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

Plot

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 realize 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 weakens her and ultimately 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, thanks to Jeremie's tip, 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 X.A.N.A.'s latest attack: a pack of possessed wolves. 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's encouragement. However, one of the wolves manages to reach the tof and pushes Ulrich off. He falls on top of another wolf, which vanishes on contact. Realizing that the wolves are just illusions, Ulrich announces it to Odd and Yumi. However, after getting rid of the illusions, they realize that three of the wolves are indeed real animals.

After they receive a phone call from Yumi, Aelita insists that Jeremie virtualizes her to the Ice Sector to deactivate the tower in the ice cave. When she arrives, it turns out that the mentioned error in the anti-virus program blocks Aelita from entering any tower on Lyoko as the towers do not recognize her, resulting in her inability to prevent X.A.N.A.'s attack. Then the Scyphozoa arrives to capture Aelita but she immediately freezes the creature with ease in the ice block and tries to leave the cave.

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 flees through the city to seek shelter in the Factory. He manages to reach the bridge and contacts Jeremie before one wolf tackles him to the ground, 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, on her way to the exit, encounters two Hornets and runs back to the cave. Accidentally, she returns to the spot where she froze the Scyphozoa. The creature heats up it's tentacles to shatter the ice and frees itself in front of a horrified Aelita, and the Hornets block her way out. As the Scyphozoa begins stealing Aelita's memory, Odd manages to reach her spot and sneaks past the Hornets by swimming underwater. He frees Aelita from the Scyphozoa by using his Laser Arrows.

Jeremie, still working on deleting the anti-virus program with Yumi along his side, witnesses Ulrich try to lower himself to the elevator with the ropes, but he slips and falls unconscious, leaving him helpless as the wolves close in on him. Yumi attempts to help Ulrich, but the anti-virus program is stopped and deleted at the same time, so Jeremie stops her. Just as the wolves are ready to maul Ulrich to death, Aelita enters and deactivates the tower, causing the wolves to fall unconscious. 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 gets revenge by announcing William's fear of spiders (which he discovered from Sissi) and calls him Spider-Man before leaving with his friends, all while Odd compares Aelita's invisibility to Sue from the Fantastic Four.

Trivia

• The original French name for this episode is Vertige.
• The idea for this episode stemmed from the writers wanting to base one around a personal issue with Ulrich. They ultimately liked vertigo and partially chose it since they couldn't remember anything from Season 1 that would contradict it; "he never climbed up a tree or anything."^[1] Sophie Decroisette also confirmed that it doesn't affect him on Lyoko.
• 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. Ironically, in the fourth season. William, under XANA's control. Would ride a spider in Dog Day Afternoon
• The tower activated in this episode might be the same tower X.A.N.A. activated in Satellite.
• Wiliam is always nicknamed Spider-Man, which is refered to Marvel Comics's Spider-Man.

Errors

• At the beginning of this episode when Jeremie is trying to find to key the timer shows a minute and eight seconds but when the key is activated by Odd the timer shows a minute and sixteen seconds.
• When Jeremie tries to call Yumi in the sewers, she says "Konnichiwa" in her cell phone's voicemail message when she would have actually said "Moshi moshi" in the Japanese language. The Japanese use that phrase to answer the phone.
• The sweater which Aelita wears as her sporting clothes is gray instead of a dark pink.

Gallery

Other

Concept art of the wolves.

References