Code Lyoko - Season 3 - Eps 8: Temporary Insanity
Before leaving Sector 5, Odd and Ulrich are hit by a weird red beam from a pair of Mantas. They both eventually begin to act strange in the real world during a school play. They start seeing their environment, people as enemies, and fight as if they were still on Lyoko. They are branded as insane and hospitalized while Jeremie tries to figure out what happened. After finding the cause and devising a cure, Jeremie has Yumi and Aelita break them out of the hospital. Meanwhile, Xana uses their handicap to mount an attack on Lyoko's core. Yumi heads to protect the core, as Aelita tries to help the boys who instead now see the real world while on Lyoko.
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)