Hi guys! So I've been wanting to do a crossover for a long time, I think it has a lot of potential. This story will be the first in the Intertwining Magic trilogy.

A few things: It takes place in Harry's fifth year, so Order of the Phoenix time. The giant war has happened, so the demigods have defeated Gaia. I know, the demigods aren't the same age as Harry, but for the sake of this story, I've made them so they are. I know they're really not, but just pretend that they are the same age.

I hope you enjoy this story, and please review!

DISCLAIMER: I don't own the characters, nor the settings. Everything you recognise as canon belong to their respective authors. That applies for the whole story!

Chapter 1-Another Quest

Zeus

"No!" Zeus snarled. "That cannot be allowed to happen! If those two worlds mix… It is bad enough that the Greeks and the Romans are aware of each other's existence. We cannot allow letting the demigods meet…. The wizards."

The 12 Olympian gods had convened for council. Lady Hecate, goddess of magic, stood unflinching before Zeus, wearing an elegant dress of black silk, her dark hair cascading down her pale neck.

"My lord, there is no other way. The dark wizard has risen once again. The Potter boy is our only hope left to defeat them, but he will need help. We must send the heroes of Olympus to help him, or the dark wizard will win," she urged him.

Zeus' nostrils flared. "Why, Hecate, does a simple dark wizard require to gods to get involved."

Hecate's face darkened. "He is not just any dark wizard. He has ancestry which…" Lady Hecate shuddered, and worried glances were exchanged between the gods. Hecate continued. "He threatens the whole society of the wizarding world. If he is allowed to continue, if there is no resistance, not only will the wizards suffer, but it could lead to mass genocide amongst the mortals." Seeing Zeus raise an eyebrow, she continued. "But the gods would not get involved, no. We are just, simply, issuing a quest to the demigods. The only reason the council was called is because I need your permission to reveal the wizards to the demigods."

Artemis nodded. "Father that does seem reasonable."

Poseidon sighed. "As much as I don't want to put my son and his friends back in a war so soon after Gaia has been defeated, I fear that is what we will have to do."

Zeus scowled. "The worlds were not made to be mixed. But we shall have a vote. All in favour of sending the heroes of Olympus to… Hogwarts?"

Zeus frowned as he saw hands rise. He got to his feet. "Fine. Hecate, you will take care of the details. The Heroes of Olympus shall go to the wizarding school and assist Harry Potter to defeat Lord Voldemort."

And with that, the King of Gods stormed out of the chamber.

Percy

Percy closed his eyes, and a wave rose behind him, as high as his shoulders. He brought it crashing down on Annabeth, who was splashing him. He dived under the surface, pushing Annabeth's legs over so she almost collapsed. She wriggled, laughing.

"You're such a cheat, Percy! You always use your powers when we have water fights."

They were having a day on the beach of Camp Half-Blood. It was evening now, the sun setting in the sky, and Percy had begged Annabeth for them to go into the sea. Reluctantly she had agreed, making Percy promise to instantly dry her clothes afterwards. Now they were having a very mature game of splashing each other.

Percy pouted. "Sorry. I can't help it."

Annabeth laughed again. "You're such an idiot, Seaweed Brain." She leapt forward and pushed Percy backwards playfully. He just grinned, and leaned in to kiss her. However they were soon interrupted by a figure approaching them, running across the beach. It was Piper, dressed in jeans and a jacket. She waved her hands.

"Guys! I've been looking all over for you. Meeting in the big house. Now!"

…..

Percy and Annabeth entered the rec room of the big house, holding hands, Piper behind them. Inside Chiron was waiting anxiously, sitting in his wheelchair, Rachel sitting beside him. Jason was slumped on his chair, twiddling his thumbs, and absently minded watching Leo and Calypso. Calypso was telling Leo off for some thing or another. Frank and Hazel were whacking each other with their table tennis paddles. Percy grinned. Yep, these were his friends.

When Chiron spotted Percy, Annabeth and Piper, he smiled, his face wrinkling. "Ah, you're here. Thank you, Piper, for finding them." He gestured for them to sit down. "I'm sure you all want to know why I called you here-" he began gravely, before Leo interrupted him.

"Yeah, too right we do!" Leo punched his fist into the air. Everyone stared at him. Calypso buried her face into her hands.

"Leo, please shut up." Everyone burst out loud laughing at Calypso's comment, as Leo pulled a goofy face, and Calypso slapped him playfully.

Chiron cleared his throat before continuing. "So as I was saying before I was interrupted, I have called you here because the gods need your help again." Before the demigods could speak, he raised his hand. "Let me explain. In the ancient times, when the Greek empire was new and powerful, the Lady Hecate granted a certain group of mortals, with the permission of the Olympian council, magic. This group of blessed people grew, as they had children, and their children had children. Their fame grew wide, and soon stories were told about them. This began the stories of warlocks, of wizards. The group spread round the world, eventually forgetting that the gods had blessed them with magic, losing that link, not knowing there were any gods at all. Only few wizards now know of the gods' existence. The wizard society lives today, now disguised as normal mortals, while most of them live a double life- pretending to be a muggle (what they call mortals) but really being a wizard." Chiron paused, and looked around the room. Incredulity was etched upon everyone's face. Percy spoke up.

"Chiron. Is this a joke? How can there be… wizards?" He asked, trying to get his head round such an idea.

Chiron raised an eyebrow. "You live in a world of gods. You have even met sorcerers and sorceresses. Hazel is one! Is it really so hard to believe?"

Hazel shrugged. "I guess not. So these people, they're just like Circe or Pasiphae? Just sorcerers?"

"No. In fact, they're entirely different. Only few people are sorcerers, and usually that is because Hecate or someone equally powerful has taught them, like you Hazel. They have the ability to manipulate the mist, but that is it. These wizards possess magic in their core, the same way Percy is able to control water, or any of you have your powers."

"So they're like demigods, without the god, but with the power?"

"Well, in a way, but their power can extend to all sorts of different spells. In fact, the particular wizards that are of relevance to you are traditional British wizards. Wands and pointy hats."

Leo snorted. "Wands and pointy hats? Man, I gotta meet these people."

"Well, you will. That is why I am telling you about wizards. No other demigods have ever known- at least, not in recent years. Demigods and wizards have been separated, but now you must meet them. A certain Dark Wizard, by the name of Voldemort, has risen." Chiron began to tell them of this Voldemort, and then how a baby called Harry Potter defeated him, and how last year, Voldemort had come back, using this Harry's blood. This was a lot for Percy, who couldn't help thinking about how Voldemort walked around with such a normal name like that. I mean, that name was bound to get a few stares at Wal-Mart.

"So you must go to the wizarding school, Hogwarts, and help Harry Potter, and his friends Ron Weasley and Hermione Granger. The headmaster, Professor Dumbledore, is a good friend of mine. He knows about the gods, and he knows about you. He will help you settle in."

Annabeth raised an eyebrow. "We were just in a war, surely we don't have to join another one?"

Chiron sighed. "I'm sorry, it is the will of the gods. However, it's not completely a war yet. This is more of a protection mission, like a normal quest."

Annabeth scowled, before standing up. "I need to think about this." Chiron nodded. Annabeth left the room, and Percy immediately followed.

"Hey, Annabeth wait!" He caught up with her. "Annabeth." He put his arm around her, and she rested her head on his shoulder.

"Sorry for that," she muttered. "It's just-"

"I understand Wise Girl. We don't have to go if you don't want to."

"No, we do. This Voldemort, he sounds bad, as bad as Kronos and possibly as dangerous as Gaia. We should help." Her eyes sparkled. "Plus, I've always wanted to visit Britain. It could be fun. I over reacted. We haven't been on a quest for ages, and a school doesn't sound like a very dangerous place. Oh, and we could learn all sorts of things at Hogwarts-" she enthused as Percy laughed. He kissed her, cutting her off.

"Well then, let's go in, and tell the others that we're going to Hogwarts."

So that's the first chapter!

The next chapter will be posted tomorrow, since I have the beginning of this story written out. The next chapter will be from the wizards' perspective.

So there you go, please review! I hope you liked it!