The seas are angry, my friend! Black Manta is, too. He wants more than just revenge against Arthur Curry. That much is clear in the first teaser trailer for Aquaman and the Lost Kingdom. Yahya Abdul-Mateen II is back to destroy Jason Momoa’s hero and everything he cares about. That will lead to all out underwater war, in a battle that will see two brothers forced to work together to save their world.

Don’t worry, though, Aquaman has some more help—like a giant translucent war seahorse.

We now have our first real look at director James Wan’s long-awaited sequel to his 2018 smash hit. This Aquaman follow-up looks much darker in tone and story than the first, but with the same kind of vibrant energy.

Alongside its teaser, DC Studios also shared an official synopsis for Aquaman and the Lost Kingdom that provides the best idea yet of what we’ll see when we return to the waves. From an unlikely family reunion to powerful artifacts, this movie will bring us all out undersea chaos.

Having failed to defeat Aquaman the first time, Black Manta, still driven by the need to avenge his father’s death, will stop at nothing to take Aquaman down once and for all. This time Black Manta is more formidable than ever before, wielding the power of the mythic Black Trident, which unleashes an ancient and malevolent force. To defeat him, Aquaman will turn to his imprisoned brother Orm, the former King of Atlantis, to forge an unlikely alliance. Together, they must set aside their differences in order to protect their kingdom and save Aquaman’s family, and the world, from irreversible destruction.

Aquaman in his armor holding his trident with his hair moving in the water in The Lost Kingdom
DC Studios

DC also provided updates for its many returning characters. They offer even more clues about the Aquaman sequel’s plot. Turns out Arthur Curry and his Queen are new parents. (Aww.) We hope that burning house in the teaser doesn’t mean Aquaman’s own dad won’t be around to babysit his grandson. (Oh no!) From DC:

All returning to the roles they originated, Jason Momoa plays Arthur Curry/Aquaman, now balancing his duties as both the King of Atlantis and a new father; Patrick Wilson is Orm, Aquaman’s half-brother and his nemesis, who must now step into a new role as his brother’s reluctant ally; Amber Heard is Mera, Atlantis’ Queen and mother of the heir to the throne; Yahya Abdul-Mateen II is Black Manta, committed more than ever to avenge his father’s death by destroying Aquaman, his family and Atlantis; and Nicole Kidman as Atlanna, a fierce leader and mother with the heart of a warrior. Also reprising their roles are Dolph Lundgren as King Nereus and Randall Park as Dr. Stephen Shin.

DC Studios

Plus, look at all the pretty sea creatures in the Aquaman teaser! And, we guess, even the not-so-pretty ones. They’re pretty cool, too. Maybe that’s why they’re so angry. We can’t wait to find out why when Aquaman and the Lost Kingdom dives into theaters on December 20.