The year is 2070. Forty years have passed since the devastating alien invasion of earth, and the world is desperately searching for soldiers to lead them to victory when the "Buggers" return. Because of this, they're now drafting young children, who pass a rigorous screening, and sending the best of them to a Battle School orbiting Earth, from which they are trained to be ready for war in the far reaches of space.

Into the unyielding pressure of military training comes six-year-old Andrew "Ender" Wiggin, who even as his adult teachers, rivals among fellow students, and the strange unseen influence of alien invaders, struggles to keep his humanity.

His genius raises him to the top of the intensely competitive games in the Battle Room, an immense null-gravity chamber where armies of children/soldiers engage in mock combat. Yet his real struggles are off the playing field with a dangerous older boy who is determined that both he and Ender cannot survive this place; with his theacher who won the last war on a fluke and now is trying to prepare Ender to win the next war by skill rather than luck; and with himself, as he wrestles with his on demons, desperate to remain a decent human being even as he sees himself being transformed into exactly the same kind of monster as the buggers themselves.