Amir's return to Afghanistan proves to be both a courageous journey as well as a way to seek redemption for his past sins against Hassan. When Baba's old friend, Rahim Khan, assures Amir that
There is a way to be good again,
Amir begins the voyage that will provide him with the healing process that he has been seeking since his move to California. When Rahim reveals that Hassan is actually Baba's son--and Amir's half-brother--and that Hassan's son is missing in Afghanistan, it becomes clear to Amir that Rahim's intent is for him to find Sohrab.
I began to see where he was going. But I didn't want to hear the rest of it. I had a good life in California... a good marriage, a promising writing career... I didn't need any of this... (Chapter 17)
The dangers were many, including sneaking back into Taliban-occupied Kabul, donning a fake beard to hide his true identity, and negotiating with a Taliban official for Sohrab's release. In the end, Amir found partial redemption from the beating he took from Assef;
My body was broken--just how badly I wouldn't find out until later--but I felt healed. Healed at last. (Chapter 22)
And Amir receives further atonement at the end of the story when he bravely offers to run the kite for Sohrab, producing a smile from the silent and emotionless boy.
It was only a smile, nothing more. It didn't make everything all right...
But I'll take it. With open arms. (Chapter 25)