Amir decides to return to Afghanistan on the second page of the novel (Chapter One), though he does not yet realize what his objective will be. He has only been assured in a phone call from Rahim Khan that "There is a way to be good again." It is only after Amir arrives in Peshawar, Pakistan to meet with Rahim does he finally realize what he must do. Hassan and his wife have been murdered by the Taliban, and their son, Sohrab--who Amir will soon discover is also his own nephew--is missing. After Rahim informs Amir of Baba's terrible secret--that Hassan is also his son, and Amir's half-brother--Amir leaves his apartment in disgust. But he soon returns, remembering Rahim's promise that there was
A way to end the cycle.
With a little boy. An orphan. Hassan's son. Somewhere in Kabul. (Chapter Nineteen)
Rahim was praying when Amir found him, and
Then I told him I was going to Kabul. Told him to call the Caldwells in the morning.
"I'll pray for you, Amir jan," he said. (Chapter Nineteen)
This quote can be found in the final sentences of Chapter Nineteen, page 227 (in my paperback version from 2005).