Soul mates from birth, Karim and Raheen finish one another's sentences, speak in anagrams and lie spine to spine. They are irrevocably bound to one another and to Karachi, Pakistan, a city that is violent, polluted, corrupt, vibrant, brave and, ultimately, home.

As the years go by, they let a barrier of silence build between them until they are brought together during a summer of strikes and ethnic violence in Karachi when Raheen first comes to know a secret about the past of their parents. Something had happened in 1971, the year the war broke out with the Bengalis in then East Pakistan, now Bangladesh. Karim's mother is a Bengali, an unpleasant truth to live with, in the Karachi of 1971, which leads to unpredictable happenings in their parents' lives as well as theirs.