A DISEASE OUTBREAK blossoms in China. Exactly how it emerges, far from the eyes of any surveilling scientist, no one can quite explain. It spreads with incredible speed, killing in wide swaths, freezing transport and trade, and causing vast economic disruption. Hitchhiking on global travel, it circles the world. There is no cure, and no vaccine. Inevitably, it arrives in the Americas, in July 2021.

Yup, 2021. The year is not a typo. This outbreak isn't Covid; it is a parallel, hidden pandemic, a deadly animal disease called African swine fever that was detected in the Dominican Republic in July. African swine fever poses no risk to humans, but it is incredibly destructive to livestock: Those deaths in China were millions of pigs, at least one-quarter—and possibly one-half—of the entire herd of the world's largest pork producer.