China’s zero-covid policy is being stretched to breaking point as the virus makes its way through the city. Supplies are low, residents are angry and there is no end in sight. The debate about air conditioning in America’s sweltering prisons will only heat up further. And how a dispute about time from exactly a century ago remains timely today. Additional audio provided courtesy of Matthew Florianz. For full access to print, digital and audio editions of The Economist, subscribe here www.economist.com/intelligenceoffer