The series centers on a group of teenagers who travel to the virtual world of Lyoko to battle against a malignant artificial intelligence known as XANA. The scenes in the real world employ traditional animation with hand-painted backgrounds, while the scenes in Lyoko are presented in 3D CGI animation. The series began its first, 97-episode run on France's France 3, and ended on 10 November 2007. It started airing in the United States on 19 April 2004 on Cartoon Network.