Act 1
- Opening flashback to Black Manta and his father in a tender teaching moment
- Manta finds the wreckage of the sunken sub as he ends up finding his father’s body to grieve him as he never had the chance to in the first film
- Funeral scene for Manta Sr with Black Manta being the only one in attendance
- Aquaman is a celebrity at this point with the public not only because of the first film but because of Justice League, as we see Arthur in action in the surface world doing some heroic stuff like saving boats
- Diner scene with Arthur, Mera, Atlanna, and Tom
- Arthur is back in Atlantis as its king as he performs his duties as ruler of the Seven Seas by trying to repair damaged relationships with the other kingdoms which we saw in the first film
- Then we get our first scene of Arthur in Atlantis visiting his brother Orm in Atlantean prison. Orm is still angry at Arthur for existing as he feels he should still be King and not Arthur. Arthur is angry at Orm for murdering innocents and trying to take over Atlantis and damage the surface world that he loves and is also a part of and he can't help the fact he was born. General tension between these 2 brothers like think Thor and Loki.
- Aquaman and Mera discuss Atlantis and duties not only as King but being a hero also to the surface world (ie. as Aquaman in JL, being a hero to the humans) wondering if he really can do both
- Manta finds his way to Atlantis as he ends up capturing an Atlantean soldier as he tortures this Atlantean soldier for information namely just who Aquaman really is; Manta learns the identity of Aquaman and after he tortures the soldier, he ends up killing him.
- More drama on Arthur’s part about Atlantis and his ability to lead as he has a Council Meeting with the other Kingdoms. While all this happens, Black Manta attacks with an army. While this happens in Atlantis, we also get a simultaneous coordinated attack on the surface world by having Tom’s lighthouse being under attack too.
- Fight scene between Black Manta and Atlanna, Arthur's mother; Atlanna outmatched but she doesn't die
- Manta then proceeds to kill Tom with his father’s blade; Arthur arrives to see his father die right in front of him courtesy of Manta
- Manta escapes
Act 2
- Funeral scene for Tom with just Arthur, Mera, and Atlanna
- Tension between Arthur and Mera concerning what to do about Manta. Arthur wants to kill him but Mera pushes to reinforce and prep Atlantis for another attack.
- We get a scene of Orm this time with Vulko as Orm is angry with Arthur for not being able nor being prepared to lead their Kingdom as King, and how Orm should still be king. At this point Arthur has lost his father and he's trying to repair what relationships he has left with his family. Orm then begins to understand and sway but still remains firm in that he doesn’t think Arthur is ready.
- Vulko asks Arthur to stay in Atlantis because their people need him more than the surface world does especially at this moment and they need him to help rebuild Atlantis' defenses.
- Arthur hangs up the Aquaman outfit
- Arthur leaves Atlantis again to go back up to the surface world as he goes back to the village he was in, in Justice League, to get away however someone has followed Arthur. Someone emerges from the water and we think it's Arthur but we see the onlooker’s face turn and we see Manta’s shadow.
- Arthur finds the village people slaughtered as he becomes distraught and leaps back into the ocean to head back for Atlantis. Arthur then starts searching the seas for Manta. Arthur eventually finds Manta lying in wait for him.
- They fight, but Arthur lets his emotions get the better of him. Arthur basically is dominating the fight physically until Manta's army surrounds him as he's heavily outnumbered. Black Manta gets the upper hand and beats on Arthur until Mera shows up to make the save and rescue him.
- Manta realizes what Mera truly means to Aquaman
Act 3
- Arthur finally begins to grieve his father with Mera
- Arthur goes back to the Atlantean prison as he talks with his brother Orm again. Arthur is then starting to accept the duties of Atlantis and what not. Arthur decides he can't keep running from his problems anymore as he doesn't want Orm to stay in prison. Orm however still thinks Arthur is irresponsible and foolish for ignoring his duties and going after Manta alone. These 2 brothers finally come to an understanding with each other about their fathers and what they mean to each character.
- Manta then begins to plan his 2nd attack on Atlantis
- Aquaman begins to accept his duties further and goes to help amongst his own people
- Black Manta begins the attack
- Arthur is about to go up against Black Manta again but has one last conversation with his brother Orm. He knows they don't see eye-to-eye but he hopes that one day they can agree as men and as brothers. He fought Manta once and badly lost so for that he needs Orm’s help to defeat Manta. Arthur basically keeps up with his appeal by saying to Orm "for the people of Atlantis, for all that you and I both care about: Orm, brother, will you help me?" Arthur presents Orm's remade Trident, the one he broke in the climax of film 1. it would be great if this is the first time he calls Orm brother.
- Next scene we get the Battle for Atlantis underwater
Aquaman, Black Manta, Mera, Orm fight. Everyone is fighting everyone here as it eventually leads up to it, just being Aquaman vs Manta one on one mano e mano. Mera and Orm meanwhile are fighting Manta's army and have defend Atlantis while Aquaman and Manta duke it out.
- Aquaman stops fighting and forgives Black Manta. Arthur’s words cause Manta to pause and Arthur puts his hand on Manta’s shoulder.
- Manta considers for a brief moment softening towards Arthur but then he hardens up all over again and then cuts off Arthur’s hand.
- Arthur wounded continues to fight and eventually gains the upper hand
- Eventually Black Manta is defeated and Arthur has him sent off to prison above in the surface world.
- Aquaman and Orm begin an uneasy alliance. Orm acts as a steward of Atlantis when Arthur is off doing Justice League stuff or general Aquaman stuff in the surface world. Orm gets to care and guide Atlantis and Arthur accepts the responsibility of King while still having the freedom to be Aquaman.
- The ending we get the final shot of Aquaman sitting on the newly built throne of Atlantis
Post-credit scene
Black Manta is broken out of prison by none other than who? None other than Lex Luthor. Lex offers him a place in this League of their own. Lex is with Deathstroke as the 2 of them break Manta out.