There is a virtual world parallel with ours: Lyoko. Created by Franz Hopper, data-processing genius and former teacher with Kadic College, Lyoko is composed of 4 territories: ice-barrier, the forest, the desert and the mountain. Each territory has turns, data bases which excavate the ground networks with research information and energy.
With the origin conceived like a numerical paradise, Lyoko is threatened today: XANA, the supercomputer which controls the digital world was infected by a virus and took its independence. It seeks today to destroy our world.
For that, it infects turns with the four corners of Lyoko.
Aelita, only the humanoid virtual which lives on Lyoko, resists to him. Until now, it was alone, but it finally found of the assistance:
On Earth, a band of four schoolboys knows the existence of Lyoko and the threat of XANA which threatens our world. They are Yumi, Ulrich, Odd and Jeremie.
They share a double life in the greatest secrecy: schoolboys like the others during the hours of course… and savers of world the remainder of time. They must maintain their secrecy bus if the authorities had suddenly learned the threat which XANA represents, Lyoko would be immediately destroyed and Aelita disappears.
For our heroes, it is not question. Between them and Aelita, it is a great history of friendship, and account equips it on work with Jeremie to be able to materialize the young person humanoid.
Our four friends found a "door" towards the virtual world: an old unused factory. They must go there in order to go on Lyoko to fight for our world. It is the only solution to counter the attacks of XANA.
Jeremy never goes on Lyoko: it is charged to virtualize his friends. He can carry out this operation thanks to scanners and a super computer in the room of the laboratory. It also takes care on them and each time guides them that they are on Lyoko.
Will Ulrich, Yumi, Odd and Jeremie manage to save the Earth, Lyoko like Aelita? Will they be able to decontaminate XANA without risking the life of their friend?