|The Big Loss|
|Air date||December 30, 2013|
|Written by||Josep Maria Roca Peña|
In Search of Sissi
The episode begins on a Sunday in Kadic, where the Lyoko-Warriors are gathered in Jeremy's room ready for the mission to recover Sissi. Jeremy writes something on his computer and pulls out a CD, and said to contain the data that Aelita took in the tower which X.A.N.A. activated in Xanadu, because X.A.N.A. sent as X.A.N.A.-Sissi to Earth, Aelita took control the programs that X.A.N.A. uses to controlling Sissi. He also explains that to recover Sissi, one of them will have to devirtualize Sissi with their weapons, and he has improved their weapons: Odd has a million laser arrows on each arm without being recharged, the Yumi's fans will fly to target without aiming, and Ulrich can throw lightning with his katana. But these changes are temporary, as they need a lot of energy supercomputer.
Someone knocks on the door of Jeremy's room, and he says, "Come". But no one opens the door, and Odd opens the door and Sissi's clone are outside the room. The clone asks why they are all gathered in the room of Jeremy and Odd says they have an important mission. Sissi's clone says he has a message from Mr. Delmas, who wants to see Odd for themes of delegate. Odd tells the clone she have to tell Mr. Delmas that Odd is sick, and Sissi's clone says: "But you seems to be healthy, why should I say you're sick? It's illogical". Odd says it isn't unreasonable and she must do it, as it's very important. Clone says: "It's important… I'll do it". The Lyoko-Warriors leave Jeremy's room and go to the park to go to the Factory, while Sissi's clone goes to the principal's office.
The Lyoko-Warriors reach the Factory, Jeremy says that in order to run the program, should go to Xanadu. Then Jeremy virtualizes Aelita and Yumi and then Odd and Ulrich to sector 5, and goes to the Skid. But in the Digital Sea, after crossing the virtual wormhole, they find a group of Kongres that they're protecting Xanadu. Aelita says they have a problem, but Jeremy says he will run a program to confuse the Kongres. And then begin to appear Skid copies, and the Kongres don't know where to shoot. Some copies are destroyed, but the real Skid breaks into Xanadu. Odd says: "Goodbye, fish face", and they enter into the first sector of Xanadu. Jeremy says Aelita to search a tower to connect the Skid, and they must wait for X.A.N.A.-Sissi.
The Lyoko-Warriors disembark from Skid, and Aelita enters into the tower. Odd gets bored and starts shooting laser arrows into the air. Jeremy says that even he has a very large number of arrows, he don't waste it. Then a group of flying Tarantulas, Kankrelats and Bloks appear, and Ulrich, Odd and Yumi get to fight. Yumi throws her two fans and she can destroy all the blocks, Odd can destroy all the Kankrelats throwing them a lot of laser arrows but he receives some impacts, and Ulrich manages to destroy a few flying Tarantulas with rays of his katana. But a flying tarantula devirtualize Odd.
Meanwhile, in the principal's office, Sissi's clone says Mr. Delmas that Odd is sick, but he believes Odd have manipulated her to cover him because he don't want to talk about academic issues in Sunday. Mr. Delmas says Sissi's clone that they will go to Odd's room. In Xanadu, between Yumi and Ulrich they can destroy the flying Tarantulas, and then a group of Mantas and X.A.N.A.-Sissi on a black Manta appears. X.A.N.A.-Sissi says: "I see you have the weapons upgraded, but you can't defeat me". Jeremy tells Aelita: "You can leave the tower, the fish has taken the bait". Then Aelita go out of the tower and tells Yumi and Ulrich: "Ready?" And all three say, "Go for it" and they start running to attack X.A.N.A.-Sissi.
Aelita and Yumi destroy several Mantas, and Ulrich destroys X.A.N.A.-Sissi's black Manta. But X.A.N.A.-Sissi uses her pink spirit and appears behind Yumi, and with his sword she can devirtualize Yumi. Then she goes to fight against Ulrich and they start a sword fight, but X.A.N.A.-Sissi can devirtualize Ulrich. X.A.N.A.-Sissi goes for Aelita in her pink spirit, and when she returns to normal, she devirtualizes Aelita and says: "I win!" but that Aelita was a decoy, and the real Aelita devirtualizes X.A.N.A.-Sissi and says: "You are mistaken, we've won us". Jeremy runs the program, and Sissi's ID card appears in the supercomputer and Jeremy detects something coming out of the scanner. Jeremy, Yumi and Ulrich down to the scanner room and discover that Sissi isn't possessed by X.A.N.A, but is lifeless.
Jeremy says they could materialize Sissi's body but not her spirit, as the brain of Sissi is somewhere in the Digital Sea. Yumi says: "Another mission…" and Jeremy materializes Aelita. In Kadic, Mr. Delmas and Sissi's clone go to Odd's room and find that no one is there, but behind Odd appears and says faking a sick face, "I have gone to the park to get some air, but I'm dizzy". Mr. Delmas says: "Sissy, I'm not sorry I don't believed you. You can go back to your room. And Odd, as I see that you do not feel well, we'll talk another day". Odd enters his room, with the rest of the Lyoko-Warriors. Odd asks if they have recovered Sissi, and Jeremy says, "Yes and no". Odd is surprised by this response, and Jeremy says they have Sissi's body, but they have to search their spirit in the Digital Sea. The good news is that X.A.N.A. has lost X.A.N.A.-Sissi as a weapon, and ther're closer to defeat X.A.N.A.