Code Lyoko Wiki
Code Lyoko Wiki
This article is for the episode. For the character, see Waldo Schaeffer.

Franz Hopper is the twenty-third episode of Season 2 and the forty-ninth episode of Code Lyoko.


The episode starts with Jeremie discovering five towers that have been activated simultaneously and asks the group to meet at the Factory. However, when they arrive in the lab, they find a man at the interface, somehow deactivating the towers directly from the keyboard. The man identifies himself as Franz Hopper, the person who created Lyoko and X.A.N.A..

He explains that X.A.N.A. is a multi-agent system, and that he, Hopper, lost control of it when X.A.N.A. became sentient. He also says that he created Aelita to be the guardian of Lyoko. Skeptical, Ulrich asks where he has been for the last ten years, to which Hopper replies vaguely that he had been taken prisoner by X.A.N.A. and had only recently managed to escape. He promises he will find Aelita's antivirus and shut down the supercomputer.

The next morning, Jeremie receives a call from his father, Michael Belpois, wishing him a happy birthday. It is also revealed that Jeremie's parents want him to leave Kadic Academy and transfer to a school for gifted children, and that Jeremie has been keeping this information from his friends while he considers his options. During the call, Aelita, Ulrich, Odd, and Yumi enter his dorm to give him a birthday present. Jeremie cuts his father off and hangs up to receive his gift, a framed picture of the five Lyoko Warriors hand-drawn by Odd. After thanking them, Jeremie suggests they go to the Factory and check up on Franz Hopper.

While they're there, Franz tells them that the scanners were not ready for use on humans and that being virtualized in them may cause cell degeneration. They decide to use the supercomputer to examine Odd, Ulrich, and Yumi for such a problem. Hopper finds that Odd and Ulrich appear to be fine, but that Yumi is suffering from brain cell degeneration. It is heavily implied that Yumi's diagnosis is terminal.

Back at school, the news begins to cause a rift in the group. Ulrich and Odd blame Jeremie, claiming it was irresponsible of him to not know about the negative health effects of virtualization, and refuse to accept his apologies. Yumi appears scared, hurt, and resentful, and asks to be left alone. Aelita, however, defends Jeremie, saying that it was by his efforts that she was able to come to Earth and without the scanners she wouldn't be here. Tensions culminate in an argument at dinner, with Jeremie and Aelita leaving Ulrich and Odd's table. Later that night, Hopper calls Yumi and tells her to bring the others to the Factory in the morning.

The next day, Franz tells the group that he knows how to make an antivirus for Aelita and that all he needs is data from Sector Five. Jeremie protests, reminding the others of the risks the scanners pose to their health. Hopper responds that they have no other option, and coolly advises Jeremie to "stay out of the way" and even blames him for ruining his own diary. Jeremie becomes frustrated, claiming he is being blamed unfairly for everything before storming out of the lab.

Jeremie returns to his dorm room, still fuming. He calls his father and tells him he wants to go to the school for gifted children, and his father complies, saying that he will be there the next day to pick him up. However, after calming down, Jeremie slowly begins to notice holes in Franz Hopper's story, particularly the part where Hopper told him "...and you're the one who let X.A.N.A. destroy my diary!". Realizing there is no way Hopper could have known about that incident, Jeremie quickly deduces that Hopper must be under X.A.N.A.'s control.

Meanwhile, Hopper virtualizes Odd, Ulrich, and Yumi directly into Sector Five to clear a path before Aelita is virtualized. When they reach the Core Zone, they are confronted by an unusually large number of Creepers, and Hopper reveals to them that he has improved their weapons. The three dispatch the Creepers with ease, and Ulrich touches the Key, stopping the countdown. Franz then tells Aelita, who has been waiting in the scanner room, that he is ready for her to be virtualized. However, Jeremie arrives with his laptop just before she enters the scanner, and he and Aelita have a private conversation. Aelita is then virtualized, but she appears on a completely isolated platform in the Desert Sector, much to her confusion. Jeremie then goes up to the Lab and confronts Hopper, revealing that he knows his true identity as Polymorphic Clone. Exposed, "Hopper" remarks that Jeremie is very clever, but that he is too late.

In Sector Five, a group of monsters block Ulrich, Odd, and Yumi's path, and the Hopper clone begins tampering with their Lyoko avatars by deactivating their weapons, leaving them defenseless. The trio manage to escape down another hallway, and Yumi begins to suspect that they've been double-crossed. Hopper then modifies their avatars further, making it so that they will not return to Earth if they are devirtualized. Meanwhile, in the Desert Sector, the Scyphozoa arrives and captures Aelita.

Ulrich, Odd, and Yumi manage to fight their way through a group of Creepers using hand-to-hand combat before coming across an activated tower deep within Sector Five. The trio become convinced of foul play as more Creepers arrive and corner them on the edge of a platform. Meanwhile, the Scyphozoa successfully drains all of Aelita's memory, but it begins acting strangely. It is revealed that the Aelita on Lyoko is a decoy and that the real Aelita is in the scanner room, controlling the decoy using Jeremie's laptop. Furious, the Hopper clone collapses into a spectre and vanishes, giving Jeremie control of the interface once again.

Jeremie manages to fix all of Hopper's modifications just before Ulrich is devirtualized by the Creepers. With their weapons returned to them, Odd and Yumi begin fighting back against the Creepers, as well as a Manta. Meanwhile, the real Aelita is virtualized into the Ice Sector, where the Transport Orb takes her to Sector Five.

In the lab, the spectre returns and enters Jeremie's windpipe, causing him to slowly asphyxiate. Ulrich comes up from the scanner room and finds Jeremie writhing in pain on the floor. Jeremie fights to breathe as Aelita rushes to the tower. Once she deactivates it, the spectre is forced out of Jeremie's body, saving his life.

The next day, the group is talking in Jeremie's dorm. Jeremie informs Yumi that he looked into her condition and found that the Hopper clone had been lying; there is nothing wrong with her. Jeremie's father then appears at the door, ready to pick him up. Jeremie tells his father that he has changed his mind, and does not want to go anymore. His father takes the news well, but before leaving he asks Jeremie to call home more often as he and his wife are worried about him. When asked where he was going by the group, Jeremie replies that he does not plan on going anywhere before fixing the picture that Odd gave him.


  • The original French name for this episode is the same as the English.
  • Jeremie turns 13 in this episode, revealing his birthday to be somewhere near the end of the French school year.
  • Chronologically, this episode takes place after the events of Temptation and Is Anybody Out There?, but ended up premiering before either of them for unknown reasons.
  • This was the last episode to feature both Frédéric Lenoir and Alain Serluppus as writers.
  • The gifted school mentioned in this episode was first established in Plagued.
  • This episode marks the first appearance of Jeremie's father, Michael Belpois.
  • This episode marks the first time that a clone was made and controlled from a laptop.
  • This is the first episode where a tower is seen within Sector Five.
  • This episode marks the first time the Lyoko Warriors were virtualized directly into Sector Five, proving that direct virtualization there was possible, though Jeremie would not learn how to perform this himself until Double Trouble.
  • This is the only episode where Ulrich uses energy slashes with his saber; this same power would later be channeled through William's Zweihänder as of Final Round.


  • In one shot when the Hopper clone explains to the Lyoko Warriors that the virtualization process is very dangerous to use on humans, the Supercomputer is gone.
  • When told by the Hopper clone to stay out of the way, Jeremie complains that it is unfair for him to be accused of "everything that's happened", and argues that the group all turned the supercomputer back on together. Yet in the first part of the prequel, X.A.N.A. Awakens, Jeremie is shown to have found and restarted the supercomputer on his own. (He could be referring to the events in episode 26, when he did restart the supercomputer with all of them there, due to Aelita passing out.)
  • Even after it is destroyed by X.A.N.A. Franz Hopper, Ulrich's katana can still be seen in its sheath in certain shots. In other shots the sheath is gone entirely.