"Given pride of place in an unassuming museum on the East Coast of America is a pair of 200-year-old duelling (sic) pistols shrouded in mystery.
The intricately decorated guns were said to have been forged from the iron of a fallen meteorite.
They were a unique gift from the commander of a South American region, which would later become Argentina, to the fourth US president, James Madison.
"Permit me therefore to present to your Excellency... a specimen of the first essays of the manufacture of arms established in the provinces of Buenos Ayres and Tucuman," wrote General Ignacio Alvarez in an accompanying 14-page letter.
Over time, they passed into the hands of Madison's successor - James Monroe - and are now on display at a museum dedicated to him.
Since that time, the story of their origin has gone unquestioned.
Now, scientists armed with a battery of hi-tech machines have probed the pistols in unprecedented detail.
Their findings cast doubt on the accepted theory of their origins and have thrown up a whole new set of questions for historians about the guns and the motives of the original protagonists.
"It's made the mystery even more mysterious," Meghan Budinger, curator at the James Monroe Museum and Memorial Library, told BBC News.