I don't own Harry Potter or Code Lyoko. I do plan to do evolution.

Is there anyone out there?

"A horrible tragedy may explain the rumour that there's a ghost somewhere at the Kadic Academy. Back in 1905, while the building was under construction, one of the workers, Leon Courbet, is said to have been buried alive under the foundations! In the boiler room area, to be precise," read Sissi from the paper. Harry rolled his eyes.

"It's probably just a tale."

"Get real," said Herb as he glared at Harry. The bell rang.

Class

"Emily, 77. Good work. Jean, 87. Very good. Elisabeth…a quadrilateral is not a quadrant you do later. Ten," said Ms Meyer as Sissi glared at her. "Jeremy, I deducted two points for the ketchup stain on your diagram. 98! Harry, 100. Excellent. Ulrich, you did well. 89. Herb. 93. Excellent. Not as good as Jeremy and harry but excelled."

Ulrich received a message and opened it. "Meet me in the boiler room at midnight. Nicholas."

He looked at Sissi who shrugged. "I didn't organise it. Herb badgered me into doing it."

Later

"May I remind you that in the evening, girls and boys are prohibited from straying for their respective floors. Ok, for any of you who might be thinking of trying to pull anything, remember that the floors are different from each other in that they are either upstairs from or downstairs from the one…above!" rambled Jim as he patrolled the corridor. "Girls are upstairs, and boys downstairs! Comings and goings from upstairs to downstairs and from downstairs to upstairs are strictly forbidden. And if I ever catch anyone from downstairs upstairs or anyone going from upstairs to downstairs, he or she's really going to regret it stairs! You've been warned!"

That night

Ulrich woke up and slipped out of his dorm. He knocked on the boiler door.

"Password?" asked Herb.

"You didn't give me one," said Ulrich after he glanced around.

"Correct. Come in."

"Isn't this a bit square for you?" asked Ulrich as he saw the décor.

"It's not a square, it's a tepogram!" corrected Sissi.

"Pentagram," corrected Herb.

"Oh whatever! Thanks to this and my psychic powers, I'm going to conjure up the spirit of that poor Leon Courbet! I'm sure if we communicate with him he can finally rest in peace," said Sissi, "I'd much rather be with your brother."

"I can't wait to see this!" muttered Ulrich. "Are you taking Lyoko a bit far?"

"Ok, now stand inside the pentagon with me. We will bring together our Ping and Pong energy, and summon up the dead man's ghost," said Sissi. There was muffled laughter.

"You know what?" asked Ulrich. "I think you forgot the paddles! And I think you're talking about Yin and Yang."

"And now let the ceremony begin."

"De profundis tenebrae! De profundis tenebrae! De profundis tenebrae! De profundis tenebrae! De profundis tenebrae!" chanted Herb and Nicholas.

"I summon you, Leon Courbet"

The boiler sparked.

"Yes Leon? I'm listening!"

A form made of smoke came from the boiler. Herb and Nicholas ran away.

"Don't step out of the pentathlon, Ulrich! It protects us! Uh…Leon…Courbet?" asked Sissi as the spectre fled. "Darn it, he's gone, he doesn't want to speak to me!"

"That was one of Xana's spectres Sissi," said Ulrich. "We have a problem."

"We do," agreed Harry. "Xana's activated a tower."

The spectre reappeared and Harry threw shuriken at it. He then pulled Sissi out of the room and closed the door. Ulrich moved the lockers in front of it.

"We need to get to the factory."

Dorms

"I swear, it's true," said Nicholas.

"Come on, you two, calm down," said Jim.

"The ghost of Leon Courbet came after us in the boiler room, Jim!" exclaimed Herb.

"If anyone's after you two, it's a gym teacher in a tracksuit holding a red pen, which he's going to use to give you four hours of detention!"

The spectre slipped out of the room as Harry lead them to his dorm. He shook Jeremy awake.

"Xana's attacking," he said as Jeremy looked at him groggily.

"Laptop."

Ulrich grabbed it and handed it over to Jeremy.

"We'll see in a minute." The scan came up with nothing. "No activated tower."

"Looks like we have a real ghost on our hands," said Ulrich.

Harry frowned. "He's active all right. I can feel him."

"What?" asked Sissi.

"Harry has psychic powers," said Ulrich. "But they only pick up our friend Xana."

Corridor

Jim patrolled the corridor as the spectre snuck up on him. He heard a noise.

"Someone around here is going to be in real trouble!" yelled Jim as he looked around for the source of the noise. He got yanked up as Ulrich, Jeremy, Harry and Sissi ran through the doors. Odd ran out of his room.

"Definitely Xana," said Harry. "No one can do things like he can."

Jim dropped to the ground.

"You ok Jim?" asked Odd.

"Yeah, I'm alright."

"What's that noise?" asked Ulrich as they heard it.

"I don't know but it's getting closer," said Odd. "Harry, can you see anything?"

"Yep. A spectre. Xana can't hide from me! I suggest we run."

The spectre grabbed Odd. Harry threw shuriken at it. It flickered. Jeremy hit it with a fire extinguisher.

"You saw right, the monster depixellised when I hit it," said Jeremy as he looked at the spot where the spectre had been occupying.

"It's gotta be one of Xana's," said Odd.

"Well, duh."

"Why didn't the Superscan pick it up?" asked Ulrich.

"I would guess that Xana bugged it up," said Harry. "He doesn't want us deactivating it after all. Let's head to the factory."

"Let's get Aelita," said Jeremy as they ran off.

Yumi's house

Yumi's phone rang. "Hello?"

"It's me," said Ulrich as Jeremy entered Aelita's room. "There's an emergency. Meet at the factory."

"Got it."

"Jeremy?" asked Aelita as she woke.

"Aelita. Xana's attacking."

The spectre grabbed Jeremy and lifted him up. Harry attacked it again. Jeremy slammed to the floor.

"I think we need to go back in time after this."

"This is no time to hang around," said Ulrich.

They ran out to the manhole and climbed into the sewers.

"Hurry. It's coming."

Harry jumped down and landed on his feet.

"Show off," muttered Odd. Ulrich replaced the cover and they rode through the sewers. Harry groaned when he saw who was waiting for them at the other end.

"You must come with me."

"Sorry, I've got more important things to do," said Harry as he pushed past the old man who turned to look at him. "Like deactivate a tower."

"I've have talked to your parents," continued Dumbledore as Harry watched him. "They have given me permission to take you to Hogwarts."

Harry chuckled then started to laugh fully. "Liar."

The two students glared at him.

"What?" asked Dumbledore.

"You're lying. I can see it in your body language."

"You must be trained Harry. For your safety and others."

"Do you mean locked up in a prison for nine months?" asked Harry.

"Hogwarts is the best school in the Wizarding world," said Hermione pompously. Harry snorted.

"I think this is the best school. I have friends here who don't care for my name. Besides, the auror department here in France took note of your arrival and warned me, seeing as you have been found near me several times, charged with attempted kidnaping and I am a celebratory so they would keep an eye on me."

The group headed into the factory as the three stared at them. Harry waved his hand and they disappeared back to Hogwarts.

Factory

"What took you so long?" asked Yumi as they entered.

"Xana's attacking us, but the Superscan didn't detect anything," explained Jeremy.

"Do you believe in ghosts?" asked Ulrich.

"No!"

"Wrong answer," said Ulrich with a grin. "There's an invisible spectre around. The good thing is that Harry can see it."

"That spectre was creepy," said Sissi as she shuddered. "Is that what you deal with?"

"Hey, that's weird! Xana's managed to corrupt the Superscan! There's an activated tower, but it can't detect it," said Jeremy as he checked it. "Harry, did you add a new vehicle?"

"Yep."

"What do we do now?" asked Ulrich.

"Harry, get to sector five and try to fix the Superscan."

Harry nodded.

"The spectre will strike again soon," said Ulrich. "I'm staying here."

"And I'm going where Harry goes," said Sissi. "Don't try to stop me Harry."

"Sector Five is dangerous."

"As opposed to what? A computer virus attacking everyone?"

"Well, ok. I'll transfer you first then do the others."

Harry and Sissi ran down to the scanners.

"Transfer Harry. Transfer Sissi. Scanner Harry. Scanner Sissi. Virtualisation!"

Harry and Sissi appeared in the forest sector.

"Head west to the edge of the sector."

They ran off while Jeremy virtualised the other three to the desert.

"Whoa, nice to see you without your pyjamas on," said Yumi as she looked at Aelita.

"Hm, nice of you to notice," said Odd. "Jeremy, we're going to need a-"

The Overboard materialised at his feet as the Overwing appeared next to Yumi.

"Ok, forget it!" said Odd then turned to the girls. "Later!"

They separated, Odd covering the desert and the girls going to the mountain sector.

Forest

The two stopped as they reached the edge of the sector.

"Now what?" asked Sissi as she looked around.

"Jeremy, can you summon the transporter?" asked Harry. "Sissi, when we get there, we'll have to be careful. We need to hit a key that will stop a countdown."

"That doesn't sound dangerous," said Sissi.

"I'm entering the code," said Jeremy as he typed Scipio into the computer.

"The area is filled with traps and Creepers," continued Harry. "And not to mention the Scyphozoa."

He shuddered.

"The what?" asked Sissi.

"It's like a big jellyfish that Xana uses to attempt to possess me and take Aelita's memory."

The transporter scooped them up.

Sector Five

Sissi groaned as she looked around.

"Yeah, it made me feel like throwing the first time too. Though that may have something to do with me being unconscious while doing it. No references."

The entrance opened.

"The countdown has started," said Jeremy as the computer started the countdown. "Remember, you only have three minutes."

They ran through the entrance to the main part of sector five.

Lab

"Jeremy…"

The spectre slipped through the roof and headed straight for them.

"What do we do?"

"Come on." Ulrich ran off and Jeremy followed him.

"We can't shake him! There's no point running, he'll catch us every time," said Jeremy as they ran next to the water.

"You got a better idea?" asked Ulrich. They hid in the locker room and the spectre entered. Jeremy yelled.

"I wouldn't mind a little help right now!"

Ulrich passed an electric current through it and it attacked him before backing away.

"He was a tough one."

"Let's get back to the lab," said Jeremy. "The others might need us."

Desert

"The desert looks normal. I'll go to another sector."

Odd flew to the way tower and came out in the forest.

"Darn it, still no activated tower!"

Sector Five

Harry and Sissi ran down the corridor.

"What is Jeremy up to?" wondered Harry as he looked up. "He should have told us where the key is by now."

"Is that the key?" asked Sissi as she pointed at it. Harry glanced at it and grinned.

"Nice going Sissi."

They ran across part of the room when Harry stopped. Sissi shot a look at him.

"Too good to be true!"

The floor started to rearrange itself.

"Sissi, do you think you can fly over there and press it?"

Sissi flapped her wings a few times and lifted off. Harry did the same as the floor totally disappeared.

"How did you do that?" asked Sissi as she stared at his wings. They were total black compared to Sissi's pink.

"I accidently copied them off you when you devirtualised. I don't mean to do it but I can't help it. Jeremy, how much time do we have?"

"This is getting creepy," said Sissi as she saw a creeper. Harry shot at it with laser arrows and it blew up.

They flew over to the key and Sissi pressed it. The floor reappeared and the exit revealed itself. They landed and walked through it.

Mountain sector

"Oh, I must be jinxed," muttered Yumi as she missed a hornet.

"Don't worry," said Aelita as she hit one. "We'll be alright."

Yumi hit another one as they checked the last tower in the sector.

"Let's go to the ice sector."

Sector five

They ran out to the outside and waited for the elevator. Harry pulled Sissi onto it.

"This is fast!"

"I know!"

It stopped and they jogged to the interface. Harry touched and began work.

"I hope Jeremy gets back soon. He'll be able to open the tunnel out of here. Keep an eye out for mantas."

He found the right program and started to debug it. Sissi looked around before hearing a screech.

"What was that?"

"It sounded like… a Scyphozoa! It's not good news."

Harry speed up.

Ice Sector

"Where there's smoke…!" muttered Odd as he saw the tarantula. He followed it as he rode along the walls. The monster led him straight to the tower.

"Jeremy, I found the tower!" The tarantula fired at him and he dodged them. Odd flew around the tower as the monster continued to fire. It hit his tail and it burst into flames. Odd quickly put it out as another one appeared. "Jeremy? What's going on?"

Odd was hit and devirtualised as Aelita and Yumi arrived.

Factory

The spectre picked Jeremy up.

"Don't panic! I'll get you out of there!"

Ulrich kicked the Spectre. Nothing happened.

Sector Five

"And done," said Harry as he closed the terminal. Sissi backed into him. "What's wrong? Oh."

The Scyphozoa approached.

"Help meee!"

"It's not after you Sissi," said Harry as he pulled up his personal terminal. "It's here for me."

The Overjet appeared.

"Climb in." They jumped in and flew off as the Scyphozoa started to float after them.

"Oh man, how does this thing work?" asked Odd as he heard the conversati0on. He pressed a key at random and a window opened.

"Well, Fritz Huckleberg has done it again! His third straight title what a champ! He's amazing!" said the reporter.

"Wow, he even has TV on his computer!"

"Jeremy?" asked Harry.

"Huh? No, it's not Jeremy, it's Odd!"

"Can you open a tunnel for us?" asked Harry. "We're being chased by a Scyphozoa!"

Several screeches echoed around the area.

"And Mantas!"

"I'd love to but how?"

Harry instructed Odd on how to do it and the tunnel to the Ice sector opened. They flew through it.

"Good going Odd. Where's Jeremy and Ulrich?"

"I don't know. The tower's in the north west of the Ice sector."

Harry changed direction and landed next to the tower just in time to see Aelita run into the tower.

"Did you fix the Superscan?" asked Yumi. Harry nodded.

Aelita rose to the second platform.

Aelita

Code

Lyoko

Factory

Ulrich tried to impale the spectre with a bar but it defected it. The Spectre then attacked Ulrich and lifted him up next to Jeremy. Odd picked up the discarded bar and ran at the Spectre.

"Well, not feeling so cocky now, are we?" asked Odd as it looked at him. Odd was knocked to the ground by the spectre. It disappeared and the two boys fell to the ground.

"You ok, guys?" asked Odd as he stood and jogged over "Say something!"

"Something!" exclaimed Ulrich.

"Hey, no stealing my jokes, ok?"

Lab

"Since we didn't fix the Superscan in Sector 5, we have no choice: we've gotta launch a return in time," said Jeremy as they regrouped next to the computer.

"I did fix the program," pointed out Harry.

"We should still go back. Nicholas, Herb and Jim saw the spectre. Return to the past now!"

The bright light started up and expanded to cover everything.

Boiler room

"And now let the ceremony begin," said Sissi in a repeat of the previous ceremony.

"De profundis tenebrae! De profundis tenebrae! De profundis tenebrae! De profundis tenebrae! De profundis tenebrae!" chanted Herb and Nicholas.

"I summon you, Leon Courbet!"

"Whoooo daaaares call my naaaame?" asked Odd in a scary voice.

"Well…I do!"

"Beat it, Miss Delmaaas! Youuu don't know who you're dealing wiiith! Scraaaaam," said Odd in the same voice.

Sissi's cronies ran away screaming.

"You can come out now," called Ulrich.

"Well, I don't think they're going to try and wake the dead again," said Odd as he appeared.

"I still think it would have been better if I did it," said Harry as he appeared from thin air. "Unlike the rest of humanity, I can disappear at will."

"How did we get back here anyway?" asked Sissi as she looked around. "This already happened."

"That's time travel for you," said Harry as he hugged her. "We do it when necessary. It erases people's memory as well so it acts as a cover for us."

"Why do we remember?"

"The computer sends our memories back."

The boiler door shut.

"On the other hand, this place might really be haunted."

They walked out and Harry pecked Sissi on the check. Sissi sighed.

"I think Herb is jealous of you."

"I noticed. He didn't have a chance though."