The Beginning and the End - Naguib Mahfouz

Set in Cairo during World War II, this novel is a masterpiece of human compassion reflecting with sympathy and well-balanced pathos the material, moral, and spiritual problems of an Egyptian family.
Suddenly confronted with poverty when the father, its sole support, dies unexpectedly, the family's middle-class respectability and conformity can only be supported on the backs of a brother and a sister who sacrifice their own reputations by immersing themselves in the seamy underworld of Cairo.