A student named Milly seeks the comfort of her teddy bear after being embarrassed and ostracized due to her young age by Sissi, the school's bully/diva. Milly believes that her teddy is the only one …

Odd decides to start a music band with his friends. But Jeremy can't play, so they try to hire a drummer. In the end, the best drummer they can find is Nicholas (Sissi's blond-haired crony). As the …

Ulrich and Jeremy are doing graffiti on a wall on campus while Kiwi wakes up Jim. When Jim passes Ulrich and Jeremy, Ulrich gets away, but Jeremy just stays there and gets I'm trouble and has to stay …

Sissi has found something very special and dear to Ulrich, his diary! Unfortunately the diary contains some information on X.A.N.A. and Lyoko. Sissi decides to use this as a means of blackmail to ge…

The day starts off when two girls are talking about Ulrich and then Sissi goes and interrupts and tells the girls that Ulrich is hiding his affections for her. Later, Odd, and Ulrich pull a prank on S…

Jeremie is working on the materialization program, and finally gets it. Jeremie wants to matierialize Aelita, but realizes that preparations need to be made. That night, Xana possesses two bulldozer…

This episode starts out as Yumi and Aelita are running inside Lyoko looking for the activated tower. Then Yumi suddenly disappears! She comes out of Lyoko exhausted, and looks just fine! Until Yumi Co…

When a director comes to town to film a movie, XANA posseses a plastic alien model in order to destroy Ulrich and the others.

When all the student's cell phone goes off in class, it starts Sissy on a petition to save her cell phone--but it's goes awry when Odd breaks into the school's office's locker to get his, Ulrich, & Yu…

Jeremie mysteriously loses contact with Aelita. The same day, a new student named Taelia (who looks alot like Aelita) arrives at school. Jeremie is convinced that Taelia is Aelita devirtualized, but …

Jeremie learns that he has to take a test. If he passes, he'll get transfered to a new school and nobody will be able to stop XANA. Speaking of which, XANA takes control of a pack of rats. The rats a…

Ulrich is fussing over a mysterious letter found slipped under his door one night... a love letter signed by Yumi! Meanwhile, XANA infects a hive of bees and is using it to attack our heroes. Ulrich…

The episode starts with Jeremie still trying to materalize Aelita. He calls the team to the factory to show them his latest development: a strand of her hair that he has materalized into a test tube.…

It's the anniversary of the day Jeremie and the others met Aelita. They begin planning a surprise for her, unaware that Sissi is spying. When Jeremie and Odd try to open the lab elevator, it won't w…

After seeing laughing gas in Science class, Team Lyoko has to see it again - working for Xana. While working for Sissy in a school production of Romeo and Juliet, Ulrich and Yumi are overcome by the …

After a quick game of soccer, Yumi heads home for the night, but Odd and Ulrich head in for dinner, and Jeremie is already there. He decides to check on Aelita, and Yumi ends up following him instead…

When learning about NanoDoctors, small robots being designed to cure dieases, Ulrich holds some gel that the NanoDoctors would live in. Od pranks him and pushes the gel into Ulrich's face, and some mi…

A new rock song Odd downloads sends him into a coma, and the same song is passed through the school. XANA's new beat is the cause, and he can broadcast it anywhere. The hospital is full to bursting …

Jeremie is now taking his ""Materalize Aelita!"" campaign to levels unknown - quite literally. He virtualizes himself, but there isn't enough memory in the system to complete the transfer, and Jeremi…

Both Herb & Jeremy are in a robot competition Herb with ""Iron Sissy"", and Jeremy with ""Kiwi 2."" Herb cheats by launching a gear from Sissy to destroy ""Kiwi 2."" Meanwhile, Xana's latest plan, u…

Xana decided to get rid of everyone by using the power of Gravity, and Yumi, Odd, and Jeremy went to the factory, but Ulrich had a soccer game, and his Dad was there, and as Odd said: If you're not fi…

Ulrich is getting tired of getting being rebooted so many times and waiting to find out if Yumi has feelings for him or not. He thinks these are his only troubles, but he is not counting on two thing…

Well, it starts off as Yumi wanting to have a party at her house. Of course, Odd jumps into action, and says that he has the Deejay problem all solved, they weren't going to listen to Sissy's music. B…

One day at school, Jeremy notices that Odd, Ulrich, and Yumi are missing. Meanwhile, Odd, Ulrich, and Yumi ARE at school with Jeremy! What's going on? Turns out that XANA (in the form of Jeremy) has t…

As Jeremy is perfecting his materialization program for Aelita, Yumi, Ulrich and Odd are making preparations for her arrival. But as success comes within their grasps, Jim's paranoia aggrivates the al…

Aelita is materialized, but unfortunately, Xana implanted a virus inside of Aelita, so if Xana dies, so does Aelita. Then Xana decides to attack with bringing his own monsters to Earth. Ulrich and Yum…

After discovering Aelita's link to the supercomputer and the inability to shut off the supercomputer that stems from it, Jeremie works hard to find new and better ways to fight Xana. To that end, he d…

While Aelita adjusts to her new life on Earth, Jeremie and the others investigate the mysterious owner of the Hermitage, Franz Hopper, and his link to the supercomputer, Lyoko, and Xana. It is discove…

After discovering The Carthage Region, the group decides to explore it. Yumi is forced to opt out after her continued late-night trips to Lyoko draw the attention of her parents. While on The Carthage…

After taking another trip to The Carthage Region and returning to the school, Aelita talks to Jeremie about not being human, unaware that Sissi is recording their conversation. On top of that, the dat…

When Aelita's dreams and hallucinations become too disruptive to ignore, the group heads to the Hermitage to discover their source. There, Aelita finds a doll she inexplicably recognizes to be Mister …

It's Saint Valentine's Day and love is in the air. Ulrich forgets, so at last minute writes a poem for Yumi. However, when William presents Yumi with flowers, Ulrich gets jealous and reads the poem to…

When the school holds a concert in the gym, William accidentally drops a mixing board for the DJ contest. Odd offers to fix it, and tries to get Jeremie to help. Jeremie is busy, so Aelita offers her …

During a mission to The Carthage Region, the Scyphozoa attacks Yumi, stealing her human DNA, having her trapped on Lyoko. To make matters worse, it's picture day for her class and she will be suspende…

When Ulrich learns that Yumi might have to go back to Japan because her father lost his job, he can't accept losing her. After hearing the lottery numbers on the radio though, he gets an idea. Using a…

After deciphering a part of Franz Hopper's diary, Jeremie gets an idea to make a monster that fights on the side of good. By combining techniques, he makes the Marabounta, a sphere that can replicate …

When the supercomputer's uranium power source begins to fail, Xana is forced to possess a local criminal named Peter Duncan to replace it. The supercomputer's periodic shutdowns threaten not only Xana…

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. Furth…

Ulrich and William get into a fight over Yumi. When Xana activates a tower and materializes Krabbes, he attacks Yumi's house and destroys two scanners. While Ulrich is in detention, Yumi defends her …

When Xana possesses Kiwi, it turns the little dog into the carrier for a virulent virus that turns those it infects into zombies. To make matters worse, Aelita and Jeremie are stuck in the cafeteria a…

After Xana possesses the principal of the school and kidnaps Odd and Yumi, he gives Jeremie an ultimatum: deliver Aelita to the Scyphozoa or sacrifice Odd and Yumi. However, Jeremie and Aelita go to S…

After a malfunction and a little bug with the regular materialization program, Odd and Yumi are bugged up, ending up in each others' bodies. Even worse, their atoms start splitting after a while due t…

Xana creates a ghost called a polymorphic specter, that can change its shape or form at will and doesn't need to possess a host, then uses it to drive a wedge between the group by having it kiss peopl…

After a trip to the Carthage Region, Jeremie believes he has the data necessary to cure Aelita's virus. While the two work on the cure, Odd, Ulrich, and Yumi go to a rock climbing contest. Odd races a…

Jeremy is woken up to an alarm signal, with no activated towers, so he goes back to sleep. The next morning, while Jeremy and Aelita are investigating Jeremy's computer, Odd looks for his DVD of his m…

Aelita's visions become a problem once again, but not the same visions as before. This time, she has visions of her and Franz Hopper being chased by government agents. The visions come even when she's…

During the school physicals, Xana possesses the school nurse, Yolande, and has her kidnap Aelita. The rest of the group beats her to the factory, but has no way to get Aelita from the far more powerfu…

After reading about a dead man named Leon Corbe, who died during the construction of Kadic, Sissi decides to hold a séance to communicate with him. She manages to convince Ulrich to attend. During the…

Jeremie discovers five activated towers and gathers the group to take care of them. However, when they arrive at the factory, they find a man at the interface, deactivating the towers as if it were a …

During a short film made by Odd and starring Sissi, Sissi seems to be possessed by a ghost. She does not act as expected, however. Instead, she starts speaking in some strange language, focusing on Je…

It's nearing the end of the year and Jeremie's research has hit a dead end. After the group collects some data from The Carthage Region, he plans to use a tower to decipher Franz Hopper's diary. Befor…

After going through all of Franz Hopper's diary, Jeremie discovers the truth behind the supercomputer, at least to some extent. Hopper had used it quite extensively, to the point of repeating a single…

After another three-week vacation, the group is still looking for a way to fight X.A.N.A.. X.A.N.A., meanwhile, is trying to destroy Lyoko, preventing them from doing just that. He does so by targetin…

During a field trip with the rest of her 10th grade class, Yumi finds herself facing off against the students, teachers, and bus driver, all of whom Xana has possessed. At the same time, Xana plans to…

Xana attacks the Lyoko warriors by possessing a large amount of food. At the same time, he bugs up The Mountain Sector by rising the digital sea, but Odd and Aelita go to Sector 5 to stop him. Xana al…

When Xana hacks into a weapon's manufacturing computer network and leaves a paper trail pointing to Jeremie, government agents arrive at the school looking for him. Then, the whole gang arrive at the …

Aelita gets mad at Jeremie and she and Odd go into Lyoko without telling anybody, which causes problems. On lyoko, Xana creates a diversion to get everybody to deactivate the tower in The Mountain Sec…

Odd and Ulrich are talking in the shower room when a young boy, Johnny, asks to talk to Ulrich. It turns out that Johnny likes Yumi, and being jealous of that, Ulrich tells him to follow her around to…

After being rejected by Yumi, William makes it his mission to find out the secret she's hiding. Soon enough, he manages to follow Ulrich and Odd to the factory and learns about Lyoko and Xana. Meanwhi…

Before leaving Sector 5, Odd and Ulrich are hit by a weird red beam from a pair of Mantas. They both eventually begin to act strange in the real world during a school play. They start seeing their env…

When Xana sabotages the supercomputer, weird bugs begin cropping up in Lyoko. With its power rapidly draining, Jeremie needs to repair it before it becomes completely useless. However, he seems to for…

During a test to materialize Ulrich directly into Sector 5, his mind and body become separated, leaving Ulrich's body trapped on Lyoko and his spirit stuck on Earth. What's worse, Xana possesses Ulric…

When Odd complains that he doesn't have any cool powers on Lyoko like his friends, Jeremie designs him a teleportation power. It works, but ends up leaving duplicates of himself in the location he tel…

With Xana's attacks becoming more and more difficult to handle, the group contemplates adding another member to the team to make things easier. William is still the prime candidate, but Yumi still doe…

After William is initiated into the group, a series of events leaves only him and Aelita to defend Lyoko's core. During William's first mission to Lyoko, Xana uses the Scyphozoa to possess him, making…

Using the data that Franz Hopper gave them, Jeremie and Aelita succeed in recreating Lyoko, which now holds only Sector Five. Soon after, William is devirtualized, and seems perfectly normal. Sissi de…

In order to compensate for all of William, while under XANA's control, Jeremie sets to work designing new equipment for his friends and recreating Lyoko. In order to buy himself time to do this, he ac…

Jim's nephew, Chris, the drummer of the Subdigitals, pays a visit to Kadic to look for an opening act for the band's next concert. Everybody tries out, and Aelita turns out to be the one Chris is look…

There is a new recreation room at Kadic and William's clone is put in charge of it. Meanwhile, Jeremy has developed a program to get the real William out of Lyoko. However, the program malfunctions an…

The new virtual, submersible "submarine" (as Jeremy calls it) is almost complete, the last step being a secondary program that needs to be run by 4 PM the next day. However, when Aelita and Jeremy sta…

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 b…

Jeremy decides to teach Odd, Ulrich, and Yumi how to use the Supercomputer in case he or Aelita are unable to, being X.A.N.A.'s favorite targets. During the lesson, Jeremy is attacked by one of X.A.N.…

The group travels to one of X.A.N.A.'s replica sectors in the Digital Sea. Meanwhile, Aelita and Odd get into a fight after Odd's desire to sleep in gets them both in trouble. Furthermore, their argui…

The group turns to Jim for training, so they can be better prepared to fight against X.A.N.A.. However, things go bad when X.A.N.A. possesses a boar to attack them with, forcing them to put their trai…

When a comet passes near Earth, X.A.N.A. uses a laser-equipped military satellite to split it into chunks, simultaneously aiming the bulk of it directly at the factory. Aelita, Odd, and Ulrich are exp…

Jeremy, Aelita, Ulrich, and Odd go with the rest of their science class on a field trip to an island in the middle of a nearby lake to study water-based plant life. Yumi, not part of the class, remain…

Hiroki steals Yumi's diary and Ulrich finds it. Meanwhile, in a new attempt to free William from X.A.N.A.'s evil clutches, Jeremy creates a program to find William in the Digital Sea. When he uploads …

Jeremie has perfected his "Teleportation" process, allowing him to send his friends to the location of Xana's supercomputer in the real world to destroy it. He uses it on Aelita and Odd first, sending…

Having failed to destroy X.A.N.A.'s supercomputer in the Amazon, the group sets out to finish the job. Meanwhile, Odd's bragging gets the better of him, and he makes a bet with Ulrich not to brag for …

Odd tries to take Kiwi to Lyoko, but ends up absorbing him instead. As a result, Odd slowly begins to take on dog traits, such as enhanced smell and scratching himself with his foot. While Jeremy work…

Jeremy has developed a program to make the William clone smarter, but the learning curve is still problematic, as it tries to fling a glass into the air from a fork. Milly and Tamiya, overhearing the …

It's holiday time at Kadic and everyone is headed home. Aelita, however, has no home to go to. As she watches over Lyoko, she gets a message from Franz Hopper, who has constructed a simulation bubble …

When Odd breaks a mirror, a little bad luck follows and jinxes him everywhere, even on Lyoko. A bug in his virtual avatar spreads to Yumi and Aelita, causing annoying pauses and random devirtualizatio…

Jeremy wins a contest to take a flight in an armed fighter jet, even though it is Odd who entered him into the contest. However, just before takeoff, X.A.N.A. possesses the jet and sends it to destroy…

When Sissi's pen pal from Iceland, Brynja Heringsdötir, arrives at the school, all the boys swoon over her, making Sissi envious. When Brynja takes an interest in Odd, he ends up showing her the Super…

When Kiwi's mindless destruction becomes too much for the group to bear, they force Odd to keep him at the factory. As Odd drops him off, XANA possesses Jeremie's Kiwi Two robot, turning it into an ar…

Because of a surprise dorm inspection, Odd has to convince Yumi to keep Kiwi at her house. Jeremie, meanwhile, has located the next Replika, a copy of Sector Five. Its supercomputer is located on a ne…

Jeremie's cousin, Patrick, comes to visit. Jeremie isn't entirely happy about it, since Patrick is "super cool" compared to him. Discovering another Replika, Jeremie and his friends plan a mission to …

Aelita's first concert with the Subdigitals is coming up, but Aelita's stage fright threatens to get the better of her. Odd meanwhile, has to find an extra ticket so he can bring a date. When the conc…

Aelita finds a photo of herself with Franz Hopper at the Hermitage, with a mathematical equation in the background. Jeremie discovers that the program works as a reset feature to Lyoko, something not …

Odd is presenting one of his films, but is unhappy because his parents are coming. According to him, they never find fault in anything he does, which he finds dissatisfying because he isn't treated li…

When an embarrassing picture of Yumi is printed in the Kadic newspaper, she turns to Odd as the source. He manages to get Ulrich to take the blame, however, causing tension between him and Yumi. Putti…

In order to defeat XANA, whom they have vastly underestimated, Jeremie plans to design another multi-agent system to combat him. That, however, is still under development. In more immediate matters, J…

With the Skid gone and XANA's Replikas at unmanageable numbers, Jeremie continues work on his multi-agent system. Meanwhile, Aelita has nightmares about her father being killed by XANA. As Jeremie wor…

With their mission completed, the group looks back on all their fond memories of Lyoko. Sissi, meanwhile, plants a tracking device on Ulrich in order to discover their secret. When it comes time to sh…