|Air date||January 20, 2014|
|Written by||Josep Maria Roca Peña|
The Great Battle
Anthea Schaeffer and her daughter Aelita are rebuilding and remodeling the Hermitage with the help of workers repairing what needs to be repaired, and meanwhile Lyoko-Warriors help when they can. Later, after taking classes, the Lyoko-Warriors are on the playground. Jeremy talk about something important, Anthea arrives and tells Aelita that should go to the center of the police because they will be interrogated (the authorities know that Anthea had disappeared and now she has returned). As they leave, Jeremy goes to the Factory.
While Aelita and Anthea go to police office of Boulogne-Billancourt, Odd, Ulrich, Yumi and Sissi are in the recreation room. Sissi is playing table football with Thomas Jolivet. Odd is surprised by the fact that Tania Grandjean is making as the instructor instead of Ulrich. Then tell him that the last time it had been decided that the monitor was a student at random, one per day and you do not necessarily have to be a single supervisor. Taelia sees them and is confident that they will have problems after the return of Anthea and Aelita's questioning.
Anthea signing some papers in the police center, and then Aelita talks about Men In Black. The police, when they hear about black men, said that this issue goes far and they shouldn't get into it. The police say they better back home, and Anthea and Aelita leave. Meanwhile, Ulrich receives a call of Jeremy telling you that he should go to the factory and go with those that are available. Ulrich tells him he'll go, and tells it to Odd and Yumi. Sissi finishes to play with her friend and she goes with them, just then they find Aelita, all go to the factory.
At the factory, Jeremy discovers one thing in one place there are three worlds: the real world, the Digital Sea and Virtual Limbo. So he does some explanations on paper drawings of the three worlds, representing a square as the Universe, a triangle as the Digital Sea and a circle as a Virtual Limbo. Odd says that if they need this, and says he'd rather be playing with his game console to attend a physics class Jeremy. Odd says he prefers Mrs. Hertz, because he can sleep. Jeremy tells Odd that if he wants, he can go back to Kadic. Odd stays.
While they are in the factory, Aelita and her mother are left to live in the renovated Hermitage. The two are talking about things, while Jeremy detects activity on Xanadu. Quickly call others to go to the factory. Meanwhile, in the arms factory in New York, some missiles are beginning to take off and fly over the sea to France. And at the factory, Jeremy tries to virtualize the Lyoko-Warriors, but some programs fail and Jeremy cannot virtualize. Jeremy says X.A.N.A. is doing something with the supercomputer, but hasn't activated any tower. Odd, Ulrich and Sissi go back to Kadic, and Aelita, Yumi and Jeremy stay in the Factory.
Aelita is working from Jeremy's laptop, and Jeremy from the supercomputer. Then Aelita finds something on her screen, and passes it to Jeremy. Turns out there's an encrypted message. Quickly call others while Jeremy tries to decrypt the message. Aelita and Jeremy start work until the others arrive. Everyone come to the factory, and the message is quite revealing: "It's time to step back, X.A.N.A. has almost reached its maximum power. There are few missiles that could destroy the factory, I have to act fast. I must stop X.A.N.A. I'm Franz Hopper".
All are surprised, least Sissi that asks, "Who is Franz Hopper?" and Aelita says: "My father". Sissi doesn't understand, and says she believed that Aelita was an orphan, and now first her mother appears and then her father. Aelita said that her father created the supercomputer and Lyoko, X.A.N.A. and everything related to it. Sissi says that now would be the best time to tell all to her father and the police, and Aelita and Jeremy say just now is the worst time to reveal all. Sissi agrees not to reveal anything, and the episode ends with all the Lyoko Team in the factory.