One hundred and eleven million years ago, Earth did not forgive weakness. The seas were higher. The air was heavier. Predators ruled ecosystems shaped by heat and volcanic breath. Survival was not a right. It was a negotiation with extinction. High above that world, carved into the face of a cliff beyond the reach of the wild, Sky City endured. Igzier was never meant to survive outside its walls. Raised within a civilization that prides itself on order and equilibrium, he learns too late that stability can be more dangerous than chaos. When the ruling Triumvirate moves to erase both him and the mentor who taught him to question the city’s balance, exile becomes his only path forward. Beyond the walls lies a world governed by different laws. Cold-blooded predators hunt by patience and heat. Volcanic ash can dim the sun for weeks. Entire ecosystems shift under pressure without warning. In this landscape, strength means nothing without adaptation. As ancient forces begin to stir and the delicate systems sustaining Sky City begin to fracture, Igzier must decide whether survival is enough — or whether the world that shaped him must be reshaped in return. WORLD OF TETHYS is an epic science-fantasy trilogy grounded in evolutionary realism, where environment is the true antagonist and civilization balances on the edge of extinction.