In a cavern in Santa Prisca, Black Beetle and Deathstroke enter from opposite sides and nod to each other. Their respective groups, The Reach and The Light, enter the cavern. Vandal and the Ambassador greet each other, and Black Beetle insists that everyone remove their masks. Black Manta reluctantly does so, while the undercover Artemis worries to Aqualad that they're in over their heads.
Vandal and R'as Al Ghul inform the Ambassador that the rest of The Light is busy handling damage control after the recent revelations about The Reach's hidden fleet. The Ambassador demands to know how Young Justice gained access to the Bialyan scarab temple. When Aqualad steps forward to explain, Black Beetle tells him to remain silent. Vandal points out that Aqualad has sacrificed as much as anyone and is entitled to a voice there. Aqualad points out that The Light couldn't have known the significance of the temple and that The Reach kept the information from them. The Scientist complains about how the Ambassador didn't follower her advice, but realizes that she's said too much.
The Ambassador refuses to discuss it further but The Light points out that The Reach has failed over and over again. In response, the Ambassador informs them that Blue and Green Beetle will soon be back under Reach control and that they have summoned Black Beetle from the key chamber on Warworld to kill them and put their scarabs in new host bodies. The Light are only the favored agents of The Reach. Black Manta refuses to serve as a slave and Black Beetle smashes him aside. Deathstroke and Artemis attack Black Beetle and The Reach's soldiers open fire. A blast knocks Artemis back into Ra's, and he notices the charm around her neck.
The fight continues until Aqualad steps in, saying that they have to stop the fighting among them and battle their true enemy, the Justice League and their sidekicks. The Ambassador agrees and orders an angry Black Beetle to stand down. The villain reluctantly does so and Aqualad asks if the heroes on trial will return from Rimbor. Vandal assures everyone that he has guaranteed their convictions and the Green Lanterns aren't allowed because of the Reach treaty. The Ambassador figures that they can easily rebuild the public's trust in The Reach. As he talks, Ra's walks to Artemis and removes the charm necklace. The spell fades, revealing her true face.
When the Ambassador points out that Aqualad was the one that supposedly killed Artemis, they realize that he has been working undercover. Black Beetle prepares to kill them both but Black Manta intervenes. Deathstroke shoots Aqualad and Artemis, saying that The Light takes care of its own. As he lies dying, Aqualad tells his father that he's worn. He triggers a remote playing a hologram announcing that The Light has been manipulating The Reach. First they sent the heroes to Rimbor, attracting The Reach's attention. Aqualad continues, explaining how The Light secretly kept the meta-teens out of The Reach's hand, neutralized the tainted energy drink, and gave Young Justice access to the scarab temple. The recording ends and Vandal concedes that Aqualad has disrupted his plans.
The Ambassador flies into a fury, reminding them that The Reach controls Warworld. Vandal points out that he has the crystal key. When Vandal says that, Aqualad and Artemis stand up. "Deathstroke" levitates a sword to Vandal's throat and reveals that she's actually Miss Martian in disguise. The rest of Young Justice enters the cavern and Vandal admits that they've done well... but The Light always has contingencies.
The Brain's housing glows and the cavern entrances come down. The Light's ninjas drop in from the roof and Vandal tells them to dispose of Young Justice. Blue Beetle, Beast Boy, and Lagoon Boy, disguised as three of the ninja, attack the others and Young Justice takes up the attack against both sides. Impulse, Wonder Girl, and Robin, also disguised as ninja, help their comrades.
Vandal considers that they've underestimated the younger heroes and then summons Klarion. He sends a fire serpent to attack Miss Martian and then teleports away with Vandal. Ra's advises everyone to stop fighting since Young Justice has no jurisdiction there. Disgusted, Black Beetle stabs Ra's through the chest and his bodyguard, Ubu, runs to his master's side. He takes Ra's away through the ceiling entrance, knocking Artemis aside when she tries to stop him. Kid Flash runs to Artemis' side to help her.
Black Manta confronts his son and asks how he could have betrayed him. Aqualad admits that he has seen his father's noble side but had no choice as long as Black Manta wastes his gifts on villainy. Disgusted, Black Manta attacks his son.
Lagoon Boy attacks the fire serpent and destroys it from within. Miss Martian thanks him and they look at each other for a moment, and then return to the battle.
Kid Flash and Impulse join forces and Kid Flash suggests that Impulse carry on the family tradition when he retires. Impulse disarms The Brain but is knocked down when Mallah throws Beast Boy across the room. Meanwhile, Black Manta insists that he has to be ruthless and vows to beat the lesson into Aqualad. Aqualad finally knocks his father unconscious and hopes that his ruthlessness made him proud.
As the Ambassador and the Scientist try to flee the chamber, Blue Beetle pins them both to the wall. When they call to Black Beetle for help, he tells them that under The Reach's Acquisition Code, he declares the Ambassador unfit and takes the Scientist with him, escaping through the ceiling. The battle ends and Aqualad tells Nightwing that several of the villains escaped. The other heroes point out that Aqualad has successfully crippled both groups. Artemis has the entire thing recorded on the necklace so that they can make The Light's confession public and clear the League.
On Warworld, Klarion teleports away The Reach guards. Vandal emerges and attacks the League members on duty.
At the Watchtower, Nightwing returns command of the team back to Aqualad. They're interrupted when vandal tosses the defeated League members through a portal and then departs aboard Warworld, heading off into deep space.
At the UN, Captain Atom presents the evidence showing that The Reach are conquerors. The UN officially rescinds The Reach's invitation to stay on Earth. Black Beetle and the Scientist watch the news broadcasts and realize that the Green Lantern Corps will soon be on its way. They realize the summit was a ploy to lure them away from the Warworld. To cover the evidence of their activities from the Guardians of Oa, Black Beetle vows to destroy Earth to cover their tracks.