In Aquaman 3 the oceans are once again at the center of a cataclysmic battle, this time involving new, dangerous powers that threaten not only Atlantis but the entire planet. Jason Momoa returns as Arthur Curry, the now fully established King of Atlantis. The film introduces Timothée Chalamet as Arion, an enigmatic and powerful sorcerer who claims to be the rightful ruler of Atlantis, descending from an ancient line far older than Aquaman’s. Chalamet’s Arion is not an outright villain but a complex antihero with a deep connection to the mystical forces of the ocean.

The trailer begins with Arthur leading Atlantis into a new era of peace, working closely with Mera (Amber Heard or her replacement, depending on casting) to unite the underwater kingdoms. However, their peace is shattered when strange, magical phenomena begin to affect the oceans—severe storms, disappearing sea creatures, and mysterious structures rising from the depths.

Arthur and Mera investigate, uncovering ancient texts that tell of Arion, a lost prince with god-like abilities tied to the sea’s most primordial forces. Believed to have vanished thousands of years ago, Arion suddenly reappears, challenging Arthur for the throne of Atlantis. He believes that the kingdom has lost its way, disconnected from the ocean’s ancient power, and only through him can true balance be restored.

Arthur, initially dismissive of Arion’s claim, soon realizes that the sorcerer’s powers are far beyond anything he has encountered before. Chalamet portrays Arion as charismatic but mysterious, with a dangerous edge—he respects Arthur’s strength but is determined to take the throne, regardless of the cost.

The heart of the conflict lies in Arion’s belief that the oceans need to be cleansed of human influence. He sees the destruction of the environment and pollution as proof that mankind is unworthy of coexisting with the sea.