Xenocide

Ender and Valentine Wiggin are brother and sister who both share the gift of genius. The monstrous Starways Congress has sent a warfleet to their home planet of Lusitania, containing two alien species and the deadliest virus ever known. They have also issued the order to destroy the planet.

Orson Scott Card is an American novelist, critic, public speaker, essayist and columnist. He writes in several genres but is known best for science fiction. His novel Ender's Game (1985) and its sequel Speaker for the Dead (1986) both won Hugo and Nebula Awards, making Card the only author to win both science fiction's top U.S. prizes in consecutive years.