I am Number Four By Pittacus Lore

I am number four is about a planet that has been attacked by evil aliens and they have killed everyone on the planet except for 18 people that escape on a ship to earth. There is a spell that is cast on 9 people on the ship thats makes it so they have to be killed in order from 1-9. The spell only works if the 9 are separated from each other. This story is about number 4. He is in hiding in america and keeps changing his name and is travelling with his teacher as all of the 9 are traveling with there teacher. Each person has a teacher that will help them perfect there magical powers. At a certain age the 9 people get magic powers that they will use to defeat the evil aliens that took there planet.