Air Date: April 19th, 2004
A group of students uncovers a parallel universe threatened by a virus.
Season 2 - Episode 18 : Vertigo Oct 12, 2005
Ulrich is afraid of heights, but he's never admitted it to his friends.
Season 2 - Episode 15 : Ultimatum Oct 7, 2005
XANA possesses the Headmaster and Aelita deactivates the tower.