It was another morning in Kadic as the younger School Group were currently heading to breakfast as they saw Aelita and the girls exiting the dorms.

"Hey there, ladies. Einstein isn't with you?" Odd asked.

"No, we haven't seen him all day." Leonora said.

"Speak of the devil, look who's here." Simon said as they saw Jeremy with a keyboard imprint on his head running up to them.

"Let me guess, you fell asleep at your desk again." Francisca said.

"Yeah, how'd you know?" Jeremie asked.

"There's an imprint of a keyboard on your head." Mari said as the group shared a laugh.

"I was up all night working on a program. I came up with an idea for bringing William back." Jeremie said.

"Hey Ulrich, incoming." Simon said as the group saw Hiroki approaching.

"I got this. I'll see you guys at breakfast." Ulrich said.

The group nodded and left Ulrich to talk it out with Hiroki.

"Ulrich, you're good with the girls, right?" Hiroki asked.

"Depends on the girl." Ulrich said.

"My sister." Hiroki said.

"Beep. We're good friends. That's all." Ulrich said.

"Yeah, that's what you say. Listen…I like this one girl..Milly." Hiroki said.

"Oh…that Milly. She's got a passion for journalism. Find her some sort of interesting news." Ulrich said.

"Oh…that shouldn't be too hard." Hiroki said.

Ulrich soon returned to the dining hall with the group.

"So, what did Hiroki want to talk about?" Petra asked.

"Romantic advice. Kid's got a crush on Milly." Ulrich said.

"Really?" Simon asked. "Though isn't he a bit young for her?"

"Not really, he's just small for his age." Aelita said. "He actually skipped a grade, if I remember right."

"Huh, talk about a boy genius." Al said.

"So, what's this program you were talking about, Jeremie?" Ginseng asked.

"Well, whenever a person is virtualized, they admit a binary residue." Jeremie started. "It's like an emanation of the physical form that is resequenced into a digital format."

"Basically, they leave a sort of essence behind." Al said.

"Basically." Jeremie confirmed. "Anyway, if I use William's DNA sequence, we can look for him every time we enter Lyoko and search the sea for where he is."

"So the Skid will be a sniffer sub." Odd said.

"In a manner of speaking…" Jeremie said. "Since we're class free this afternoon, I say we try it out then."

As they were heading out, some of the group saw Hiroki run by before bumping into them, before dropping something and running from Yumi.

"What was that about?" Izuku asked as he picked up the book. "Any of yours?"

"A dark book with a flower is not my style." Odd said.

"Hey, since Hiroki was running from Yumi, maybe it belongs to her." Ethox suggested.

"Meaning…Ah! This is her diary!" Izuku realized.

"We better give it back to her." Saki said.

"Are you kidding? If she sees us with this, she'll jump to the worst conclusion and kill Hiroki. Or worse, us." Kazuma said.

"Well you got a better idea, panty thief?" Saki asked.

"Look…we can play this cool. We'll hide the diary somewhere in the woods. Pretend to help Yumi look for it and then she finds it. No one dies." Subaru said.

"That sounds like it could backfire…" Ethox said.

"Lives are on the line here, Ethox. We have no time for second-guessing." Kazuma said. "C'mon, let's go."

The group then got to work.

"Okay. We hid the diary under a pile of leaves. Easy to find." Odd said.

"All right. Here we go." Kazuma said as they saw Ulrich and Hiroki leading Yumi into the woods as they got close to a pile of leaves. "We're all getting out of this one alive."

"Being a little dramatic there, don't you think?" Mark asked.

"A girl's diary is a precious thing. They mean more than life." Subaru said.

Soon enough, the diary had been dug up. But upon opening it, all the pages inside were gone.

"Ah!" Yumi gasped as she glared at Hiroki.

"What did you guys do?" Theo whispered.

"We didn't do anything! All the pages were there when we hid it." Subaru whispered back.

"I'll never forgive you for this, Hiroki." Yumi said before she walked away.

"Oh no…" Ethox said in distress. "We really screwed up."

The group later went to the factory as the next Skid operation was soon well underway.

"Alright, Jeremie's running the program now. Standby." Hermit said before an alert went off.

"I know that sound, that's the 'something really bad is happening' sound!" Mark said.

"Duh, no kidding." Simon said.

"The program has caused a system error. The Skid's sonar is bugged up." 9S said.

"Mission's too dangerous without sonar. Return to dry dock." Sachiko said.

Just then the digital sea turned red.

"Might wanna hold off…I'm seeing 3 Kongers coming after you guys." Jeremie said.

"Deploying Nav Skids." Aelita said, deploying the Nav Skids.

The Nav Skids fought off the three Kongers before Aelita called them back.

"Recovery." Aelita said as the Nav Skids docked back in, except there was one missing. "Where's Yumi?"

"What? She was dealing with that first Konger no problem last I saw!" Mark exclaimed. "Don't tell me she's…"

"I don't think so, there's no record of her being devirtualized." Jeremie said.

"That means she's still somewhere onboard her Nav Skid, somewhere in the middle of the Digital Sea." Aelita said.

"You all need to come back so I can run a repair program." Jeremie said.

"What?!" Ulrich said.

"We don't have much choice." Aelita said as they returned to the dry dock and returned to Earth.

"Ugh…This sucks." Kazuma said as some of the group were in the woods.

"I know…Yumi may be gone forever." Theo said.

"Yeah…she could be…" Subaru said as he saw Kiwi carrying something. "Hey, what you got…" he said before looking shocked. "This…this is the diary!"

"What? No way." Kazuma said as he looked at it. "Oh my god, it is! Odd's Diggity-Dog dumped it here!"

"I get it. When Kiwi saw us burying it, he must have thought we were playing a game, so he dug up the pages and buried them here." Subaru said.

"Well we have the diary…now we just need Yumi." Theo said.

"Damn it…" Ethox said, looking down. "We caused Yumi to disown Hiroki, and now this happens… we're the worst."

"Hey, hey, now's not the time to be hard on ourselves." Mark said. "We'll find Yumi and make sure she and Hiroki can make up."

"Mark's right." Ulrich spoke up. "There's no way Yumi would go out like that. We'll…we'll bring her home." he said softly before his phone rang. "Hello, Aelita?! Okay, we're on our way."

Ulrich hung up and turned towards the rest of the group with a smile. "They found Yumi!"

"Then what the heck are we waiting for?!" Ethox said, jumping up. "Let's go!" he declared as the group raced to the factory.

It wasn't long before they got back into the Skid and went after Yumi who was being pursued by a Konger as well as William in a dark sub known as a Rorkal.

"Heh…I have you now. Fire!" William said, firing torpedos at Yumi before the Skid blocked with its shields. "Oh great, perfect timing, guys."

"Hey, William! Nice sub you got there!" Mark said.

"Thanks, XANA based it off your Skid's design." William said. "Here, let me show you the weapon systems!" he said as he fired more torpedos at them.

"Deploying Nav Skids." Aelita said as she sent out the other Nav Skids as they avoided the shots.

"We'll come to play." Ulrich said as they battled with William.

"Won't be saying that after I sink you." William said as he chased Ulrich.

However, Odd acted as a diversion for William before Ulrich shot him from behind.

"Oh, come on!" William called out before his sub broke apart as he vanished as the sea turned calm and blue.

"Phew…looks like everyone is coming home." Jeremie sighed.

"Not everyone…" Aelita said. "We'll be back for you soon, William."

They returned to Earth that night, and the boys dropped off the diary on Yumi's bed before heading back.

"There…crisis averted!" Subaru said.

"Good." Theo said. "We repaired her family and no one got hurt."

"Yeah… family is one of the most important things out there." Ethox said. "I'm glad we managed to fix this."

"Great… Now let's agree to never tell Yumi the truth." Kazuma said.

"Agreed." they all said as they headed back to Kadic.