On a bright autumn weekend, a black Mercedes-Maybach rolled across the Yalu River, carrying a man whose whereabouts have always been watched with more anxiety than almost anyone else on earth. Kim Jong-un, North Korea’s leader, was on his way to Dandong, China—not by his private train or airplane, as on all five of his previous visits to China, but by car. The New Yalu River Bridge, which had opened just days earlier on October 15, became the stage for an unusually personal piece of diplomacy. North Korean state television aired footage of the leader’s car crossing the gleaming span,…

Every couple of years, the same false stories come creeping back. A claim that an election was rigged before a single vote has been cast. An old video of violence, stripped of its date and place, suddenly presented as breaking news. For fact-checkers, this means doing the same painstaking work again and again—investigating claims they have already debunked, while new lies keep piling up. It takes time, money, and access to reliable information, none of which are easy to come by. Fact-checkers are the people whose job is to chase claims, test them against evidence, and tell the public what…