This morning at 6 A.M., “DUSTWUN,” the first episode of season two of the “Serial” podcast, quietly made its début. It’s the first chapter in a season-long exploration of the case of Bowe Bergdahl, the American former prisoner of war. Bergdahl walked off his Army base in Afghanistan in 2009, and he was soon captured by the Taliban. Six U.S. soldiers who were killed in Afghanistan after his disappearance, some claim, died directly or indirectly because of his actions. Bergdahl was held captive for almost five years and released in a prisoner exchange in May, 2014. The first season of “Serial”—about the 1999 murder of a Baltimore teen, Hae Min Lee, and the conviction of her ex-boyfriend Adnan Syed for the crime—asked a specific question: Did he do it? That question raised broader questions about reasonable doubt, about memory and truth, about the U.S. system of justice. The second season does something different. The basic facts in the case of Bergdahl are known, and most parties involved agree on what they are. But what those facts mean, what Bergdahl actually experienced in the Army, his motivations for leaving his platoon, and the many terrible consequences of that decision are more complex, even existential.