For months, the coronavirus has crawled across the globe. One person at a time, it has passed through millions, reaching every corner of the earth. And it has not only infected people, but every aspect of our human cultures. Policymakers and the public sector face their biggest test in generations—some say ever—as lives and livelihoods hang in a terrible, delicate balance. Facing health crises, economic collapse, social and political disruption, we try to take stock of what the pandemic has done and will do. We asked Harvard Kennedy School faculty, in fields ranging from climate change to international development, from democracy to big power relations, to tell us how this epochal event has changed the world.