How does Ender's Game end?

At the end of "Ender's Game," Ender Wiggin discovers that he has inadvertently led the human fleet to annihilate the alien Formics, believing it was just a simulation. Overcome with guilt for his actions, he seeks redemption by finding a surviving Formic queen egg and vows to help it find a new home, hoping to atone for his role in their destruction. The novel concludes with Ender leaving Earth to embark on a journey of self-discovery and to prevent the mistakes of the past from repeating.