Arthur Curry now sits uneasily on the throne of Atlantis. Ever since the events of Aquaman and the Lost Kingdom, the delicate balance between land and sea has been strained. Rumors of ancient powers hidden deep beneath the ocean floor begin to surface, and Arthur must contend not only with external threats but the internal doubts of ruling a kingdom divided by fear, tradition, and political ambition.

Black Manta, defeated but never destroyed, resurfaces with newfound allies. His thirst for vengeance has only deepened, and he seeks to harness forbidden Atlantean magic to unleash a force worse than any he’s wielded before. He forges an uneasy alliance with dwellers from the deepest trenches—creatures long kept secret—and together they aim to challenge Atlantis at its core.

Meanwhile, Mera finds herself navigating treacherous waters in her own right. Conflicted by betrayals, shifting loyalties in the Atlantean court, and the strains in her relationship with Arthur, she must decide whether to stand as queen, warrior, or both. Their son, still young, becomes a symbol of the future—and a target that both sides covet for what he might become. Arthur feels the heavy burden of fatherhood pressed against the demands of kingship.

As war looms, Arthur is forced into uneasy alliances. Old enemies may turn into reluctant partners. Even Orm, his half‑brother, might be called upon to defend Atlantis from falling apart. Their shared history, full of rivalry and resentment, now must give way to collaboration, or else all will be lost.

In the climactic final act, Atlantis teeters on the brink of collapse. Underwater battlefields erupt in chaos. Ancient magic awakens monstrous leviathans, tearing through the seas. Arthur will have to face the fact that to save his people, he may have to make the greatest sacrifice imaginable—perhaps even relinquishing the crown.

In the end, Atlantis survives, but it will not be the same. New leadership, new alliances, and new threats lie ahead. Arthur learns that sometimes a king must become more than a ruler—he must become a legend. And as the next chapter of the ocean’s story opens, the legacy of Aquaman will echo far beyond the waves.