On October 22, 1962, President John F. Kennedy broadcast a special message to the nation from his office in the White House.

Here is President Kennedy as he delivered that message bearing on recent events in Cuba.

Good evening, my fellow citizens. This government, as promised, has maintained the closest surveillance of the Soviet military buildup on the island of Cuba.

Within the past week unmistakable evidence has established the fact that a series of offensive missile sites is now in preparation on that in prisoned island.

That was President John F. Kennedy giving what was perhaps the most harrowing speech in American history.

As Kennedy spelled out, the US government had collected intelligence that the Soviets were installing on Cuba ballistic missiles capable of carrying nuclear warheads that could target cities throughout the United States, weapons, he said, of sudden mass destruction.

For more than a half century there was a common understanding of how the US government knew about this from U.2 spy planes flying over Cuba and taking photographs of the missile sites.

But now new evidence has emerged that there was a whole other piece to the story spelled out in a fascinating new piece of investigative journalism.

It turns out that there was a CIA officer, unknown to the history books, named Tom Uitt, who was placing covert agents on the Cuban island as part of Operation Cobra, a secret CIA plan to overthrow the regime of Fidel Castro.

And it turns out it was Tom Uitt's Cobra agents who first identified those missile sites and tipped off the CIA to the weapons build up, not the U.2 spy planes.

How did we not know this before? And why are we just learning about it now? Especially relevant questions at a moment the US government is once again seeking to overthrow a government in South America.

We'll discuss with the journalists who piece the story together our Yahoo News colleague, National Security correspondent Sean Naylor, on this episode of Buried Treasure.

Because people have got to know whether or not they're President Cobra, well I'm not a Cobra.

I told the American people I did not trade arms for hostage. My heart and my best intentions still tell me that's true, but the facts and the evidence tell me it is not. I did not have sexual relations with that woman.

There will be no lies. We will honor the American people with the truth and nothing else.

I'm Michael Isigov, Chief Investigative correspondent for Yahoo News. And I'm Dan Clyde, man that are in chief of Yahoo News. So Sean, welcome to Buried Treasure. It is great to be here.

You did a rare thing in this extraordinary piece that just went up on Yahoo News. You managed to break news on one of the most scrutinized and crucial events in modern US history.

Tell us quickly how Tom Hewitt and his spand of agents pulled this off. And then I want to talk to you a little bit about how you got onto this story in the first place.

So Tom Hewitt was a case officer in the Miami station of the CIA, which in the early 1960s was the largest station that the CIA had in the world.

And with hundreds of employees basically running operations into Cuba, analyzing what was going on in Cuba and so forth as Castro's grip on power tightened and as Cuba became increasingly communist.

Tom Hewitt ran a small team of agents initially into Western Cuba. And we describe in the story how they infiltrated Cuba. And he had trained particularly his principal agent, a man called Esteban Marquez Novo, who was a former Cuban military member in the sort of top level clandestine trade craft.

And he'd given him about a six to eight month training course in how to do that, all of that sort of stuff. And after infiltrating the team, it turned out that Marquez Novo was a absolute natural at this. And he was able to build up a network inside of Western Cuba that eventually some estimates included as many as a hundred sort of members.

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