In Japan’s stormy summer of 1983, Ikuo Ishiyama couldn’t stop thinking about a chilling pattern among his patients. They were dead, but that wasn’t what troubled him. As a specialist in forensic medicine at Tokyo University, Ishiyama was accustomed to seeing dead bodies. However, these victims—numbering in the hundreds—shared a similar demise. “The symptoms are the same,” he told the Los Angeles Times. “Young men without medical problems are essentially dying in the same way, without warning.” What way was that? That may be the most mysterious detail: All of…
