreement.

From these negotiations came the Oceanic Civility Accords, known as the OCA. The accords officially recognized Atlantis as a sovereign territory, granting it defined borders, political rights, and status as a monarchy under international law. In return, Atlantis agreed to cooperate with the nations of the surface in the war against the Wroltches.

Thus began the first great alliance between humanity and the people of the sea.

The navies of every major nation joined forces with the armies of Atlantis. Together, they waged war across the oceans. But human soldiers were vulnerable beneath the waves. Their numbers dwindled quickly, while even Atlantean forces struggled against the relentless hordes rising from the abyss.

Desperation gave birth to invention.

Human scientists and Atlantean scholars worked together to create a biological serum capable of granting humans traits from marine life. This serum became known as the Thalaserum.

When administered, the Thalaserum altered the human body, awakening aquatic characteristics based on deep genetic compatibility. Some gained the streamlined body and unmatched speed of the sailfish. Others developed the sharp teeth, heightened strength, and aggressive combat instincts of sharks. Some manifested the immense durability, coordination, and overwhelming mass associated with whales.

But the serum was unpredictable.Its success depended entirely on compatibility. A person’s DNA, ancestry, and ancient evolutionary links determined whether the Thalaserum would awaken any marine traits at all. For many, it did nothing. For others, it transformed them into something extraordinary.

Those who survived the process and gained aquatic traits became known as Finfolk.

At first, the serum was reserved for military use. Finfolk soldiers became invaluable assets on the oceanic front, capable of fighting alongside Atlantean warriors in depths where ordinary humans could not survive. As the war expanded and humanity’s desperation grew, the serum was eventually administered to civilians as well.By the time Earth’s population had fallen to roughly three billion, approximately forty percent of humanity had awakened marine traits through the Thalaserum. The remaining population remained fully human, biologically incompatible with the transformation.

Finfolk became more than soldiers. They became symbols of survival.

Governments treated them as national treasures. Their abilities brought fame, wealth, and privilege. Some became heroes, celebrities, military icons, or political figures. Others were exploited, studied, or controlled by the nations that considered them too valuable to live ordinary lives.

Decades later, the Thalaserum was discontinued. Nearly every living person had already been tested or administered the serum, and its effects had proven hereditary. Children born of Finfolk could inherit aquatic traits naturally, making further use of the serum unnecessary.

To marry into a Finfolk bloodline became, for many, the equivalent of winning the genetic lottery.

Through the combined efforts of Atlantis, humanity, and the Finfolk, the great war against the Wroltches was finally brought to an end. The creatures were driven back into the abyss, where they remained for years at a time, resurfacing only in smaller swarms and scattered attacks.For the first time in generations, the world entered an era of fragile peace.But beneath the waves, the abyss still waits.