Episode Title:
Vertigo.
Episode Description:
After a trip to Sector 5, Jeremy believes he has the data necessary to cure Aelita's virus. While the two work on the cure, Odd, Ulrich, and Yumi go to a rock climbing contest. Odd races against Herve, who is no match for Odd. William then goads Ulrich into racing, despite his obvious reluctance. During the race, Ulrich gets dizzy and falls. Yumi realizes that he must have vertigo. Ulrich, embarrassed, runs off. Meanwhile, Jeremy finds the antivirus software and gives it to Aelita. Despite some problem with the application, it seems to work. However, this does not last; an error in the anti-virus causes her to turn invisible. On top of that, she cannot enter the towers on Lyoko, making it impossible for her to stop X.A.N.A.'s latest attack, which is a possessed pack of wolves targeting Odd, Ulrich, and Yumi.
