When the coronavirus was first detected in Wuhan in late 2019, reporter Liao Jun of China's official Xinhua News Agency told conflicting stories to two very different audiences. Liao's news dispatches assured readers the disease didn't spread from person to person. But in a separate confidential report to senior officials, Liao struck a different tone, alerting Beijing that a mysterious, dangerous disease had surfaced. Her reports to officials were part of a powerful internal reporting system long used by the ruling Communist Party to learn about issues considered too sensitive for the public to know. Chinese journalists and researchers file...