Since China abandoned its restrictive “zero Covid” policy about two weeks ago, the intensity and magnitude of the country’s first nationwide outbreak has remained largely a mystery. With the country ending mass testing, case counts are less useful. The government has a narrow definition of which deaths should count as caused by Covid. Anecdotal evidence, like social media postings of hospital morgues overcrowded with body bags, is quickly taken down by censors. Now, a picture is emerging of the virus spreading like wildfire. One province and three cities have reported Covid estimates far exceeding official tallies in recent days. At...