Under the dominion of Olympus, Hera sought to keep the gods in check by constructing the floating city-state of Elysium above the Aegean Sea, where she refined divine power through the sacrifice of mortals. When her older sister was sold and met a tragic end as a sacrifice, a young woman named Thalia infiltrated the city-state disguised as a cupbearer, navigating a web of intrigue involving four demigods bound by divine oaths: Leon (son of the God of War), Kaelen (God of the Sea), Orion (God of the Sun), and Zeno (Crown Prince of the Underworld). Though they initially viewed her merely as a sacrificial offering, they gradually found themselves captivated by her. Venturing deep into the Mist-Shrouded Canyon, Thalia forged a pact with Eris—the lingering spirit of a Titan—gaining the "Power of Ash" capable of tearing through divine barriers. The four demigods broke free from their shackles and joined forces to dismantle the sacrificial system, establishing the City of Ash, a realm where mortals and demigods stood as equals. Enraged, Hera mobilized the celestial armies to lay siege, bringing the world to the brink of an all-out war between mortals and gods.
