Ender's Game

Orson Scott Card

Ender Wiggin, the third in a family of child geniuses, is selected by international military forces to save the world from destruction.Ender is abruptly promoted to Salamander Army. There Ender made a friend named Petra Arkanian, the only girl in the army. Ender is made commander of Dragon Army and given a group of soldiers, most of them Launchies. Ender is then transferred out of Battle School to Command School.