This is from Harry's 4th year, and after the war with Gaea for Percy Jackson

Disclaimer: I do not own Percy Jackson or Harry Potter and their characters/storylines

PERCY POV

I was sitting in my cabin mentally talking to my new pet fish (And yes, I know how weird that sounds, just don't ask) when an extremely hassled Nico di Angelo showed up. "Chiron wants to see you in the Big House," he said, and left.

"Nice to see you too," I grumbled, rolling my eyes, and stumbled out into the sunshine. I made my way past the cabins to the Big House. Chiron (in wheelchair mode) and Nico were sitting on the porch waiting for me. I went up to the two and asked, "So why are we here again?"

Nico opened his mouth but Chiron got there first. "Nico was taking care of some left behind souls when he got word of a rather large platoon of monsters in London."

"So you want us to go and kick some monster butt?" I clarified. Chiron frowned a my choice of words but nodded. "Well," I said. "What kind of monsters are there?"

Nico shrugged. "No idea," he said. "Let's go find out." He raised his eyebrows at Chiron who nodded, then he grabbed my hand and we melted into the shadows. We were flying through, er, I guess the shadows going at breakneck speed, faster than I've ever gone before and was praying to all the gods I knew Nico knew what he was doing when we hit something. Hard. We plummeted down. I was screaming and I was pretty sure Nico was too.

"What the Hades is happening!" I yelled.

"I think..." Nico began before we hit the ground. Again, hard. We were lying under a tree, close to a lake. It was evening, and I could see a large castle near us. I stared in awe at the thing before I realized I was slowly passing out. I registered Nico was out too right before everything went black.

HARRY'S POV

I was waiting in the Great Hall. All the houses were buzzing excitedly. I let out a groan as I spotted Umbridge at the teacher table. I could tell this was defiantly not going to be an easy year.

"What's wrong, Harry?" Ron asked, chewing on a treacle tart.

I sighed and pointed at Umbridge, who was wearing a nasty pink sweater and a brooch. Ron caught sight of her and frowned. "That's the weird Umbridge lady, right?" he said, swallowing a piece of the tart. I nodded.

The rest of the night passed without event. The prefects led us up to the dormitories and told us the password. I stumbled into my bed and fell asleep into (thankfully) dreamless sleep.

*TIME SKIP TO MORNING*

I woke the next morning to the chirping birds outside. I sighed in relief it was a Saturday. We wouldn't have to worry about homework until Monday. Well, at least, new home work.

I woke up Ron and we headed down to the common room, where Hermione was waiting for us. When she saw we were up she said, "Why don't we go down to the lake? Then we can study, get ready for classes...Oh come on you two," she added as she spotted our exasperated faces at the mention of 'study'.

She stalked out of the common room, me and Ron following her, and headed down to the lake. It looked really peaceful. "You're right, 'Mione. It's nice here."

"Hey, what's that?" Ron asked, pointing to a tree near the lake.

I couldn't see anything. I shrugged. "Oh, come on, I'm not stupid," Ron said. Hermione snorted at that until Ron dragged me and Hermione down to the tree.

When we got closer, we saw a black lump. When we finally saw what it was I let out a very manly yelp. There were two teenagers unconscious on the ground. One looked about sixteen or seventeen, with dark messy hair and a sea green shirt.

The other one was wearing black. He looked about fourteen and had on a skull ring and dark hair, and really pale skin. The second I saw him my scar throbbed. "Ouch!"

Hermione looked at me in concern. "What is it, Harry?"

I just shook my head. "My scar...Hermione, go get Dumbledore. He'll know who they are." I sounded more confident than I felt. I had never seen them before at Hogwarts. Soon I saw Dumbledore rushing out his robes flying out behind him. He levitated the two boys and gestured for us to follow him to the Hospital Wing.

NICO POV

I felt terrible. My head felt like it was going to explode or something. I cracked open my eye. I could see I was in a white room probably a hospital or something. I cursed all the white in my head before realizing (A), Percy was in a bed next to me, sleeping and (B), there were three teenagers watching me.

They were all wearing black bathrobes or something, with a red and gold emblem on it. One had brown bushy hair and large front teeth, one had freckles and red hair, and the third had dark hair, glasses, and a lightning scar that immediately reminded me of Zeus. Unfortunately. I have bad expiriences with gods.

"Do you need something?" I asked sarcastically. The bushy haired one looked shocked and the red haired one looked like he wanted to laugh.

Suddenly, Percy fell of the bed, yelled in surprise, and had his pen in his hand (thankfully not in sword mode) before realizing what happened. He started looking around the room in awe.

"Where are we?" He asked.

"Hogwarts, of course," a voice said next to me, startling me so much I almost fell of the bed too.

I turned and found an old man with twinkly eyes, long silver hair and odd robes. "Would you mind telling me who you are?"

"Peter Johnson," Percy answered as I said, "Who are you?"

"Professor Dumbledore, head master of this school," he paused, then added, "I'm afraid you are not safe here. The Ministry of Magic wants to feed you Vertisuem."

"What's that?" Percy asked, looking revolted.

Dumbledore sighed, and told us about the Ministry and Vertisuem, which turned out to be a truth potion. He ended by telling us where we were, in London.

"Yes!" I yelled. "I told you I got us to the right place, Per-Peter!"

Dumbledore stood up. "I would like to ask you who you are, one more time," he said softly.

I looked at Percy. "We will tell you, privately." I said, looking pointedly at the trio.

Ron and Harry shurgged, but the bushy haired one looked shocked and kind of angry. She spun on her heel and left, but I could see the other two looking at me suspiciously. Great.

Dumbledore sat on a chair between my bed and Percy's.

I took a deep breath. Something told me I had to tell Dumbledore. I was about to tell the old man about the gods when a voice echoed in my head.

Hello, Nico.

I jumped literally a foot in the air. "What was that!" I yelled.

"What?" Percy asked, looking concerned.

"I heard a voice. It sounded like my father's!" I held up a finger and tried to see if the voice would come back.

Hello?

Ah, Nico. I reached you, good.

Right, father. What am I doing here? Something affected my shadow traveling.

Er, yes. Hecate decided to send you to her pet world with my consent.

Pet world? And why did you say yes?

Pet world as in wizards,boy. To save them. And I need you and Jackson to kil Tom Riddle.

I gasped. "Tom Riddle's here!" I said.

Dumbledore looked shocked. "How did you know that?" he asked.

"And you are wizards! Look, Dumbledore, my father just contacted me. Him and my aunt sent us here to kill Tom Riddle."

And Harry Potter. My father said. I wish it were otherwise, and Hecate does too, but I cannot permit him to escape death like he did about sixteen years ago.

"And Harry Potter," I said. Dumbledore's eyes widened.

"You can't!" he said. "Only Harry Potter can have the power to kill Voldemort. I can't let this happen!"

"First of all, I have too. Second, who is this Moldyvart? Third, I can wait until after Tom is dead to kill Potter. Oh, and who is Potter anyway?"

Dumbledore explained to us about Tom/Voldemort, hocruxes, and that Harry was the glasses boy.

Nico, attend the school. It is apparently vital to the mission. And Dumbledore knows about the gods. Hades hesitated. Good luck.

"Dumbledore, who is your father?" I asked. Percy looked slightly shocked and confused. "Tell us. Mine is Hades."

Percy looked confused so I filled him in then looked expectantly at Dumbledore. He sighed for a moment, then said, "It's my mother. Minerva. Why do you use Greek names?"

"We're Greek demigods." Percy and I filled him in on Gaea and the war. He had been really out of date, apparently.

Suddenly, a new voice popped into my head. Hello! This is Hecate. I hope you succeed! And by the way, I'm blessing you with magic. Bye!

The second she left, I felt...powerful, kind of. At the same time, a trunk popped into existence. Right on my foot. I yelled in pain and grabbed my foot.

At the same time, I could tell Hecate had popped into Percy's head as well because he had an awestruck expression on his face, as well as a wooden trunk by his feet. Mine was black. I carefully peeked into it.

Inside, I found a black velvet case, robes, a box of feathers, some rusted looking paper, and books. Lots of them. I opened the velvet box. In it was a stick. I saw Percy looking at one too.

I bit back a laugh. It was a STICK! A note was attached to my stick. It read:

This is your wand. Made out of a Fury's hair and aspodel tree.

-Hecate

I walked over to Percy's. It was apparently made out of drift wood and shark teeth.

Dumbledore looked at Percy's also. "Neptune-er Poseidon?" Percy nodded.

"Well, looks like we'll be staying." I said.

"Dumbledore nodded, but he looked a bit dazed. "I'l introduce you at the feast. Today is the first day at Hogwarts, so you can be sorted with the first years. Don't reveal who you are to anyone. Especially you, Nico, is it? Anyway, the Golden Trio is Harry, Ron, and Hermione. They are a tad nosy. And, Nico, if there is any way to change your father's mind about Harry..."

He trailed off and left the room, geustering for us to him. We did, and he led us through like, fifty thousand corridors before we finally emerged in a large room behind Dumbledore.

The room had five tables, one with what I guessed were teachers and the others had kids on them. Each table had a colors scheme: red and gold, silver and green, silver and blue, and yellow and black.

Scanning over the room, I saw some familiar friends. Draco, son of Mercury, Neville, son of Ceres, and Luna, daughter of Athena. I wanted to wave, until I saw bushy hair-sorry, Hermione, Ron, and Harry looking at us suspiciously. Or, Hermione and Harry were. Ron was staring at his gold plate hungrily.

Dumbledore walked to the staff table.

"To our newcomers, welcome! To our old hands, welcome back! A slight change has been made to our student population. I would like to welcome Percy Jackson and Nico di Angelo to Hogwarts!"

An excited murmuring broke out, escpecially among our good friends the Golden Trio, as Dumbledore called them. Except their murmuring was more suspicious and worried.

Anyway, an old lady came through the doors leading a bunch of eleven year olds. She came and placed a frayed hat on a stool. Looking around, I realized that the eleven year olds were new to Hogwarts and this probably was a common occurance as the kids at the tables looked bored.

Then, something happened I most definetly did NOT expect.

PERCY POV

The hat began to sing. No, I'm not kidding. And no, I did most definetly not erupt into laughter while the song was going in the middle of a magical school for wizards. Ha, no. That would be stupid. Well, there is a reason Annabeth calls me sea weed brain, right?

Anyways, so I started laughing, causing the hat to pause and Nico to kick me in the shin. Hard.