Episode Title:
Marabounta.
Episode Description:
After deciphering a part of Franz Hopper's diary, Jeremy gets an idea to make a monster that fights on the side of good. By combining techniques, he makes the Marabounta, a black sphere that can exponentially replicate itself endlessly and devour any monster it may encase. Though it works quite well to begin with, everything goes wrong when it senses Aelita's virus, which is linked to X.A.N.A.. After Odd attacks it to save her, the Marabounta goes haywire and threatens to devour all of Lyoko, so X.A.N.A. sends his monsters to help destroy the Marabounta in order to protect Aelita and her memories. The monsters leave the Lyoko Warriors without causing any trouble. In a side story, Ulrich follows Yumi to the pool because of his jealousy towards William who is also at the pool with her.