The largest port on the Arabian Sea, Karachi today has a population over 20 million, on a par with Mumbai, and ranks as the world’s eighth biggest city. Commanding the north-east quadrant of the ocean, with a hinterland stretching up the Indus Valley to Afghanistan, it has been the principal entry-point for us arms and supplies in the ‘war on terror’, while refugees—and heroin—have flowed in the opposite direction. From the bloodstained birth of Pakistan with the Partition of British India, the city’s explosive growth has more often been fuelled by the ‘push’ of geopolitical, agrarian and ecological crises than by the ‘pull’ of economic development. Life in its sprawling katchi abadis, or ‘unpaved settlements’, has much in common with that of other giant undercities, such as Mumbai’s, with the exception that violence plays a significantly greater role here. The vast majority of Karachiites are not only entangled in competition with each other, in a desperate struggle for survival, but must also contend with a brutal climate of aggression fuelled by gangsterized political groupings, the most influential of which also control the armed force of the state. In what conditions do its inhabitants live and what could drive increasing numbers of newcomers to try to survive here?