Prologue:
Keith has always known he was different, ever since the dreams and sickness.
The dreams were about a strange place, a beautiful place. The place had a majestic silver and blue castle and fields upon fields of vibrant violet flowers. Animals, not accustomed to Earth, roamed as many different species played and interacted. He has had them ever since... well... for as long as he could remember.
The sickness is on and off; no one could predict when it would start or when it would end.
The first time Keith remember it happening was his first orphanage, when three older boys decided to teach him his "place". One of them had pulled out a knife and Keith had gotten so afraid. The next thing he knew was a burning pain than nothing. He awoke in the hospital 3 weeks later and was put in another orphanage.
The second time was at the Galaxy Garrison. After Iverson had said the Kerberos Mission had failed and Keith felt pure unbridled rage. A familiar pain began to form in his chest and it spread through his entire body. He awoke in the med-bay, after a week he was discharge and kicked out of the Garrison. Apparently, he had punched Iverson in the eye before he had passed out.
So, he knew he was different. He just didn't expect to be part alien.