DISCLAMER: - I don't own the Harry Potter or Percy Jackson series. No money is being made from this fanfic. It is just written for fun.

Note:- The chapter has been edited and revised.

Also, Tomarry and Dramione are going to have slow build-up. Percabeth is already going to be canon.

Warning:- Heavy bashing of Jason, Piper and Ron. If you are their fans I would advise you to not read any further.

Chapter 1:- Call from Olympus

Percy's P.O.V:-

Percy Jackson was waiting outside the Empire State Building for his friends to arrive. They all had been called by the Olympians for a supposedly important meeting. Percy glanced at his watch a little impatiently, and then looked up at Tyson, who was busy munching on a packet of chips.

It was Tyson who had came at Percy's home to inform him about this meeting. Percy had immediately packed up his stuff, said a hasty goodbye to his mother and Paul and followed Tyson all the way up to here. He was quite curious to know why the Olympians had decided to keep such an urgent meeting, and was sincerely hoping that this won't mean another stupid prophecy or a dangerous quest for all of them.

"Do you think the others would show up at all?" Percy asked Tyson.

"Yeah, they all have been called," Tyson replied, craning his neck a bit to see if the other demigods had arrived.

"So, did Poseidon tell you about this meeting?" Percy asked him.

"Yes, Daddy is also going to be present over there," Tyson replied excitedly, "And that's why he wanted all of his children to come as well."

Percy stared at Tyson wide-eyed upon hearing this. Because if Poseidon wanted all of his children to come, then obviously a certain raven-haired boy, with emerald eyes, from Britain would be invited as well. It wasn't as if Percy didn't liked him of course, it was just that said boy was a little different. Yes, the demigods from the wizarding world were different from them, but this particular boy was a totally unique and peculiar case.

Just then, he heard loud voices of people talking from behind him, which he recognized very well. He turned around to find Annabeth, Thalia, Jason, Nico, Leo and Piper hurrying towards them.

"Hi Percy! How are you?" Annabeth Chase, his girlfriend, asked him and gave him a tiny peck on his lips.

"I am great, Wise Girl," he replied, kissing her in return.

"So, do you know why we all have been called over here?" Jason asked him.

"Tyson knows I think," Percy replied. They all turned to look at Tyson.

"No, dad only asked me to call everyone over here. He didn't tell me the reason for the meeting," Tyson replied.

"Um, Tyson, have the demigods from Britain been called as well?" Piper asked him, sounding a little nervous.

"So what if they have been called Piper?" Percy asked her in return. He just knew that they all would react like this.

"Well, I don't have any problem with all of them. It's just that, well, Harry…" Piper trailed off, knowing that everyone will understand, what she wanted to say.

"And what exactly is your problem with Harry?" Percy asked her, feeling extremely annoyed. He did not like it when people talked like that about his half-brother.

"Percy, you can't deny the fact that he is a little creepy," Jason said.

"We can discuss this later," Thalia said firmly, "Right now we should hurry up, otherwise father would get seriously angry."

They all were of course well acquainted with Zeus's anger and impatience, hence they hurried up inside the building, and Percy whispered a quick 'Thanks' to Thalia. However, he knew that this was only temporary, and a total chaos was going to take place on his half-brother's arrival.

Harry's P.O.V:-

Harry Potter was currently sitting in the Hogwarts library, going through some rare books on dark magic.

"You know that we aren't allowed to read them, right?" his best-friend, Draco Malfoy, asked him.

Harry looked up from his book and replied, "Yes, I know that Draco. And that's precisely why I have charmed these books. If anyone else other than me tries to read them, they'll think that these are just some old Quidditch magazines."

"How come you are always so thoughtful?" Draco asked, sounding slightly jealous.

"That's because I bother to use my brains, unlike you Draco," Harry replied.

He knew that Draco was smart too, all the Malfoys were. But firstly, Draco was just too lazy to actually use his brains and secondly, he wasn't a Malfoy, not by blood at least.

No, Draco's father was Apollo, a Greek god, which meant that Draco was a half-blood or a demigod. That was one of the reasons why Harry got along so well with him. Harry himself was a half-blood, a son of Poseidon to be precise.

He had been just about an year old when his mother and step-father had been murdered by the dark wizard named Voldemort. His father, Poseidon, had been extremely worried by that incident and had almost planned on sending him to Camp Half-Blood, to ensure his safety. But a certain meddling and manipulative person by the name of Albus Dumbledore had told Poseidon about some blood magic done by Harry's mother Lily.

Hence, Harry had to spend the next ten years of his life with his mother's only remaining relatives, namely the Dursleys, who had treated him in an extremely harsh and cruel manner. He had learnt the first lesson of his life over there, that to defeat the dark you need to become equally dark and powerful. Being a weak and innocent kid had never been an option for him, especially when Dudley and his gang used to chase him.

Harry had found his first true home at Hogwarts, where he had become friends with all of his house-mates, like Draco, Blaise, Pansy and the others. He had also visited Camp Half-Blood a couple of times, and met his half-brothers and cousins over there. But Harry had a feeling that they didn't liked him much, perhaps it was because of his overall dark and mysterious personality, but most of the demigods at the camp usually chose to avoid him.

He was brought out from his thoughts, as he heard Draco's voice, "Harry look! It's Weasley and Granger!"

Harry turned around to see Weasley and Granger walking briskly towards their table. Ronald Weasley was a son of Hermes, whereas Hermione Granger was a daughter of Athena. But since the two of them were in the Gryffindor house, there relations with Harry and Draco were usually hostile.

"What?" Harry asked them, as they came near their table.

"My father has sent me a message," Weasley told him, sounding quite serious for once, "The Gods have kept an urgent meeting on Olympus, and we all have been asked to come."

"That's great!" Draco whispered to Harry, looking quite excited at the prospect of visiting Olympus.

Harry on the other hand got worried. He knew that if the Gods had kept an urgent meeting it was most probably some serious matter.

"So are we supposed to go to Olympus now?" he asked Weasley and Granger. Both of them nodded.

"But how is that possible?!" Draco exclaimed. "We can't reach Olympus from here, in such a short span of time!"

"You are forgetting something Malfoy," Weasley replied smugly, "My father is a god of travelers, and he has sent me a special portkey which will straightaway transport all of us to Olympus."

He took out a small piece of parchment from his pocket, made sure that no one was watching them and then placed it on the table.

"Alright, everyone, just place one of your fingers on it," Granger instructed them.

So they all placed a finger on the parchment and the next moment it glowed with a bright blue color. The portkey pulled them forward, moving at a great speed and before they knew it, they had been transported straight from the Hogwarts library to the beautiful city of Olympus.

A.N:- Hi everyone! So this was just a random idea that had been in my mind for a long time. As you can see, Harry is in Slytherin house in this story. Also, he would be get to use his potential and his Slytherin side in this fic. And he would be way more interested in dark magic compared to canon.

So please review and tell me what you think about this story and whether it is worth continuing or not.