When their home planet of Lorien was invaded by the evil Mogadarians, intent on raping the planet of all its natural resources, nine special infants were sent to Earth for safe refuge. Human in appearance, the infants were to wait until their superpowers developed so they could then return to Lorien to restore the planet. But the raiders have pursued them to Earth for a final mop up mission. A special charm placed upon the nine chosen youths means they must be killed in numerical order, hence the title character (Number Four) is the fourth on the Mogadarians’ hit list. The nine separate, fleeing to various parts of Earth; it’s only when a burning scar appears on their bodies that they know one of their kind has fallen.
Number Four has spent his life on Earth with his older protector, a father-like figure who calls himself Henri. They move from town to town, trying to live anonymous lives and stay several steps ahead of the alien assassins. The death of Number Three prompts a fateful move to Paradise, Ohio, a rather paradoxically named place for the duo. There, Number Four’s powers will develop to the fullest, and he’ll receive help from long-lost members of his race. But he’ll also fall in love with a sensitive Earth girl and find his desire for a normal teenage life growing day by day. But the Mogadorians will finally catch up with him, placing not only his life in jeopardy, but that of Henri and Number Four’s new-found friends. The war on Lorien may have ended, but the battle still wages on Earth.