S04E01 — William Returns

Using the data that Franz Hopper gave them, Jeremie and Aelita succeed in recreating Lyoko, which now holds only Sector Five. Soon after, William is devirtualized, and seems perfectly normal. Sissi decides to make herself "editor-in-chief" of Kadic News, much to Milly and Tamiya's dismay. She soon barges into Aelita's room to interview her and is stopped by William. As soon as William makes Sissi, timay and milly leave,William kidnaps Aelita and takes her to Lyoko. William leads Aelita out of Sector Five and to what used to be The Desert Sector. His intent is revealed to throw Aelita into the Digital Sea. Odd manages to stop him, but William dives into the digital sea. Jeremie concludes that this is Xana's new strategy, and that they must be careful.