Lyoko Minus One

Plot:

Yumi, while on a field trip with hr 10th grade class, finds herself up against the students, teachers, and even the bus driver, all of whom XANA has possessed. At the same time, XANA had decided that simply attacking the core to get rid of Lyoko would be a hassle, and plans to get rid of it through an alternate means: destroying the sectors one at a time. And so, he uses the Scyphozoa to possess Aelita and enter a new code, XANA, into the forest sector's way tower, which in turn deleted the entire forest. In a side-story, Jeremie, Odd and Hervé compete for class ...