Xenocide is the third book in the Ender’s Game saga by Orson Scott Card. It is preceded by Ender’s Game and Speaker for the Dead and is followed by Children of the Mind, Ender in Exile, and The Last Shadow.

In Ender’s Game, Ender is enrolled in Battle School as a young boy; there he studies to be a soldier to fight in the war against the Formics, or “buggers.” He goes to classes, plays the Fantasy Game on his tablet, and participates in zero-gravity mock battles. He thrives at Battle School because of his open mind and creativity, and he becomes the youngest person to be given command of a squadron. He grows to resent the government attempting to control him and takes a break during which time Valentine, his older sister, is sent to encourage him to return to his training. He successfully completes his elaborate final “test” in which he destroys an entire planet using the M. D. Device. Afterward, he is told that he was actually leading real pilots in a real battle and has just defeated the Formics once and for all. Later, he discovers that the Formics’ previous violence against humans was due to a tragic misunderstanding.