Ender's Game recap

In a future still recovering from two invasions by an insectlike alien species, the world's military trains brilliant children to command the war against a feared third attack. Six-year-old Ender Wiggin, chosen for his rare mix of empathy and ruthlessness, is taken to an orbiting Battle School, where Colonel Graff deliberately isolates him to forge him into a leader. Ender rises through the school's zero-gravity war games, enduring bullying, manipulation, and crushing pressure, and eventually commands his own army with unmatched skill, though the strain nearly breaks him. Promoted to Command School, he is trained by Mazer Rackham, the hero of the last war, and directs entire fleets through grueling battle simulations. In a final test against overwhelming odds, Ender destroys the enemy's home planet, only to learn afterward that the simulations were real and that he has wiped out the entire alien species. Devastated by the deception, he refuses to return to Earth and leaves to help settle a new world, where he discovers the aliens were not the monsters humanity believed and dedicates himself to honoring the dead.

In a future where humanity has barely survived two invasions by an insectlike alien species called the buggers, the world government trains gifted children to become military commanders for an expected third war. Andrew, called Ender, Wiggin is a brilliant, empathetic six-year-old, a rare third child in a family limited by law to two, watched since birth as a candidate. After the monitoring device implanted at his neck is removed, a school bully corners him and Ender responds with overwhelming force to make sure the threat can never return. At home he is caught between his loving sister, Valentine, and his cruel, power-hungry brother, Peter. Colonel Graff, an officer of Battle School, recruits Ender and takes him away to an orbiting military academy, at once beginning to isolate him from the other recruits so that he learns to depend only on himself.

At Battle School, Ender endures Graff's deliberate manipulation, which turns the other students against him. He masters the school's central exercise, mock battles fought with freeze weapons in a weightless arena, quickly outthinking older students with unconventional tactics. In his free time he is drawn into a strange computer fantasy game that seems to adapt itself to his mind, and he forces his way past one of its supposedly unbeatable challenges through sheer stubbornness. Despite his isolation he begins forming real bonds, notably with a boy named Alai, and he organizes extra practice sessions to sharpen his own skills and those of the recruits who follow him.

The teachers accelerate Ender's training, promoting him early into Salamander Army under the resentful commander Bonzo Madrid, who forbids him to fight; a skilled soldier named Petra secretly trains him instead. Reassigned soon after to Rat Army, Ender keeps mentoring younger students in private practice and hears older soldiers like Dink Meeker voice suspicion that the adults are manipulating them all. Meanwhile, back on Earth, his siblings Peter and Valentine secretly build political influence under false identities on the world's computer networks, with Peter aiming to seize real power. Ender's steady, brilliant success leads the teachers to hand him command of his own newly formed army.

Ender is given command of Dragon Army, assembled from castoffs and very young recruits, among them a gifted small boy named Bean. He trains them with inventive tactics and leads them to victory after victory as the teachers rig the games against him, forcing battles under increasingly unfair conditions to test his limits. The relentless schedule isolates and exhausts him. Bonzo Madrid's hatred finally boils over: he confronts Ender with a gang of boys, and Ender, fighting to survive, beats Bonzo so severely that the threat is ended for good, though he is not told the full outcome. Drained and disturbed by his own capacity for violence, Ender is pushed to the edge of collapse.

Worn down and frightened by what he is becoming, Ender is sent back to Earth for a rest, where the military quietly uses his sister Valentine to persuade him not to give up. He agrees to keep going and is sent far out in the solar system to Command School. There his teacher is Mazer Rackham, the legendary hero who destroyed the alien fleet in the previous war and was long believed dead. Mazer trains Ender to command entire fleets through a realistic battle simulator, with his old friends serving as his squadron leaders, driving him through brutal, exhausting practice engagements while telling him the real invasion is near.

For his final examination, Ender faces an impossible scenario: the enemy fleet vastly outnumbers his own around their home planet. He orders a forbidden weapon fired directly at the planet itself, destroying it along with the entire enemy fleet. Only afterward does Mazer reveal the truth: the exercises were never simulations but real battles fought by actual human fleets under Ender's command, and Ender has just wiped out the entire bugger species. Devastated to learn he committed genocide without knowing it, Ender falls into a long breakdown. On Earth, war erupts among the victorious nations and Peter maneuvers toward ruling the world. Ender refuses to go home; instead he travels with Valentine to help settle a former bugger world, where he discovers that the aliens were not the mindless enemy humanity believed. They left behind a dormant hive queen and a message meant for him, and he takes up her egg to one day revive her kind, writing a book of atonement that becomes the first work of the Speaker for the Dead.

Ender's final training exercise turns out to have been the real war: unknowingly commanding actual human fleets he believed were only simulations, he fires a planet-destroying weapon at the buggers' homeworld, annihilating their entire species. The adults had concealed the truth so that he would fight without the moral weight of committing genocide. Ender is left shattered by what he was tricked into doing. On Earth, the alliance that fought the aliens fractures into war, and his brother Peter, working through politics and propaganda, rises toward ruling the world. Refusing to be used again or to go home, Ender leaves with his sister Valentine to help colonize one of the buggers' abandoned worlds. There he discovers that the aliens had come to understand him and had preserved a single dormant hive queen, leaving her in his care along with a plea for their revival. Ender accepts the burden of carrying the queen egg to find her a new home one day, and he writes a book told from the aliens' point of view that recasts them as victims rather than monsters. Under the name Speaker for the Dead, he begins a life of atonement, leaving open the possibility of the buggers' eventual return.