We are circling over Buenos Aires. The airspace is crowded with other planes, all of them holding like ours. The pilot explains that it is the fault of the humo , or smoke, a word I will hear a great deal in the coming week.

An hour and a half later I am on the ground, head pounding, breathing in the humo . The cover of the Clarín newspaper shows someone gagging and declares: "The Worst Atmospheric Contamination in History."