They were creatures seemingly spawned straight from the pits of hell - demons, zombies, fire-breathing imps, all too horrifically close to the stuff of nightmare to be real. But they were. And on the inhospitable moons of Mars, Corporal Flynn "Fly" Taggart, Earth's last line of defense against a seemingly inexhaustible supply of alien warriors, beat them back almost singlehandedly. Only to discover that the war had barely begun. Because while Taggart was fighting them on Mars, the aliens had established a beachhead on Earth itself. Now, with the aid of a fourteen-year-old female computer genius, an unrepentantly Mormon sniper, and the best soldier in this women's army, "Fly" Taggart must defeat the aliens - and their treacherous human allies - yet again...