Code Lyoko - Season 1 - Eps 26: False Start
Aelita is materialized, but unfortunately, Xana implanted a virus inside of Aelita, so if Xana dies, so does Aelita. Then Xana decides to attack with bringing his own monsters to Earth. Ulrich and Yumi fight off the monsters, while Odd goes to Lyoko with Aelita. Odd eventually get materialized himself, but luckily, Ulrich and Yumi reach the factory, and fight off the last Hornet, attacking Aelita. She deactivates the Tower, and on the second run, the gang is talking with Aelita, about finding an anti-virus, but Aelita can still be materialized for small visits. So they look ahead to the future, and the episode ends.
About Code Lyoko

Title: Code Lyoko
First Air Date: 2003-09-03
Last Air Date: 2007-11-10
Status: Ended
Rating: 7.463/10 (from 81 votes)
Language: FR
Seasons: 5
Total Episodes: 95
Network: France 3
Genres: Sci-Fi & Fantasy, Animation, Comedy, Action & Adventure
Production Companies: MoonScoop, Antefilms Production
Synopsis
Four children travel to the virtual world of Lyoko to battle against a sentient artificial intelligence named XANA, with a virtual human called Aelita.
Cast

Raphaëlle Lubansu
Jeremie Belpois / Odd della Robbia (voice)

Géraldine Frippiat
Yumi Ishiyama (voice)

Marie-Line Landerwijn
Ulrich Stern (voice)

Sophie Landresse
Aelita Schaeffer (voice)

Mathieu Moreau
William Dunbar (voice)

Carole Baillien
Sissi Delmas (voice)