It's just another day of high school for Zack Lightman. But then he glances out of his classroom window and spots the flying saucer. Zack thinks he's going crazy. The UFO he's staring at is straight out of the videogame he plays every night, Armada - in which gamers just happen to be protecting the earth from alien invaders. But what Zack's seeing is all too real. And his skills are going to be needed to save the earth from what's about to befall it. Yet even as he scrambles to prepare for the alien onslaught, Zack can't help thinking of all the science-fiction books, TV shows and movies he grew up reading and watching. Doesn't something about this scenario seem a little too... familiar ?