|The Return of Impostor|
|Air date||November 20, 2013|
|Written by||Josep Maria Roca Peña|
The episode begins in Kadic, where they finished the repairs and arrangements and students must return to class. Odd is angry about the holidays have ended, but Jeremy and Ulrich don't agree for different reasons: Jeremy likes to study, and Ulrich supports not spend much time with their parents because every day are fighting and screaming. Yumi, Aelita and Hiroki are arriving by car and Yumi's parents explain that the girls had a great time in Ukraine. The Kadic's bell rings, indicating that they must return to class.
In a class of Mrs. Hertz, Mr. Delmas enters and informs all students that they will have a new student. Then comes Taelia, the girl who came temporarily in "The Girl of the Dreams" who Jeremy thought she was Aelita. The principal says that this time Taelia has come to stay in Kadic, because her legal guardian (because he has no parents) liked the school when he was first. When the class ends, Odd tells Taelia a joke that she looks like her friend Aelita, but Taelia when she hears the name "Aelita" get nervous and wants to know exactly who she is, and uncomprehending Odd calls Aelita. When she arrives, Taelia says Aelita: "I know who are you, as we have seen before, and I can see that you doesn't know grow". With this, she goes and Odd asks Aelita if she knows her or if Taelia is related to her parents and her family, but Aelita has no idea and is the first time she sees Taelia.
Odd and Aelita meet with Jeremy, Ulrich and Yumi, and talk about Taelia. Aelita Jeremy explained what happened, and Jeremy explains that when Aelita was virtual, Jeremy confused Taelia with her and even took her to the Factory. Yumi reminds him that made a return to the past, and she cannot remember anything. Aelita says is right, and doesn't believe that she knows her precisely for this. Odd makes a joke saying that she's "the defective copy of Aelita". Then he asks Aelita if she might be related to Franz Hopper, but Jeremy says it's an absurd idea and starts to talk about a program for Skid.
Meanwhile, Taelia meets Nicolas and Herb, who have heard the conversation of Taelia with Aelita. They say that Aelita and her friends are very rare, and even manipulated Sissi's mind. Taelia says that all he wants is revenge of Aelita, and Nicolas and Herb say they're are enemies of Aelita and the whole gang. Taelia says she like them, and they can be friends. Then comes Sissi's clone and Herb says Taelia is better than her. The clone, understanding nothing, makes a stupid comment and leaves. Taelia says, "This is the daughter of director?" and Herb says: "Aelita's group have been manipulated her mind." Taelia, with menacing voice, says: "Aelita will be expelled from Kadic…".
In Lyoko, X.A.N.A. activates a tower in the forest sector. Jeremy receives an alarm of the super-scanner on his laptop, and warns Yumi, Ulrich and Aelita. Then try to call Odd, but not pick up the phone. Meanwhile, Odd has turned of his mobile for anyone to bother and he's going to the Hermitage to discover the relation of Taelia and Aelita. Meanwhile, Jeremy tells Aelita, Yumi and Ulrich to go to Lyoko and cannot wait to Odd. Aelita asks Jeremy if Odd cannot answer his call for the X.A.N.A.'s attack, but Jeremy says that X.A.N.A. hasn't had time to attack so quickly, and said that surely Odd is in a date with some girl and doesn't want to be disturbed. Then Jeremy virtualizes Aelita, Yumi and Ulrich on Lyoko, and there are Kankrelats and Krabs.
In the Hermitage, Odd starts looking a photo of Aelita and her family, and he finds a photo of Aelita, Franz Hopper and… Taelia! In that picture Taelia is 2 years old, but Odd recognizes her perfectly. Odd goes to the factory with the photo. On Lyoko, Ulrich and Yumi easily defeat the Kankrelats and Krabs. But suddenly the piece of land where Ulrich and Yumi are separated from the rest, and Aelita is separated from the other Lyoko-Warriors. Yumi asks Jeremy for the vehicles, but then the Scyphozoa appears and possesses Aelita. At that time arrives Odd to the Factory, and says he knows who is Taelia: she's Aelita's cousin (daughter of Anthea's sister). Jeremy say they have a major problem.
Aelita starts walking towards the Digital Sea, and then appears X.A.N.A.-Sissi. Jeremy virtualizes the Overbike and the Overwing, and Ulrich and Yumi try to stop Aelita. Yumi fights agaist X.A.N.A.-Sissi while Ulrich will prevent X.A.N.A.-Aelita to jump to the Digital Sea. Jeremy virtualizes Odd, and gives his Overboard. After a struggle, X.A.N.A.-Sissi devirtualize Yumi. She's about to change her pink spirit, but Odd throws a laser arrow. X.A.N.A.-Sissi goes to fight against Odd. In the fight, Odd tells her that in Kadic, she has lost her two friends because they are now with Taelia. X.A.N.A.-Sissi ignores this and continues to fight against Odd, but she can desvirtualize X.A.N.A.-Sissi. But before her devirtualization, X.A.N.A.-Sissi throws his pink sword into the air, and X.A.N.A.-Aelita catches the sword.
X.A.N.A.-Aelita shoots a wave with the sword, which devirtualizes Odd. Then X.A.N.A.-Aelita begins to fight Ulrich, and X.A.N.A.-Aelita wins and Ulrich is devirtualized by X.A.N.A.-Sissi's sword. So X.A.N.A.-Aelita says with X.A.N.A.'s touch in his voice: "Yes!", but when everything seems to be over, Jeremy says: "Not this time" and launches Franz Hopper's program to restart the supercomputer just before Aelita jumping to the Digital Sea. A white wall runs along the forest sector, and Aelita is paralyzed. When finished, Aelita dropped, dispossessed. Aelita asks what happened, and Jeremy tells Aelita that she must deactivate the tower quickly. And Aelita deactivates the tower.
In Kadic, Aelita tells everyone that Aelita hadn't recognized Taelia because she was very young and now she has changed a lot, and Aelita also never knew his name. Then explain that Taelia parents died in a car accident, and she's an orphan. But is completely unknown why Taelia wants to revenge of Aelita if they met when Taelia was almost a baby. In Taelia's room, different to that used in "The Girl of the Dreams" (because now her old room is for Aelita) Taelia gets his phone and makes a call, saying "Yes, I am again, she's here", and ends the episode.