When diplomats and other personnel at the newly reestablished U.S. Embassy in Havana began falling mysteriously ill late in 2016, suspicion immediately fell on hard-line elements in the Cuban government that were not eager to see a thaw in the long-frozen relationship across the tropical Florida Straits. But that explanation did not line up well with nearly 60 years of experience with a stable – even ossified – communist regime. Power passed relatively uneventfully after the incapacity and death of Fidel Castro. Dissenters tended to defect and flee the island, rather than take active steps to oppose the government. Opposition was especially rare from dissenters within the regime itself. So as soon as Americans, followed by their Canadian counterparts, began reporting unexplained vertigo, headaches and hearing nonexistent noises, alternative answers were on the table as well.