Code Lyoko (2003) : 2x12

After a Xana attack, Jeremie insists on a return trip, regardless of the fact that Xana didn't even cause any damage. When questioned, he gets defensive and angry, insisting that it's necessary. Further questioning on the matter leads to the same result. After the next return trip, Jeremie is found unconscious in his room. Yumi and Ulrich go searching through Jeremie's room to see what they can find about Jeremie's problem. Upon decoding a video diary that is stored on his computer, they learn that he had been using the return trips to increase his own intelligence. When he's about to be taken to the hospital, Xana attacks, possessing the ambulance and driving it towards the river with Yumi with him. Now the others have to save Jeremie and deactivate the tower without Jeremie's help.