The most dire diplomatic crisis of the Trump administration, or maybe just the weirdest, began without much notice in November 2016, some three weeks after the new president was elected. An American working at the U.S. Embassy in Havana—some call him Patient Zero—complained that he had heard strange noises outside his home. “It was annoying to the point where you had to go in the house and close all the windows and doors and turn up the TV,” the diplomat told ProPublica. Zero discussed the sound with his next-door neighbor, who also worked at the embassy. The neighbor said, yeah, he too had heard noises, which he described as “mechanical-sounding.”

Several months later, a third staffer at the embassy described suffering from hearing loss he associated with a strange sound. Before long, more and more people at the embassy were talking about it. They, too, started to get sick. The symptoms were as diverse as they were terrifying—memory loss, mental stupor, hearing problems, headaches. In all, some two dozen people were eventually evacuated for testing and treatment.

The outbreak at the U.S. Embassy in Cuba wasn’t the only mysterious illness to pop up in the headlines. Around the same time that embassy officials were preparing to fly home, more than 20 students at an Oklahoma high school suddenly came down with baffling symptoms—uncontrollable muscle spasms, even paralysis. A few years before, a similar incident at a school in upstate New York had caught the attention of the local Fox News affiliate, which sent parents into a panic over the possibility that their children had been stricken by an unidentified immune disorder. But the Cuban mystery, the Trump administration insisted, was different. It was not some environmental mishap, but something far more diabolical.

Encouraged by U.S. officials, the media quickly unfurled a story that the mysterious sound was an “attack”—an act of war. Some kind of “acoustic weapon” had been secretly aimed at the diplomats, in an effort to reduce them to brain-damaged zombies. The story got told with a side helping of Cold War envy. Private contractors and the Pentagon’s own hip military lab, the Defense Advanced Research Projects Agency, had long been working to develop an arsenal of sound weapons. There had been some limited success with cumbersome devices like MEDUSA (Mob Excess Deterrent Using Silent Audio) and LRAD (Long Range Acoustic Device), designed to cause excruciating ear pain to disperse mobs on the ground and pirates at sea. The dream, of course, was to get past such giant blunderbusses to something more portable and powerful, like a Flash Gordon ray gun. But the air force, after some experiments, concluded that any such effort using sound waves would be “unlikely” to succeed due to “basic physical principles.” If someone had developed a portable acoustic weapon, they had leapfrogged well beyond the skill set of a Raytheon or Navistar and into the arsenal of Q Branch from the Bond movies.

For the past year, the effort to crack the mystery of which technology could have caused the physical symptoms in Cuba has sparked a ferocious nerd fight—one that has pitted scientist against scientist, discipline against discipline, The New York Times against The Washington Post. New theories have emerged, only to be knocked down or marginalized by the evidence, or put down by the petty sarcasm of rivals and skeptics.

Sift through these scientific feuds and media battles, however, and you will end up at a single unified theory that fully explains the diverse symptoms of the injured diplomats, as well as the seemingly inexplicable circumstances surrounding their ailments. Unlike a futuristic gun, it turns out, the cause of the pain and suffering at the American Embassy in Havana appears to be as old as civilization itself. Over the centuries it has been responsible for some of the most confounding epidemics in human history, from the Middle Ages in Europe to Colonial America. And in Cuba, it appears to have been weaponized for our time, opening up a whole new battlefield in Donald Trump’s war on reality.