Raul Castro seemed rattled.
The Cuban president sent for the top American envoy in the country to address grave concerns about a spate of U.S. diplomats harmed in Havana. There was talk of futuristic "sonic attacks" and the subtle threat of repercussions by the United States, until recently Cuba's sworn enemy.
The way Castro responded surprised Washington, several U.S. officials familiar with the exchange told the Associated Press.
In a rare face-to-face conversation, Castro told U.S. diplomat Jeffrey DeLaurentis that he was equally baffled and concerned. Predictably, Castro denied any responsibility. But U.S. officials were caught off guard by the way he addressed the matter, devoid of the indignant, how-dare-you-accuse-us attitude the U.S. had come to expect from Cuba's leaders.
The Cubans even offered to let the FBI come down to Havana to investigate. While U.S.-Cuban cooperation on law enforcement has improved, this level of access was extraordinary.
"Some countries don't want any more FBI agents in their country than they have to — and that number could be zero," said Leo Taddeo, a retired FBI supervisor who served abroad. Cuba is in that group.
The list of confirmed American victims was much shorter on Feb. 17, when the U.S. first complained to Cuba. Today, the number of "medically confirmed" cases stands at 21 — plus several Canadians. Some Americans have permanent hearing loss or mild brain injury. The developments have frightened Havana's tight-knit diplomatic community.
At least one other nation, France, has tested embassy staff for potential sonic-induced injuries, the AP has learned.
But several U.S. officials say there are real reasons to question whether Cuba perpetrated a clandestine campaign of aggression. The officials weren't authorized to discuss the ongoing investigation and demanded anonymity.
When the U.S. has accused Cuba in the past of misbehavior, such as harassing diplomats or cracking down on dissidents, Havana has often accused Washington of making it up. This time, although Castro denied involvement, his government didn't dispute that something troubling may have gone down on Cuban soil.
Perhaps the picture was more complex? Investigators considered whether a rogue faction of Cuba's security forces had acted, possibly in combination with another country such as Russia or North Korea.
Nevertheless, anger is rising in Washington. On Friday, five Republican senators wrote to Secretary of State Rex Tillerson urging him to kick all Cuban diplomats out of the United States and close America's newly reestablished embassy in Havana.