The episode begins with Bendo walking through a grimy sewer, to fix a problem in Zindiga's plumbing system. He then suddenly stops, and sees a frightening vision of unknown Bakugan destroying Zindiga and Xia. Phos asks him what is wrong, and Bendo responds that it was just a sudden spazz-out. They fix the problem, and return up, to see a poster of the next battling tournament between Zindiga and Xia's champions. He sees that Slax and Saber are entering, so he decided to enter as well.
On his way to the arena to sign-up, he spies a group of kids looking at a glowing device on the ground. It looked like a cell-phone from Earth, but with mainy different switches and buttons on it. Bendo tells the kids it could be dangerous, and picks it up. The device shocks him, and knocks him out. While he is knocked out, he sees the Hearts unlocking the seal that keeps Mercuritron imprisoned. When he wakes up, he finds himself on the ground, alone. He gets up, and notices that the device is no longer glowing. He cautiously picks it up, and puts it in his pocket. Phos asks him what happened when he was out. Bendo lied and said he saw nothing. Phos begins to realize Bendo is keeping secrets from him.
When they sign up, they meet their opponent, a boy with unusual eyes. Phos asks Bendo what's with him, but even Bendo didn't know what was with him. When the battle starts, the kid throws out a Bakugan Bendo and Phos have never seen before. The boy claims it is a "Terozon", a Bakugan with unimaginable power. Phos is thrown out. He seems to gain the upper hand at first, until he realizes the Terozon is faking. The Terozon then releases a volley of attacks, and Phos is beaten down. Bendo summons Nano Drones Hydricer and Terrordrill to distract the Terozon. Phos wins round 1.
In round 2, Phos is doing well, until Bendo sees something very disturbing on the Terozon. On its shoulder, clearly showing, was the mark of Mercuritron. Bendo gasped, and warned Phos of his discovery. Phos begins to battle with more strength, and the Terozon is knocked out. Bendo wins the battle, but is more concerned about the device and the Terozon.
Bendo returns to his lab, and examines the small device. It is shown to have technology beyond him, which Bendo is stunned about. Slax enters the room with Raze Ripper and asks what he is doing. Bendo shows him the device, and Slax's eyes widen when he sees it. Slax explains that it is used to enslave someone, and show Mercuritron's plan to them, so that they can carry it out. Bendo then says that he saw the Hearts unlocking the seal that Mercuritron was trapped in. Slax wonders why it didn't work on Bendo. The episode ends with them discussing the matter.