Code Lyoko - Season 4 - Eps 6: Maiden Voyage
The gang manages to convince Jeremy to let them test out the Skid. During this test, the navigation system bugs up, leaving the gang stranded in the digital sea. Jeremy runs to his room to fetch the backup programs, but forgets that it's Fire Safety Day and runs into several teachers, eventually having to scale the roof to get to his room. Meanwhile, the Skid stumbles upon another Lyoko and is attacked by two eel-like monsters. Jeremy is able to repair the navigation system and bring his friends home, after which he surmises that the replica of Lyoko is created from the portion of the Keys to Lyoko that X.A.N.A. has stolen from Aelita's subconscious in the second season finale, The Key. Jeremy wonders how he plans to use it.
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)