It started small, with an unprepared band of Marine reservists encountering deadly extraterrestrial visitors in the backwoods of Missouri. But this fatal First Contact rapidly escalates into a global crisis as mankind discovers that two warring species of aliens have invaded our world through a network of hidden interdimensional portals. The apocalyptic conflict between the hastily labeled "Blues" and "Grays" has already devastated their home planet. Now Earth has become the final battleground in a cataclysmic war whose origins are barely understood.