Contrary to popular belief, the Cuban missile crisis did not end with the agreement between the US and Soviet Union in October, 1962. Unknown to the US at the time, there were 100 other nuclear weapons also in the hands of Cuba, sparking a frantic - and ingenious - Russian mission to recover them.
In November 2011, aware that the 50th anniversary of the most dangerous few weeks in history was less than a year away, my Russian colleague Pasha Shilov and I came across several new accounts that changed our perspective on the Cuban missile crisis and how much we thought we knew about it.
Growing up in Berkshire, England, through the nuclear paranoia of the 1980s, with Ronald Reagan's Cruise and Pershing missiles stationed only 30 miles away from my family home, I was inculcated with a keen awareness of Cold War brinkmanship.
Pasha grew up in Moscow and described how it was from the Soviet point of view - equally frightening by his account.
But what we've now learned about the chilling events of October and November 1962 has put our own experiences into perspective - and maybe given rise to a few more grey hairs along the way.
Nuclear disaster averted
Image captionThe crisis sparked protests worldwide
· Cuban missile crisis ignites when, fearing a US invasion, Castro agrees to allow the USSR to deploy nuclear missiles on the island
· The crisis was subsequently resolved when the USSR agreed to remove the missiles in return for the withdrawal of US nuclear missiles from Turkey
Timeline: US-Cuba relations
BBC Archive: Cuba and the Cold War
Our investigations took us to St Petersburg and the Soviet Submariners Veterans' Society via the National Security Archive in Washington DC, where Svetlana Savranskaya, the director of the Russian archives, told us an incredible story.
There had been a second secret missile crisis that continued the danger of a catastrophic nuclear war until the end of November 1962.
This extended the known missile crisis well beyond the weekend of 27-28 October, the time that had always been thought of as the moment the danger finally lifted with the deal between Kennedy and Khrushchev to withdraw the Soviet missiles in exchange for a US promise not to invade Cuba.
The secret missile crisis came about through an unnerving mix of Soviet duplicity, American intelligence failures and the mercurial temperament of Fidel Castro.
The Cuban leader, cut out of the main negotiations between the superpowers over the fate of the long range Soviet missiles stationed in Cuba, began to cease cooperation with Moscow.
Fearing that Castro's hurt pride and widespread Cuban indignation over the concessions Khrushchev had made to Kennedy, might lead to a breakdown of the agreement between the superpowers, the Soviet leader concocted a plan to give Castro a consolation prize.
The prize was an offer to give Cuba more than 100 tactical nuclear weapons that had been shipped to Cuba along with the long-range missiles, but which crucially had passed complet...