Xenocide: Ender Saga: Book 3 (Ender's Game)

Ender and Valentine Wiggin, brother and sister whose lives have shaped history. Valentine is 'Demosthenes', whose subversive, incendiary writings fight the monstrous power of Starways Congress, masters of the Hundred Worlds. As a child, Ender commanded a warfleet that wiped out a planet. The triumph of his life could be his fight to stop it happening again. It might be his tragedy that he cannot. Congress has sent a warfleet to Lusitania, home to Ender, his family, two alien species and the deadliest virus ever known. The warfleet carries an order to destroy, to commit Xenocide.