Cold Sweat
Air Date (US) Aired online
Air Date (France) November 3rd, 2007
Written by Bruno Regeste
Sophie Decroisette
Storyboard by Paul Beneteau
Alain Le
Season 4
Episode # 92
Production # 427
Preceeded by Bad Connection
Followed by Down to Earth

Cold Sweat is the 27th episode of Season 4 and the 92nd episode of Code Lyoko.


The episode begins with Yumi coming to school in the morning with her brother Hiroki. As she walks into the school campus, she finds an embarrassing picture of her has been printed in the Kadic Newspaper. Milly refuses to tell her their source for journalist reasoning while Tamiya hints that it was one of her closest friends who gave them the picture and was currently in the Rec Room. Yumi, in anger, goes towards the wreck room immediately convinced that it is Odd who has sent in the picture.

In the wreck room, Ulrich and Odd are playing fuzzball when Odd gets a call from Tamiya warning him that Yumi knows about him submitting the picture and is coming to confront him. Odd convinces Ulrich to take the blame for him which he does with some hesitation and obivous reluctance. When Yumi comes into the wreck room, she begins to threaten to tell Mr. Delmas every prank he ever pulled when Ulrich reluctantly tells her that it was him who gave Milly and Tamiya the picture of her. Yumi, obviously feeling betrayed, asks him why he did it. Ulrich says he doesn't have the "slightest idea" causing Yumi to storm out of the wreck room while demanding he never speak to her again. Ulrich was seen flinching as she slams the door. Odd comments that he's a really good friend, thanking him for covering for him. Ulrich stares at him and tells him, "Don't bet on that" and Odd looks at him in confusion. 

In the schoolyard, after being teased about the photo of her that was posted, Yumi runs into Jeremie and Aelita who inform her that they have discovered a new replika on the network. They are going to destroy it later that evening. That evening, Jeremie is sitting in the Lab overseeing the Skid docking procedure on the Ice Sector replika. They discuss who is going to get teleported to the replika's supercomputer, and Aelita suggests that Ulrich and Yumi go commenting that they were good together, but Yumi bluntly and flat out refuses. As they decide for her to go with Odd, Ulrich asks her "why not with him" and Yumi says Odd wasn't "dumb enough to make her look bad in front of the whole school". Ulrich then tells Odd he's "changed his mind" and they got to talk, but Odd avoids the subject as he and Yumi are then teleported to a Siberian Research Facility in the middle of a snowstorm.

As Yumi and Odd head over to the research facility which they can see in the distance, Aelita asks Ulrich what he did to make Yumi so furious with him. Ulrich says that it "seemed like he gave the picture of her to the Kadic News". Jeremie says that seemed more like something Odd would do and Aelita asks what he should do to get back on Yumi's good side and he says the only way was to tell her the truth.

Yumi and Odd go into the facility, while Jeremie tries to download a map over it. As he does Yumi asks Odd how Ulrich could have done such a thing to her and Odd tries to convince her the photo of her was funny, but Yumi says it was a "downright mean and nasty thing to do". She then adds that she's never been so furious at anyone in her life before and that she doesn't even think she can call Ulrich her friend anymore, making Odd uneasy. After Jeremie confirms that he has downloaded the map and located Yumi and Odd, he tells them to go down a corridor. Suddenly the Superscan warns that a tower has been activated on the replika. When Yumi and Odd come into the main room, they are shocked to see William materializing in front of their eyes. Jeremie tells Aelita and Ulrich to go and deactivate the tower. Ulrich and Aelita energizes outside of the Skid, and head for the tower on their vehicles.

Meanwhile, Yumi and Odd have William to deal with. He manages to deflect Yumi's fans with his sword, but Odd eventually hits him with his lazer arrows. They run over to a door on the other side of the room while William is disabled. As they approach the door, William manages to lock it using his mind. Jeremie begins to hack the lock. William tries to strike Yumi down with his sword, but Odd shoots him down just in time. Jeremie then hacks the lock and the door opens. Yumi and Odd proceed down the hallway as the door closes up behind them keeping William out.

On the replika, Aelita and Ulrich are coming up to the tower. A Megatank tries to stop them, but Aelita takes it out with her Energy fields. They see that the tower is on an ice bridge guarded by two Tarantulas, but heavy fire forces them to retreat behind an ice wall. In the Siberian Research Facility, William breaks through the locked door and chases after Yumi and Odd down the hallway. Jeremie tells them to hide somewhere until Aelita has deactivated the tower. Yumi and Odd decide to hide in some kind of a laboratory. They observe a few tanks which contain brains floating in some kind of liquid. Jeremie urges Ulrich and Aelita to hurry up in their effort to get to the tower. Ulrich decides to force his way through, and he uses his Super-sprint ability to sprint towards the Tarantulas. When he closes in on them he jumps up and throws one of his swords at one of the Tarantulas. Aelita takes care of the other one before it takes care of Ulrich. Aelita then runs into the tower and elevates to the top. In the research facility, William has found his way into Yumi and Odd's hiding place.

In the tower, Aelita is about to enter the Lyoko code when she realizes that the data in the tower can be used to free William. She starts to transfer the necessary codes and programs over to Jeremie. William is just about to take Yumi and Odd out, but luckily for them, Aelita is finished with the data transfer and enters the code Lyoko, which makes William disappear. Ulrich and Aelita think that their problems are over, but then Jeremie informs them that William has appeared on the replika and that he is heading straight for the Skid. Jeremie materializes the Overboard, and Aelita and Ulrich goes back to the Skid. They make it back just before William is about to enter the tower and terminate their mission.

After a short sword fight between Ulrich and William, Aelita manages to take him out with her energy fields. Back in the research facility, Yumi and Odd have finally made it to the supercomputer. They ask Jeremie on how to best destroy it and Jeremie informs them that trashing it would not be wise. Just then a window opens up on Jeremie's screen. It shows that X.A.N.A. is taking energy from all of the replikas, but have no idea why. Then the ground begins to shake on the replika, and Ulrich and Aelita are both startled and puzzled.

Without notice XANA has created giant of a monster and it is slowly heading for the Skid. Jeremie yells that Ulrich and Aelita must run away. The monster is so huge that neither Aelita's Energy Fields or Ulrich's swords have any effect on it. The monster then slides his huge arm, shaped like a sword, along the ground straight towards Ulrich and Aelita. They try to turn around and run away from it, but they are devirtualized within a fraction of a second. The monster then turns its attention towards the Skid which is now defenseless. Jeremie decides to bring Yumi and Odd back in, and he energizes them back to the Skid just as the huge monster is closing in on it. Jeremie releases the docking mechanism just before the monster grabs the tower and slams his arm after the Skid. They make a narrow escape.

Back on Earth Odd decides to name the monster the Kolossus with a "K" like in KO. Jeremie realises that they have to change tactics and find a more efficient way to destroy replikas. As the group heads back to the school, Ulrich demands Odd tell Yumi the truth about the picture or otherwise he will but Odd still doesn't wish to confess the truth. Just as Ulrich begins losing his patience altogether, Yumi comes up to talk him.  Odd leaves to head to bed thus leaving Ulrich alone with Yumi. Yumi explains to Ulrich her theory about why he submitted the picture to the Kadic News; he did it to make her notice him more. Yumi then decides to forgive Ulrich and kisses him on his forehead and tells him to talk to her next time instead of doing something dumb. As she walks away, Ulrich can be seen blushing as he stutters out a goodnight to her. But, a few minutes later, as Yumi is heading into her house (and without Ulrich knowing it) Odd calls Yumi and tells her he can't go on acting like a coward and admits the photo prank was him. Yumi then punches her house gate open, angered once again. 

The next day, Milly and Tamiya have another big Kadic news story; a picture Yumi took of Ulrich and Odd coming out of the shower as revenge. We then see Ulrich chasing Odd around the schoolyard in fury, and the episode ends.


  • The original French name for this episode is Sueurs froides.
  • This is the only time Odd has used his Cat Run during a replika mission.
  • This is the only time X.A.N.A. has managed to teleport William. Interestingly, he used a tower when it was seemingly unnecessary, as he used the Scyphozoa to copy the Skid's files, so he probably could have teleported William without it.
  • When the Kolossus let go off the tower, it was slanted at an angle; this is the only time a tower hasn't been seen perfectly upright.
  • The Kolossus makes it's Code Lyoko debut


ca:Suor freda es:Sudor frío fr:Sueurs froides pl:Odcinek 92 "Zimny pot" pt:Suando frio ru:Холодный пот