Arthur Curry (Jason Momoa) harus kembali melawan Black Manta (Yahya Abdul-Mateen II) yang sekarang semakin kuat dan menjadi ancaman besar bagi kehidupan Atlantis. Arthur terpaksa bekerja sama dengan Orm (Patrick Wilson) saudaranya sekaligus musuhnya demi nasib Atlantis.

Arthur Curry (Jason Momoa) must return to fight Black Manta (Yahya Abdul-Mateen II) who is now getting stronger and is a big threat to the life of Atlantis. Arthur is forced to team up with Orm (Patrick Wilson) his brother and enemy for the fate of Atlantis.