Ashfall series (Pittacus Lore)

We have waited generations for you... Syd Chambers knows that there's life on other planets because he's descended from it. His father was from a distant world called Denza and has been missing--presumed dead--for years. When Syd discovers a device his father left behind that shows not only that he's alive, but where he is, Syd must set out on a mission of his own. But along the way, he discovers a deadly, unbearable secret that could destroy Denza,...