Leo’s team were unconscious underwater as a mosasaur was targeting Mera, getting ready to eat her. But then, the mosasaur was mysteriously knocked out, saving Mera from certain doom. After that, the mysterious person rescued Mera and Leo’s team in the ocean and brought them to shore after that.
Arthur rose from the water and swam towards the shore. He looked up and saw the wonders of the place he was in. From prehistoric creatures to a natural landscape. It was a place unlike any other.
“Leo! Mera! Guys, where are you?” Arthur called.
He looked ahead and saw a mysterious figure carrying Mera and Leo’s friends to the sands of a remote island. Arthur swam as fast as he could while Mera and the rest woke up after being saved by the mysterious figure as it took off its mask.
Arthur arrived on land and ran, screaming, “HEY! GUYS!”
As Mera looked shocked, the mysterious person turned to Arthur, revealing themself to be his Atlanna, Arthur’s mother. He slowly stopped in shock, he couldn't believe his eyes. Atlanna survived and is indeed alive. She approached her son slowly to get a look at him.
“Arthur,” Atlanna called his son’s name.
“Mom?” Arthur said with tears in his eyes.
They finally hugged each other, feeling so happy that they were reunited for the first time in years.
Mikey cried with tears in her eyes, “Aww…”
“I know. It’s so beautiful to see a mother and son reunite after all these years,” Rarity said with tears in her eyes too. “C-Can someone give us a tissue please?”
“I wish I could, but they're all wet,” Pinkie grabbed all of her wet tissues from her hair.
Five minutes later, Queen Atlanna carried Mera, who was injured, while Leo carried Twilight, who had hurt her right ankle. They made their way inside a cave that Atlanna was familiar with.
“Thank you,” Leo bowed to her.
Atlanna nodded and Arthur asked, “Mom, how are you even still alive? What happened?”
“King Orvax sacrificed me to the trench, but I survived. I fought my way through as you did, and I ended up here,” Atlanna explained.
Casey complimented, “Wow, you are a survivor.”
“You've been alone down here this whole time?” Applejack asked.
“That must’ve been rough,” Mikey commented.
Atlanna helped Mera sit down. She then turned to Leo.
“Put her down here,” Atlanna ordered.
Leo gently placed Twilight down on a rock to sit on. He also removed her shoe and sock so Atlanna could take a proper look.
“Oh no, it appears one of the trench creatures clawed you.”
Rarity weeped, “Oh dear!”
“Should we be worried about an infection?” Twilight asked.
Atlanna answered, “Luckily, it only happened recently. Don’t worry, I know just the thing...”
Atlanna grabbed some ingredients and mixed them in a stone bowl. She also grabbed some seaweed from the lake. Atlanna smeared some of the stuff on Twilight’s ankle, then wrapped the seaweed around it.
“How does that feel, dear?”
Twilight answered, “It feels much better. Thank you, your majesty.”
“Just keep the wrap on your ankle for twenty-four hours, that should make it better.”
Atlanna then turned to her son. She apologized to Arthur, “You must forgive me. Forgive me for everything.”
Arthur replied, “This happened because of me.”
Atlanna placed her hands on his cheeks and told him, “Not for having you. None of this is your fault. I made a choice. I had to leave… to save you, to save your father.” Arthur understood her choice and Atlanna continued, “Tell me. Tell me about him. Is he...”
“He still walks on the end of the dock by the lighthouse. Every morning. Every day. Waiting for you.”
Rarity and Mikey couldn't stop crying after hearing that.
Atlanna felt teary-eyed and relieved that her husband from the surface world was still alive.
“Why didn't you ever come back?” Arthur wondered.
She took a deep breath and answered, “Because the portal that brought you and your friends here won't let us return.”
“You mean we’re stuck here?” Casey asked.
“Aww, horse apples,” Applejack frowned.
“Jungle wear is not a good look on me,” Rarity whined, her head immediately going back to fashion.
Atlanna continued explaining, “The trident is the only way back. But it is guarded… by the Karathen.”
Mera looked scared as if she heard the tales of a giant sea creature before.
“The what now?” Casey asked.
“The Karathen.” She turned to her son, “The creature from our legends, it's real. It lies beyond the waterfall.”
Everyone looked ahead to see the waterfall.
“We'll go with you. We can fight it together.” Mera suggested.
Leo nodded, “I agree. We'll all fight them together.”
“No,” Atlanna denied their request. “It's too powerful. I've tried many times over the years. The creature will only allow the true king to pass.”
“Leo, you and your friends have helped me every step of the way, but this is the part I think I need to do on my own.”
Leo and his friends understood his decision as Atlanna noticed, “You're afraid.”
“Yes. It's been a while since I was the king of Atlantis.”
“Good,” She smiled. “You're ready.”
Mera explained, “You may have been a king in the past with an arrogant demeanour, but now you need to move past that. And Atlantis needs something more than just a king.”
“What could be greater than a king?” Arthur wondered.
Leo answered, “A hero. A king fights for his nation, but a hero, a hero fights for everyone.”
“Your wisdom is astounding, young man,” Atlanna noted. “Or should I say turtle?”
Mikey called, “Either way is fine, your highness.”
Arthur understood and walked towards the waterfall while everyone watched. He stopped and looked back to see his mother, his wife, and all of his friends.
Leo told him, “I wish you nothing but the best of luck, Arthur.”
Everyone smiled and nodded, wishing him good luck as well. Leo held out his arm, which Arthur grabbed, showing the two had developed a great friendship. Arthur nodded back and looked at what lay ahead in front of him. He went through the waterfall and dived down to find the trident.
Atlanna said, “Good luck Arthur. We all have faith in you.”
Arthur swam underwater and searched through the seaweed and ruins for a while until he saw something shiny in front of him. He swam forward and saw King Atlan’s trident, holding still in the hands of a deceased King Atlan. However, Arthur sensed something big was approaching behind him, rumbling from the stoned ruins. He turned around and looked up to see giant tentacles coming from the Atlantean guardian known as the Karathen.
It telepathically stated, “I have guarded the trident against false kings since the beginning. And for a thousand years, I have seen the greatest champions try and fail.” Arthur looked to the left and saw thousands of skeletons, Atlanteans who failed to take the trident from the Karathen. “But never have I sensed one as unworthy as you. You dare come here with your tainted mongrel blood to claim Atlantis' greatest treasure?”
Arthur charged right after the giant creature, but he dealt damage from the tentacles of the Atlantean monster guardian, sending him crashing into the stones.
“So be it, half-breed.”
Arthur swam upwards and got hit again by the tentacles, but it didn't stop him from reaching towards the trident. However, one of Karathen’s tentacles blocked him and knocked him back down. While the tentacles surrounded him, Arthur knelt down to try to regain focus, but he remained strong though, knowing that if he fails, his wife, mother, and friends will be trapped here while the others fight a war without help.
“You thought yourself worthy? You thought yourself a king? You dishonor this place with your presence?”
While one of Karathen’s tentacles was ready to deliver the final blow, Arthur said, “Stop.” He wisely used his telepathic powers to stop the creature. “You're right. I am a half-breed mongrel. But I did not come here because I thought I was worthy. I know I'm not.”
“You understand me?”
“I do,” Arthur confirmed.
“No mortal has conversed with me since King Atlan. Who are you?”
“My name is Arthur Curry. Beaten by my own brother and took the throne again while I was lost. A nobody. I came because I had no choice. I came to save my home and the people that I love. I came because the trident is their only hope.”
“You would rather help people you don't know and your companions than being a king?”
“I would. Even if I'm unworthy, I just need it to get the people that I care so much home. And if that's not good enough,” Arthur stood up and stared at the creature with fearlessness in his eyes, “Then screw you.”
The Karathen moved aside as Arthur approached the trident. He placed his hand on it and in a few moments, he felt its energy and power running through his body. With Atlan’s spirit by his side, his eyes started to glow gold and his aquatic powers increased, heightened than ever before.
Back in the caverns, Mera, Atlanna, and Leo’s team sensed something from the waterfall and it was Arthur who emerged victorious with Atlan’s trident in his hand and a brand new suit.
“The one true king,” Atlanna said.
Leo smirked, “I knew he'd do it.”
Arthur once more became Aquaman and was ready for battle against his brother’s Atlantean army.