From New York Times bestselling author Orson Scott Card, Ender's Game—adapted to film in 2013 starring Asa Butterfield and Harrison Ford—is the classic Hugo and Nebula award-winning science fiction novel of a young boy's recruitment into the midst of an interstellar war.

In order to develop a secure defense against a hostile alien race's next attack, government agencies breed child geniuses

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An all-new trilogy about the Second Formic War. The first invasion of Earth was beaten back by a coalition of corporate and international military forces, and the Chinese army. China has been devastated by the Formic's initial efforts to eradicate Earth life forms and prepare the ground for their own settlement. The Scouring of China struck fear into the other nations of the planet; that fear blossomed into drastic action when scientists determined...

"A coalition of Earth's nations barely fought off the Formics' first scout ship. Now it’s clear that there's a mother-ship out on edge of the system, and the aliens are prepared to take Earth by force. Can Earth's warring nations and corporations put aside their differences and mount an effective defense?"--

One hundred years before Ender's Game, the aliens arrived on Earth with fire and death. Earth Afire by Orson Scott Card and Aaron Johnston is the story of the First Formic War.
Victor Delgado beat the alien ship to Earth, but just barely. Not soon enough to convince skeptical governments that there was a threat. They didn't believe that until space stations and ships and colonies went up in sudden flame.
And when that happened,

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Child-hero Ender Wiggin might be humanity's only hope. Ender is recruited into the International Fleet's legion of child warriors, training to become a commander in Earth's defenses.