|Down to Earth|
|Air Date (US)||Aired online|
|Air Date (France)||November 3rd, 2007|
|Written by|| Bruno Regeste|
|Storyboard by|| Roland Boschi|
|Preceeded by||Cold Sweat|
|Followed by||Fight to the Finish|
The episode starts out with all of Team Lyoko, except Jeremie, standing in front of the vending machine. Odd is talking about how Aelita and Jeremie spent an entire weekend together, and only worked. Then claims that they are worse than Yumi and Ulrich. Aelita announces her concern about Jeremie's constant work on the supercomputer ever since they found out that X.A.N.A. controls a huge number of supercomputers all over the world. Aelita then gets a call from Jeremie, but he tricks her by standing right behind her while talking to her. He then says that he has finally found a way to wipe out X.A.N.A.
In Jeremie's dorm room he explains what he has been working on. He is programming a multi-agent system with the aid from the data collected by the Skid, Franz Hopper's notes and the data he sent to them when he escaped out into the Network. But then Aelita says that it could be dangerous to create such a program, and she reminds Jeremie about the fact that X.A.N.A. is a multi-agent system too, as well as the time when the Marabounta tried to destroy Lyoko. But Jeremie says that this time he will not launch the program until he is absolutely sure that it will work. He also says that he's been working on a program for freeing William from X.A.N.A., using the data that Aelita got from the Tower controlling William's teleportation in the last episode.
Jeremie explains that in order to free William, they have to go to Replika 4's supercomputer and run the program when William is devirtualized. The others aren't 100 percent convinced and worries about the difficult task in devirtualizing William while keeping a lookout for X.A.N.A.'s new monster; the Kolossus. But Jeremie is totally relaxed and with a fair amount of excitement, he orders everyone to the factory.
Meanwhile out in the school yard, Jim is trying to get the William Clone's attention. Jim asks why the clone didn't respond to his call, and the clone says that he doesn't have a phone. Jim informs him that his parents are there to see him. He, as stupid as ever, ask who they are. Jim gets irritated over the clone's stupidity and directs the clone the Principal's office to meet his parents; William's parents have however never met the clone before. In the Principal's office, Mr. Delmas is informing William's parents that their son has changed quite a bit during the last few weeks. He then mentions a trip William and his parents went on, but William's father says they never went on a trip. The clone then knocks on the door, Delmas says "come in", but nobody opens the door. Delmas says a bit louder "come in, I said". When nobody still doesn't open the door, Mr. Delmas walks over to the door and opens it. He asks the clone why he didn't come in, and the clone answers that the door wasn't open. William's father says that he's indeed changed.
In the factory, Jeremie is sending Team Lyoko the coordinates for Replika 4, as the Skid is emerging through Lyoko's Network Access Gate. Aelita rotates the Skid into horizontal position and heads off through the Network.
In the cafeteria, William's parents are having lunch with what they think is their son. Rosa lists up the menu, but William's mother ask if she has something lighter than sour crout and tuna casserole. Rosa says that sour crout is light. When William's clone comes to have his portion, Rosa asks him how it's going. The clone moves his tray back and forth and says that it goes in any direction he wants it to. Rosa laughs and gives him his portion saying that it will "stick to his ribs". The clone takes this statement literally and says that he can't eat it if it's on his ribs. William's parents are shocked over the clone's stupidity.
In the Network, the Skid hovers over a network hub, and after a few seconds it dives in it. The Skid travels with hyper speed towards its destination. In the cafeteria Jim comes over to greet William's parents. He says that their son is really quite a piece of work. The clone then makes a stupid statement where he reveals that he is in fact a polymorphic clone. Jim is surprised and after a few seconds he walks away. William's mother asks why William doesn't call them much at the moment. The clone says that if he called them they wouldn't be home because they are right in front of him.
In the Network the Skid stops in front of Replika 4's access gate. Aelita connects the Skid to it and Jeremie opens up the gate. After a few seconds the Skid emerges out of the Digital Sea and rises up to a huge ice plateau. Jeremie directs them to a tower nearby. Aelita and Odd are teleported over to the Siberian Research Facility. They make it to the entrance and go in. Jeremie tells them to make it fast before XANA counter attacks. Odd, who has been there before and knows the way, leads Aelita down the corridor to the main room. Back at the school, William's parents are in the Principal's office claiming that the William they see can't be their real son. Mr. Delmas agrees that William has been behaving strangely for the past few weeks, but says that the William they see is the one and only William Dunbar they know. William's father then asks about the trip they supposedly went on. Delmas says that it was the trip they took overseas before William came down with a terrible flu. William's parents are puzzled and wonders what Delmas is talking about.
On Replika 4, Yumi and Ulrich are guarding the Skid. Yumi is excited about bringing the real William home. Ulrich hopes that his clone is keeping out of trouble in the meantime. Yumi then hesitantly says to Ulrich that she hopes that when they bring William back, that he won't be jealous if William begins to start hanging around her again. Ulrich reminds her that they are just good friends and asks her if that's all they were and she awkwardly agrees. Jeremie suddenly cuts in and warns them of William and two mantas approaching. Jeremie programs their vehicles and tells them to slow William down. Suddenly Jeremie sees that X.A.N.A. is drawing energy from all of the replikas and that worries him. In the Siberian Research Facility, Aelita and Odds get a small shock when they enter the main room. A vast number of robots are lined up on the floor like an army waiting for orders. Jeremie concludes that this must be X.A.N.A.'s secret plan; to use an army of robots to enslave all of mankind. He urges them to get to the supercomputer as fast as they can.
On the replika, Ulrich decides to take on William while Yumi deals with one of the mantas. Yumi warns Ulrich not to devirtualize William too soon. In the research facility, Odd and Aelita are walking through the army of robots to the door on the other side of the room. Odd jokes about the robots not making much conversation. Jeremie begins hacking the lock to open the door leading out of the room. Odd makes another joke about one of the robots moving, and Aelita is a bit angry when she falls for it. Odd makes the same statement again, but this time it's for real. The robots start to move towards Aelita and Odd. On the replika, Ulrich manages to destroy William's black manta and soon after engages in a sword fight with William. In the research facility the robots begin firing lasers at Odd and Aelita, who shoot lazer arrows and energy fields back at the robots. Jeremie finally opens the door, and Aelita and Odd rush through the door and through the corridor on the other side with the robots chasing them. Back on the replika, Yumi destroys the last manta while Ulrich tries to keep William busy.
It goes fairly well for a while until William uses his super smoke ability and hides in a nearby lake. Soon after, the ground begins to shake and the Kolossus rises up from the lake with William standing on his right shoulder. At the research facility, Odd and Aelita have made it to the door leading into the supercomputer room. But the door is locked and until Jeremie can open it, they have to fight of the robots in a tight corridor. On the replika, Ulrich makes a leap over to the Kolossus' arm and begins to climb towards where William is standing. He notices a target on the Kolossus' sword as he climbs up.
Meanwhile, Yumi is on her Overwing trying to take the Kolossus down. She stops in front of its head and throws one of her fans towards the face of the Kolossus. But the fan only slightly damages the Kolossus, and Ulrich says that there is a second target on its arm. William is standing tall on the Kolossus smiling at Team Lyoko's hopeless attempts to take out the Kolossus, which is wading through the lake towards the Skid on the plateau a good step away from it. Jeremie tells them to concentrate on keeping William busy while he deals with the Kolossus. Jeremie launches his unfinished multi-agent program and freezes up the lake thus paralyzing the Kolossus. Jeremie can now open the door to the supercomputer room. Odd tells Aelita to go in while he keeps the robots at a distance. Jeremie tells Aelita to go to a terminal next door so that he can dictate the program to her. Ulrich has finally made it up to where William is and engages him in a sword fight.
Yumi tells him to take it easy, but Ulrich's anger towards William tells him otherwise. Meanwhile, Aelita is typing in the program to free William while Odd is fighting of the robots in the corridor. He manages to shoot down quite a few, but the robots finally outnumber him and de-teleports him back to the Skid. Aelita has finished typing in the program and is now ready to launch it. Jeremie tells Yumi and Ulrich to devirtualize William when he gives them the signal. But the Kolossus is about to break free from the frozen lake, and it quickly devirtualizes Yumi, who is circling around it, by smashing her in with its sword. In the research facility, the robots have found their way into the room where Aelita is, and she defends herself by throwing energy fields at them.
The battle between Ulrich and William rages on as the Kolossus has made it out of the lake and is closing in on the Skid. Ulrich and William eventually end up beneath the Kolossus, and Ulrich manages to pin William to the ground. Jeremie gives Aelita the signal to activate the program. But William escapes using his super smoke ability. Ulrich is caught off guard and is devirtualized when the Kolossus steps on him. Aelita is also de-teleported by the robots, and Jeremie watches in despair as their mission is about to fall to pieces. The Kolossus is getting even closer to the Skid, and William laughs while exclaiming "victory" as he watches it. Suddenly he is devirtualized by Odd who has snuck up behind him. The program does its magic and William appears in the scanner room a few moments later as his old self again. William emerges from the scanner back to his old self. But on the replika, Odd sees that the Kolossus is right next to the Skid and says to Jeremie that he can't do anything from where he is.
Aelita wakes up just in time to see the Kolossus raise its sword and smash the Skid off of the tower it was connected to. Aelita is tumbled around inside the cockpit as the Skid crashes to the ground and slides across the plateau stopping at the edge. One of the Nav Skids is torn off and hurtles into the Digital Sea. Jeremie is horrified over what he sees. The Skid then tilts over the edge of the plateau and falls to its doom leaving a smoke trail behind it and another one of its Nav Skids torn of. The Skid explodes before it reaches the Digital Sea. Jeremie fears that he will never see Aelita again, but she emerges from one the scanners, and says that she was devirtualized just before the Skid exploded.
In the Principal's office, Sissi has joined the group and is agreeing with William's father that something funny is going on. She says that William started acting weird after he started to hang out with Jeremie and the others. William's father demands to talk to Jeremie to find out what is going on. When they get to his dorm room, they find that nobody is there.
Further down the corridor, Yumi, Odd, Ulrich and the real William are hiding behind a door. Yumi tells Aelita over the phone that now is the time. Aelita gives the signal to Jeremie and he deactivates the tower controlling the William Clone. The clone disappears into thin air, and Jim is horrified to see that William is gone. But when Mr. Delmas takes a look, the real William has taken the clone's place. William ensures his parents that everything is okay with him and they are relieved, recognizing their son.
Later in the school yard, Team Lyoko is thinking about how to fight X.A.N.A. now that the Skid has been destroyed. Jeremie says that he will continue working on his multi-agent program later that evening. William then waves at Yumi from a distance and she waves back as she smiles at him. Ulrich, who is watching, casts a jealous look and he glares at the scene as the episode ends.
- The original French name for this episode is Retour.
- Down to Earth is also a name of a song.
- When William is re-materialized, he is in his seasons 2-3 attire, but when he was sent by X.A.N.A. in A Lack of Goodwill, he was in his season 4 attire. Also, when William got to school, he seemed to have changed his clothes. Likely in A Lack of Goodwill it was XANA's doing for him to have updated attire just because he felt like re-arranging the pixels so he could confuse Milly and Tamiya
- This is the only time that a Lyoko Warrior has been seen sent back to the Skid during a replika mission after visibly sustaining heavy damage, although Yumi and Ulrich were de-teleported off-screen after falling to the cyber spiders in Bragging Rights. Also in A Lack of Goodwill, Aelita and Ulrich are forced to de-teleport each other since Jeremie was away fighting X.A.N.A.-William.
- This is the second time Aelita has been missing her bracelet as a Spectre.
- Down to Earth is a reference to William's return to the Lyoko Warriors.
- This episode marked the only appearance of the Siberian Robots.
- This is only time William's mother appear in the series.