It was in the Ice Sector where Aelita, Yumi and Maki were making their way towards the tower.
"Did you find the tower?" Jeremie asked.
"Yes...but it seems offly calm." Maki said.
"Stay on your guard." Jeremie said.
"Maki, you stay and protect Aelita, I'm going to check around." Yumi said.
"Alright. We're counting on you." Maki said.
Aelita and Maki then entered the tower and checked it out. "Jeremie? I'm not sensing anything out of the ordinary. Are you sure this is the right tower?" Aelita asked.
"That was what the scan picked up. At least what it told us." Jeremie said.
As Yumi stood watch outside, she was suddenly attacked and released a loud scream.
"Yumi!" Maki called as she left the tower. She couldn't find Yumi in sight. "We have a problem. Yumi's gone."
"What?! She couldn't have just vanished!" Jeremie gawked. "Wait, hang on, a scanner just opened. I'll bring Maki back first and head right down."
Jeremie got off the computer before running down to see Maki looking at an unconscious Yumi inside the scanner.
"She seems to be in critical condition. I'll take her to the nurse." Maki said.
It wasn't till later in the day that the student group saw Maki carrying Yumi to the nurse's office.
"Now how exactly did this happen?" the nurse asked.
"She has been studying a lot, and she suddenly felt sick and collapsed in the quad." Maki said.
"Thank you. I'll take good care of her." the nurse said. "You can go now."
"Thank you." Maki said as she left.
As soon as Maki had left, Yumi had soon regained consciousness.
"Well, feeling better?" the nurse asked.
Yumi was soon getting up and tried to leave.
"I know your feeling better, but you need to lay down." she said before Yumi grabbed her hand as the nurse screamed at what happened next.
Meanwhile in the quad…
"She was really devirtualized, just like that?" Shuichi asked.
"The weird thing was that she still had all of her life points when it happened, and was unconscious at the scanner." Miu said.
"Hmm...something doesn't feel right…" Mark mused.
"What doesn't feel right?" a voice asked as they saw Yumi next to them.
"Guess you're feeling better, huh?" Odd said.
"Can you tell us what happened?" Francisca asked.
Yumi just shrugged and tried to walk off, but Ulrich grabbed her.
"Are you sure you're okay?" Ulrich asked.
"I'm fine. I'm just tired. Let's go over to the factory." Yumi said.
"Not in your condition. Besides, it's lunch time." David said.
"Agreed, you should join us. I heard the main lunch is hamburgers today." Double D added.
Meanwhile on Lyoko, Aelita was in a tower til she felt the disturbance. She ventured out to see a large bubble in the distance. She then ran towards it.
Back at Kadic, the group sat down to eat.
"So you don't remember anything?" Jeremie asked.
"Could the scanners have some kind of bug?" David asked.
"That could be it. They might be becoming a health problem. And speaking of health problems…" Fuyuhiko said as Sissi headed over to them.
"Ulrich. What do you say we get together after school?" Sissi asked.
"You and me after school? No thanks!" Ulrich said.
"Why don't you go out with her? She seems really nice and pretty." Yumi said.
"Okay, that is definitely weird. Yumi would never say something like that. At least to Ulrich." David said.
"Well, someone is finally wising up. Later, Ulrich." Sissi said walking off.
"What's with you today?" Ulrich asked.
"Nothing. I just think it is time for you to go out with Sissi." Yumi said before Delmas's hand was on her shoulder.
"Miss Ishiyama...I'll have to ask you to come with me to my office." Delmas said.
Later in the Principal's Office…
"I am shocked about what you did to Miss Yolanda. 2 hours of detention! Now!" Delmas said as Yumi just stood there. "I sense that you are troubled. Care to tell me about it? It is my job to help you." he asked as she still stood there. "If you keep this up, I'll have to call your parents."
"Not my parents." Yumi said grabbing the phone before Delmas could. She then bashed him in the head with it, knocking him out as she walked out without a care.
Meanwhile in Jeremie's room…
"As soon as I got close to the area where the guardian was, the monsters attacked me." Aelita said.
"You shouldn't have left the tower like that." Jeremie said. "But this may have something to do with what happened to Yumi."
"Should I go back there?" Aelita asked.
"Not alone. I'll send Ulrich and Odd as backup." Jeremie said.
"But what if the same thing happens to them?" Aelita asked.
"Hmm...you're right. We shouldn't risk it." Jeremie said. "Just be careful."
"Okay." Aelita said as she left. As soon as she left, Yumi quickly entered the room.
"Yumi! What did the principal want?" Jeremie asked.
"We have to go to the factory now." Yumi said.
"But there's no reason to go and you need to rest." Jeremie said.
"I need to go to the scanner room." Yumi said.
"No. Not until I give the order." Jeremie said before Yumi leaned closer to him and removed his glasses.
"I need to go to the scanner room." Yumi said.
"Uh…" Jeremie said blushing as Yumi leaned closer just as the others opened the door.
"Hey Jeremie, is...whoa...uh...this is not something I was expecting." Pit said.
"Yumi, personal space!" Mark said. "Respect it!"
"Mark, that's not the issue right now." David said as Ulrich ran off. "Wait! Ulrich!" he said going after Ulrich.
"Wait! It's not what it looks like! Ulrich!" Jeremie shouted, going after him.
"Way to go." Odd said as everyone else went after, leaving Yumi behind as she smiled.
It was soon after that classes ended for the day…
"Listen, Ulrich. Yumi's not herself. She's not in her right state." David said. "But… Maybe Aelita has found something that might help us bring her back to normal."
"Fine. Let's go." Ulrich said.
Meanwhile on Lyoko, Aelita had gotten close to the guardian and saw the inside and was shocked. Before anything else could happen, the monsters began to attack and she ducked into the hole in the ice.
Back at Kadic as the group returned to Jeremie's room, they saw that everything was torn apart.
"Oh… This is a disaster!" Mayumi said.
"I know. Wait...who was the last one to leave the room?" Double D asked.
"No...it's not possible." Ulrich said.
"She has been acting strange." Odd said.
"Okay, Yumi hasn't been herself, but the enemy is Xana. He's launched an attack." Ulrich said.
"So...are we going to the factory?" Yumi asked as she arrived.
"I'll have Sectonia and Barbara come, just in case." David said.
"Uh...somehow I don't think that's gonna be possible." Asta said pointing out to a large swarm in the distance over where the Sunny and factory were.
"Oh, this is just great." David said.
"Wow...these kingdoms really have a terrible sense of timing." Flamberge said.
"Eh...they'll just join us once all the bugs go down." Luffy said.
"Yeah...this is a walk in the park for them." Dan said.
As they hurried over to the factory, the group that stayed on the Sunny was quick to start defending it against the numerous dragonfly-like creatures attacking them.
"Yanma and a Yanmega...what are the odds?" Sectonia said.
"More likely than usual, apparently." Eddy answered as he punched one of the Yanma. "How come these guys can talk, by the way? Most of the Pokémon we've seen can't do that."
"The Kingdoms are unique. Pretty much all Pokémon who come from them have the ability to speak." Erza said.
"Either way, it looks like we've got some exterminating to do." Captain Cold said.
"Seems the best way to tackle this...would probably be to take out their commander...the Yanmega flying overhead." Leopardmon said.
"And they're the fastest Bug-types. We'll need to match him speed for speed." UlforceVeedramon said.
"Though that shouldn't be a problem for you." Sanji said.
"Of course. Just leave it to me." UlforceVeedramon said.
"Foolish...creature. You can't take me or my soldiers down. We're Chrysalia's top Air Force! Shoot him down! Sonic Boom!" Yanmega said as he and the Yanma started unleashing powerful Sonic Boom attacks.
"Victory Sword!" UlforceVeedramon said as energy blades came out of his bracelets and he slashes away at the Yanma. "Now for my new technique. Dragon Impulse X!" he surrounds himself in the aura of a dragon, and rams against Yanmega. He then unleashes both Ulforce Sabers and slashes Yanmega in an X-shaped pattern.
"Not...possible." Yanmega groaned as he was seen falling out of the air.
"He's taken out the commander!" one of the Yanma said as they all swarmed to collect their fallen leader before fleeing.
"That was amazing, Veevee!" Sectonia said.
"Ah, it was nothing. I've been working on that one with the other Royal Knights." UlforceVeedramon said.
"Yeah, it shows." Vashyron said. "We ended up chasing off the entire swarm of them."
"I wonder how the others are doing." Sectonia said.
At the Factory, as Jeremie was working on virtualizing Odd, Ulrich and Yumi, Yumi quickly jumped out of her scanner as it closed.
"Strange. Yumi isn't virtualizing. You check what's up. I'll take care of things here." Miu said.
"Sure." Jeremie said going down. "Hey Yumi...what are you…" he said seeing her taking apart a scanner before moving and knocking him out.
"Odd, Ulrich. I'm afraid you guys are on your own here. Rendezvous with Aelita and free Yumi." Miu said.
"What about you? You're gonna be alone with her." Ulrich said.
"Don't worry. I'll be fine." Miu said."Now then…" she said heading down to see Yumi unplugging another scanner. "The game's over, faker."
"Grr." the fake Yumi growled as the eye of XANA appeared on her forehead.
"Do your worst. I can take it. I've already died once." Miu said.
"Oh...but it won't just be you who dies." the fake Yumi said. "Once your friends fall to the monsters inside...they'll have no way of ever returning to Earth...after I destroy the scanners."
"Yeah right, bitch! You think I'm gonna let you get away with this?!" Miu asked.
"You're just some weak human girl. I'm much more advanced. I can easily eliminate you. But first...I'll just get rid of this last scanner." she said before it opened. "Huh?" she said before the real Yumi slugged her.
"Yumi! You're okay!" Miu said.
"You can thank Aelita and the guys for that. They said you and Jeremie were alone so I decided to take the easy way back." Yumi said.
"Devirtualizing yourself? That's a pretty bold move." Miu said.
"Anyway, thanks for keeping her in check all this time. You get back to the supercomputer so you can launch the Return to the Past. I'll deal with my evil twin." Yumi said.
"Alright. I'll be counting on you." Miu said.
"And FYI, you look like me on a bad day." Yumi said as her fake lunged at her and the two started fighting one another.
Miu took this moment to return to the supercomputer. "Guys, can you hear me?"
"Loud and Clear, Miu!" Odd said. "What's the status on Evil Yumi?"
"The real Yumi is taking care of her." Miu said.
"How's it going?" Ulrich asked.
"Uh…" Miu said looking down to see the evil Yumi quickly overpowering the real one. "I think it's about even."
"We'd better finish this up then." Ulrich said.
Ulrich and Odd fended off the monsters long enough for Aelita to deactivate the tower. Once it was deactivated, the fake Yumi soon faded out of existence as the RTTP was soon launched, returning them to earlier in the day.
"I can't believe that fake was able to fool us so easily." Flamberge said.
"Not really. She may have looked and sounded like the Yumi we know, but she was far from perfect." Hiyoko said.
"Although...XANA ended up helping us unintentionally." Yaoyorozu said. "He proved materialization of a virtual being is possible."
"Yes. And that only serves as fuel for Jeremie's program." Francisca said.
"I'm just glad nobody was fooled by that Fake Yumi." Hope said.
"As soon as we noticed her unusual behaviors, there wasn't a doubt in our minds that XANA created a copy of Yumi." Shuichi said.
"Even I wasn't fooled, not even when it tried to flirt with me." Jeremie added.
"Uh huh...sure you weren't." Pit said as the rest of the group laughed.