The Kite Runner by Khaled Hosseini

Rahim Khan slowly uncrossed his legs and leaned against the bare wall in the wary, deliberate way of a man whose every movement triggers spikes of pain. Outside, a donkey was braying and some one was shouting something in Urdu. The sun was beginning to set, glittering red through the cracks between the ramshackle buildings.

It hit me again, the enormity of what I had done that winter and that following summer.