Orson Scott Card's Ender's Game is the winner of the Nebula and Hugo Awards

In order to develop a secure defense against a hostile alien race's next attack, government agencies breed child geniuses and train them as soldiers. A brilliant young boy, Andrew "Ender" Wiggin lives with his kind but distant parents, his sadistic brother Peter, and the person he loves more than anyone else, his sister Valentine. Peter and Valentine

From the #1 New York Times bestseller

At the Battle School, there is only one course of study: the strategy and tactics of war. Humanity is fighting an alien race, and we fight as one. Students are drawn from all nations, all races, all religions, taken from their families as children. There is no room for cultural differences, no room for religious observances, and there is certainly no room for Santa Claus.

But the young warriors disagree.