Fifth Outside Quarter Reading Post

I have recently finished my book and the last 50 pages or so have completely changed the story.
Amir and Baba leave for America because the Russians are invading Afgahnistan. Hassan and Ali are living in a remote village faraway and have no more contact with Amir and his father. Amir gets married to Soraya (he lives in California now) becomes a published author and his father dies of lung cancer. Amir gets a call from Afgahnistan and hears that Rahim Kahn is dying and he wants to see him. Amir goes to Rahim. Rahim tells him that his father had an affair with Ali's wife and that Hassan is his half brother. Amir ends up searching for Hassan's orphaned son (Hassan was killed by the Taliban). Assef became part of the Taliban and has Hassan as his slave. Assef comes very close to killing Amir but them Sohrab (Hassan's son) saves him with his sling shot (Hosseini 289). Amir tries now to get custody of Sohrab and to take him to America, the only way he can do that is if he puts Sohrab in another orphanage temporarily. Sohrab then attempts suicide. Amir finds him, takes him to the hospital and eventually back to America (Amir was going to tell Hassan he didn't need to go back to an orphanage when he found him almost dead). Sohrab doesn't talk for the rest of the book. The last scene is Sohrab and Amir running a kite together in California and Sohrab smiles for the first time. (324).
When Amir finds out that Hassan is his half brother, he flies into a rage and yells at Rahim. Understandably so, he now understands why his father paid so much attention to Hassan. In teh book it says that Amir was the "sociably acceptable son". If people had known about Baba's affair with Ali's wife, he would have lost his reputation and Ali would have been incredibly hurt. Amir now can relate to Baba a little bit. Baba had also hurt his best friend, how could he live with him now and know that he has hurt him so much? Amir's guilt drove Hassan away, but Baba kept Ali around as a reminder of the wrong he did. This was most likely the motivation for all the good things that Baba did in Afgahnistan, like build the orphanage. Amir feels even guiltier for what he did to Hassan now that he knows he did it to his own brother. When Rahim tells Amir that Hassan had a son who is still out there and suffering, Amir was cowardly at first and didn't want to have to remember all that he did, he thought that it was all in the past. When he finally relizes that this is the way to redeem for himself and honor Hassan, he knows he must rescue Hassan from his Taliban captors.