Code Lyoko - Season 1 Episode 22 -

After many X.A.N.A. attacks in a row, Ulrich starts to get tired of fighting. He also questions his relationship with Yumi and if she feels the same way about him. X.A.N.A. activates a tower without disturbing Earth, Jeremie forces Ulrich, Odd, and Yumi all to go to Lyoko to deactivate the tower. After being virtualized, a virus infection occurs on Lyoko because X.A.N.A. sabotages the Devirtualization Program, meaning if the group is devirtualized, they will permanently perish.