Hello people of Fanfiction! This is my second Fanfic and my first crossover. Enjoy! P.S This story takes place during GoF and between TC and BotL.

Chapter 1

Hogwarts

Dumbledore sat in his office stroking his phoenix Forkes, wandering what to do about the new revelation that had come to his attention. No one would ever have guessed what was happening. Boy, was Harry Potter in for a surprise. Everyone had thought he was dead- Sirius, Lupin, Dumbledore- and Harry didn't even know about him. Dumbledore took time to remember the true story...

*Flashback*

The Potters sat in their chairs, each cradling a baby. In Lilly's arm was Harry James Potter and in James' was James Sirius Potter, or James junior. Despite being born non-identical twins, they looked the same. The same black unruly hair, the same emerald eyes. They were born just a few months before on July 31st whilst their parents were still in hiding. Lilly was just about to go to sleep when they heard cackling laughter from outside and then the door was blown clean off of its hinges. Lilly and James were up in a flash, wands in one hand and a baby held protectively in the other. When they saw who was at the door, they knew someone had betrayed them. It was Voldemort.

Knowing what was to come, James thrust his son towards Lilly saying, "Take them upstairs, I'll be fine don't worry! Just keep them safe!"

His wife nodded in affirmation and tucked he wand back in her pocket before running up the stairs and putting her sons in their cribs inside the Nursery. That was when the first drop of blood was spilt.

"You won't harm them!" Lilly heard James say.

"Avadakedarva!" And then there was silence.

Lilly mourned for her lost lover but had little time to think as the Dark Lord was soon upon her. She stood arms outstretched in front of the children. Voldemort looked behind her and tutted.

"Naughty Lilly, shouldn't have even conceived them. . And then for you to put up this feeble resistance? Such a shame to waist such fine wizarding blood."

She knew it was the end. She saw him raise his wand and prayed to her friend Lord Poseidon to keep her sons safe. That was the last thing she would ever do.

The Lord stepped over her lifeless body, his face expressionless. He walked straight up to twins and let out a slight smirk.

"Well, well, the Potter parade comes to an end here little ones." He raised his phoenix-feather wand and let loose his curse at Harry and James Jr.

"Avadakedarva!" But to his surprise, the spell rebounded and hit him square in the chest.

All that was left was two crying infants staring at their mothers corpse with identical thunderbolt scars on their heads.

All of a sudden a green light emanated throughout the room and when it vanished stood a tall man with sea-green eyes.

He knelt down by Lilly's body and a silent tear slid down his normally humorous face.

"I'm sorry Lilly, I couldn't get her equick enough." He composed himself before facing the infants.

"Well little ones, I'm terribly sorry but I can only bring one of you to America. My lover Sally Jackson can only take one of you." He chose. He placed a light kiss on Harrys head and picked up little James. He gave one last pitying glance at the other infant and in a flash was gone.

And so Harry was left crying in his nursery room until a man in long silky robes with a white, long wispy beard discovered him. He only assumed after seeing the Potters dead bodies that the infant was dead also.

*End Flashback*

And so it was believed to this day. No-one knew about the other boy. The only evidence he was ever alive was the small engraved tombstone in Godricks Hollow with the words:

James Sirius Potter

Beloved son and brother

Born 31st July Died December 1st

May you rest in peace.

But know the wise wizard knew the truth, and would find the boy as soon as possible. Recent leads had revealed that James Potter Jr was adopted by a kind woman in New York. Also, he was blessed by Poseidon when he got to America and thus was believed to be a demi-god- but it wasn't right. James should not be raised as a lowly demi-god, and Dumbledore was determined to train the young wizard properly in the ways of a wizard, even if he had to tear the child away from all he ever knew. He needed to reunite him with his brother Harry, and planned to do just that. It was decided. He quickly got his owl and sent a letter to Sirius. He had a right to know that his other God son lived. They were going to get James back one way or another. He got a drachma out of his hidden pouch of foreign currencies, and IM'd Chiron, the boys trainer. If you hadn't already guessed, Percy Jackson was in a lot of trouble.

Ta da! How was that? PLease Review, Favourite and Follow this if you want me to continue! Peace Out! P.S My other story is being put on hold for now.