Who sank Atlantis? Mera, the beautiful Atlantean assassin trained in the Bermuda Triangle, follows a trail of death and deceit to the one man who knows the ugly truth. But what does he want in return for his secrets – and how does it all tie into Mera's own dark past?
Four years ago, Mera was training on Xebel to assassinate Aquaman.
In the present, Mera is buying food for her dog. She asks the manager for help, and the manager begins to behave inappropiately with Mera. When the manager grabs her waist, Mera breaks his arm. Two security guards try to arrest her, but Mera defends her actions, saying that the manager was trying to hit on her. The guards ignore her, so Mera uses her water powers to defend herself.
The police comes to the scene, and the cops try to arrest her, but they recieve a call about a man named Ryan Slayter causing trouble. Hearing about the situation about Slayter, Mera willingly surrenders, asking the cops to go where they need to go.
Mera is taken to the police car, and the officers drive to Slayter's home, where Slayter is holding her daughter at gunpoint. Watching the situation unfold, Mera breaks her handcuffs and gets out of the car. Mera tries to solve the problem by herself, but Slayter underestimates her. Mera uses her water powers to drain the water out of Slayer's body, causing him to dehydrate. When Slayter is about to die, his daughter begs Mera to stop. Mera is confused, saying that Slayter killed her mother, but the girl replies that he is still her father. Mera restore the man's back to normal and leaves, ignoring the police.
As she stands on rock on the shore, Mera remembers her time on Xebel. She asked her father why are they trying to kill Aquaman since he doesn't know the Xebel exist and he doesn't want the throne of Atlantis. Mera begged her father to stop, saying that Aquaman is noble. However, her father replied that Mera was a traitor, and traitors must die just like Aquaman. Mera says he will have to kill her, and her father remarks she will be alone like Aquaman.
As Mera finishes remembering her past, she is met by Jennifer, a worker at the store Mera visited earlier. Jennifer was being harassed by the manager before Mera arrived. She gives Mera a bag full of dog food. When Mera asks why, Jennifer replies she wants Mera to know that humans are not all bad, and Mera agrees.
Mera arrives home and feeds the dog, then Aquaman arrives and Mera says they should talk. Aquaman says that they can talk on the way to Stephen Shin's house, because they'll ask him who sank Atlantis.