Ender is at school until he gets drafted into the IF by Col. Graff.
Fight vs. Bonzo
Ender accepts the draft, not that he had much of a choice and leaves Earth and his Family to go to the Battle School currently orbiting the planet to train him for future service as an office.
Final Boss Fight & Reward
In battle school, Ender meets a good friend who helps him along the way, especially while fighting the buggers in the end.
"Return to Home"
Throughout his time at Battle School, Ender is always at the front of the pack when it comes to academics and wit. He was promoted to the classes above him and Bonzo, his first commander, hated him.
When Ender fights the buggers in the final battle, he is confronted with the reward of saving the human race but also challenged because he kills an entire species.
PEW PEW PEW PEW PEW
Although Ender is a hero to the entire species, he cannot return to home because there are fears that many nations would use him to their advantage to take over the world. Therefore, he has no other option but to accept the Battle Station as his new home.