Episode Title:
Lyoko Minus One.
Episode Description:
During a field trip with the rest of her 10th grade class, Yumi finds herself facing off against the students, teachers, and bus driver, all of whom X.A.N.A. has possessed. At the same time, X.A.N.A. plans to get rid of Lyoko through alternate means: destroying each sector one at a time. To this end, he uses the Scyphozoa to possess Aelita and enter Code: X.A.N.A. into the way tower, wiping out the Forest Sector completely. Jeremy then realizes that with the four main sectors gone, they will not be able to go to Sector 5.
