As Arthur Curry confronts the responsibilities of being King of the Seven Seas, a long-buried ancient power is unleashed. After witnessing the full effect of these dark forces, Aquaman must forge an uneasy alliance with an old enemy, and embark on a treacherous journey to protect his family, his kingdom, and the world from irreversible devastation.

Living on a rundown shipwreck, Mr. Fish one day discovers an energetic young sea dragon Pip - who had mistaken his home for a junkyard - pilfering his belongings. The heated argument that ensues leaves both their houses in ruin.​ But there is hope!