In Lyoko's Ice sector, an activated tower is being guarded by a pair of Tarantulas. On Earth, a police transport is carrying a convict. An electrified fence on the side of the road releases one of XANA's ghosts. It enters the passing transport and possesses the criminal, Peter Duncan. He slumps down and the guard tells the driver to pull over so he can check on him. With superhuman strength, Duncan grabbs the guard and runs him through a window. Then, he attacks the driver and runs off into the woods. At Kadic, Yumi tells her friends that a local criminal, Peter Duncan, overpowered two guards and escaped. What disturbs her most is that the guards spoke of a "supernatural force", possibly XANA. Jeremie tells her that there are no activated towers. Aelita seems to get a headache and falters. The bell then rings, directing everyone to class. Meanwhile, Peter Duncan approaches a nuclear power plant with superspeed. Then, he falls to the ground in pain. In Mrs. Meyer's class, Aelita is having trouble doing her division test. Then, Peter Duncan and Aelita collapse simultaneously and go unconscious. Everyone begins to panic.
Aelita is taken by ambulance to the local hospital. Her heart rate is slowing down. The doctors use a defibrilator, but her lifeline still goes flat. Suddenly, her heart rate unexpectedly rises. In the woods, Peter Duncan gets up and heads for the power plant. The doctor goes to Aelita's friends, telling them that Aelita is going to be okay. He allows them to visit her. While visiting Aelita, Jeremie checks his superscan and still detects no activated towers, but he suspects it's giving faulty results. Jeremie, Odd, and Ulrich leave to go to the Factory while Yumi stays behind to keep Aelita company. Meanwhile, a truck leaves the power plant, carrying nuclear material. Peter Duncan jumps out in front of the truck, causing the driver to hit the brakes, but it seems too late as the truck is about to hit him. Duncan then ghosts through the truck, resolidifying behind it. He electrocutes the keypad and gets the correct number: 123456. The back door opens up and Duncan overpowers the two guards in the back, taking off with a uranium rod.
At the Factory, Jeremie virtualizes Odd and Ulrich into the Ice sector. They find the activated tower, despite the fact that the superscan isn't working. Suddenly, Jeremie's computer screen goes blank. Ulrich and Odd are now out of communication with him. At the hospital, Yumi is telling Aelita a story when she goes into cardiac arrest again. In the woods, Peter Duncan collapses, dropping the uranium rod. Jeremie takes the elevator to the Supercomputer Room to see what's wrong. On Lyoko, Odd and Ulrich shoot at themselves to devirtualize, but they don't return to Earth. In the distance, the land starts disappearing in a wave, leaving behind only the Digital Void. Odd and Ulrich take off on their vehicles, hoping to out run the wave. As the wave passes through, it even makes the activated tower disappear. Team Lyoko's vehicles disappear and they start falling into the Digital Void. At the last minute, Jeremie reactivates the Supercomputer. In Lyoko, the land reappears, breaking Odd and Ulrich's fall. At the hospital, Aelita's heart rate goes back up and in the woods, Peter Duncan gets up again. Jeremie discovers that the supercomputer's nuclear power source is running out, which is why his screen cut out and why the land in Lyoko started disappearing.
After bringing back Odd and Ulrich, Jeremie tells his friends that the supercomputer's power source is running out. If Lyoko shuts down, both Aelita and XANA will die. Unfortunately, he doesn't know where he can get nuclear material. He walks out into the Waiting Room and is abducted by Peter Duncan, who takes him to the Factory. Later on, Ulrich gets a call from Jeremie as Aelita goes into cardiac arrest again. Jeremie tells Ulrich that he has the uranium rod he needs to recharge the supercomputer. Unfortunately, once he recharges it, Peter Duncan, who is lying unconscious next to him, will get up and try to kill him. Jeremie then tells Ulrich to take Aelita with him to the Factory. Minutes later, the doctors enter Aelita's room, only to discover that she and her friends are gone. Meanwhile, Jeremie takes out the depleted rod of uranium and replaces it with the stolen uranium rod, recharging the supercomputer. He immediately runs to the elevator and the doors close before Duncan can get in. When he reaches the Lab, he finds out that the others are waiting for him in the Scanner Room. Aelita is there with them, better than ever. Ulrich goes up to the Lab as the others go into Lyoko. When they arrive, they are confronted by a group of Roachsters and quickly destroy them. Jeremie materializes their vehicles and they take off toward the activated tower. At the tower, they run into two Tarantulas and Yumi and Aelita fly off to the right. A Tarantula leaves it's position and pursues them. In the lab, Peter Duncan teleports in and Ulrich fights him. However, he knocks out Ulrich cold and turns his attention to Jeremie. On Lyoko, the Tarantula pursuing the girls shoots down the Overwing while the other fires at Odd, who is circling around the tower. Yumi destroys the Tarantula chasing her and the girls run back to the Tower. The lone Tarantula defeats Yumi and Odd, but Aelita uses Creativity, making a hole below the Tarantula. The Tarantula falls to its death as Aelita runs into the Tower. She deactivates the tower, as Jeremie is being held against a wall, being electrocuted by Peter Duncan.
The next day, Yumi reads from the newspaper, stating that Peter Duncan was found unconscious in front of the police station. It was them who dropped him off. Odd says one day, they will reap the benefits of saving the world. Even getting a zero on his division test won't spoil his optimism.
This episode contains examples of:
- Can't Live Without You: Besides his own self-preservation, XANA needs Aelita alive for his grand plan to work, hence why he's going to extreme measures to get the uranium core. The frantic nature of XANA is due to the supercomputer losing power, which also affects Aelita.
- Demonic Possession: Becoming a bit of a trend, eh XANA? This time it's a convict called Peter Duncan, which XANA uses to hijack a uranium truck. This is needed as the supercomputer is low on juice, and keeps shutting down, and more pertinently to Jeremie and XANA, killing Aelita.
- Drowning My Sorrows: Jeremie, in his temporary Heroic BSoD:Jeremie: (depressed) I'm going to get something to drink.
- Enemy Mine: XANA doesn't want himself to die, which is exactly what would happen if the supercomputer is turned off. XANA calls upon the help of Peter Duncan to steal the Uranium battery, who he then has kidnaps Jeremie to force him to change it. Once that's done, he starts trying to kill them as per usual.
- Formula-Breaking Episode: The second episode when XANA is largely not attacking the gang as he's more concerned about the supercomputer's battery going out and killing him.
- Have You Tried Rebooting?: Jeremie does this to the super-computer when it acts up, which causes issues for Ulrich and Odd, who very nearly fall into the digital sea.
- Intangibility: XANA displays this when he possesses Peter Duncan.
- Orphaned Punchline: While it leads to Mood Whiplash a couple of seconds later, Yumi gives one in the form of a funny story:Yumi: Wait, the funniest part is, Hiroki says to my father, “Papa, when I grow up, I’m gonna look like you, but with muscles!”
- The Password Is Always "Swordfish": The password to the uranium transport is....123456. note
