Vertigo is the eighteenth episode of Season 2 and the forty-fourth episode of Code Lyoko.


After a trip to Sector Five, Jeremie believes he has the data necessary to cure Aelita's virus. While Jeremie and Aelita work on the cure, Ulrich, Yumi, and Odd attend a rock climbing contest in the gymnasium. It is seen that despite Ulrich's hesitation, Odd still convinces him to go to the gym.

The contest starts with Herb versus Odd; Odd is the winner. William later challenges Ulrich despite his obvious reluctance. Not wanting to be humiliated in front of his friends, especially Yumi, Ulrich accepts the challenge. Just as his friends push him to keep going, Ulrich gets dizzy and fall afterwards, which makes Yumi realizes that he must have vertigo; a symptom that makes the patients feel the world or them-self is spinning. Ulrich runs away with embarrassment.

Meanwhile, Jeremie finds an anti-virus program and gives it to Aelita. Despite some problems with the application, it seems to work when Aelita remains safely. However, a bug in the program causes her to turn invisible right after Jeremie announces the good news to Yumi and Odd.

Back to Ulrich's escape from the gymnasium, Yumi and Odd find him sitting and sulking in the woods. They try to cheer him up with the news from Jeremie, but the conversation is interrupted by a possessed pack of wolves, which are from X.A.N.A.'s latest attack. The three run away with horror and face a rock cliff. While Yumi and Odd climb up successfully, Ulrich, once again, faces his vertigo but still manages to reach the top thanks to Yumi. Sooner than expected, a wolf appears in front of their faces three seconds later. The wolf pushes Ulrich off and makes him fall. He then discovers that the wolves are just illusions and announces it to Odd and Yumi. However, after getting rid of the illusions, some of the wolves are still alive.

After they receive a phone call from Yumi, Aelita insists that Jeremie virtualizes her to the Ice Sector to deactivate the tower. When she arrives, it occurs that the mentioned error in the anti-virus program blocks Aelita from entering any tower on Lyoko, resulting her inabillity to prevent 's X.A.N.A.'s attack. Aelita later faces the Scyphozoa and easily freezes the creature.

After hearing Jeremie's request for Aelita's aid, Ulrich orders Yumi and Odd to help Aelita while he fights the wolves by himself. After tries kicking them with a stick, Ulrich runs toward the city to seek for help. He contacts Jeremie and gets a sudden attack from the back by a wolf, which is seen by Jeremie through his computer screens.

Meanwhile, Yumi and Odd are transferred to Lyoko and look for Aelita, but are blocked by a Megatank. Yumi gets devirtualized while Odd manages to defeat the monster. Aelita encounters a few Hornets and runs away. Accidentally, she returns to the spot where she freezed the Scyphozoa. The creature unleashes itself in front of a horrified Aelita, and the Hornets reach her from the back. While Aelita is literally hung up, Odd manages to reach her spot, and sneaks pass the Hornets by swimming under water. He frees Aelita from the Scyphozoa by using his Laser Arrows.

Jeremie, still working on his anti-virus program with Yumi along his side, and both of them witness Ulrich collapsing inside the factory. Yumi attempts to help Ulrich, but the anti-virus program is stopped at the same time, so Jeremie stops her. Eventually, Aelita deactivates the tower and Jeremie launches a return to the past to heal Ulrich's injuries and send the wolves back to where they came from.

Back to the day earlier, while William mocks Ulrich for being dizzy, Ulrich revenges by announcing William's fear of spiders (which he discovered from Sissi) and calls him Spider-Man before leaving with his friends.


  • The original French name for this episode is Vertige.
  • Chronologically, this episode takes place after the events of both Temptation and A Bad Turn. However, it aired before either.
  • At the beginning of the episode when the group is in Sector Five, it is revealed that Mantas can deploy flying mines.
  • It is also revealed that William is afraid of spiders.
  • At the very end of the episode, Odd makes a reference to the Fantastic Four when he compares Aelita's invisibility to Sue.
  • Yumi says "Konnichiwa" in her cell phone's voice mail message when she would have actually said "moshi moshi" in the Japanese language. The Japanese use that phrase to answer the phone.