Brad Meltzer’s new book, History Decoded: The 10 Greatest Conspiracies of All Time, provides fascinating insight into 10 of the greatest conspiracies of all time. From D.B. Cooper to the fate of John Wilkes Booth to Area 51, Brad investigates the claims behind some of the most notorious conspiracies in American history.

After talking about D.B. Cooper, the assassination of Abraham Lincoln, the conspiracy behind the Confederate gold, the White House Cornerstone, and the Spear of Destiny over the last few weeks, on radio this morning, Brad joined Glenn to talk about Leonardo da Vinci and Area 51.

Brad began with a recap of Leonardo da Vinci.

“So Leonardo da Vinci is the number 4. We’re counting down the top greatest conspiracies of all time. We all know the Da Vinci Code, and it sells a lot of books and that’s great.  This is the real version,” Brad said. “This is a guy, you know, talk about the great, true Renaissance thinker, right? He invents the submarine. He invents SCUBA. He invents a pre-helicopter, all the times when nobody in the whole world should be thinking of these things… But what he has is this book called the Codex Atlanticus. And a codex is really just a collection of ancient works. That’s what it is. And it’s really a collection of his notes… It’s almost like a file cabinet of da Vinci’s brain. So all the things he was working on, all the sketches, all the notebooks, all the papers, they all get put together.”

The value of a da Vinci codex is in the tens of millions of dollars, but what makes the Codex Atlanticus unique is that it is missing a page. At some point in history, page 1,033 was removed and believed to be lost. A few years ago, while going through an old Italian library, a woman found what appeared to be a da Vinci drawing. The sheet of paper was later verified to be page 1,033 of the Codex Atlanticus.

So why all the fuss about this particular page?

“And what was so fascinating about it and why people were so obsessed with this one page is it was the only page in Leonardo da Vinci’s entire codex, in his entire book that was about prophecies,” Brad said. “And now you have a real mystery, right? Why hundreds of years ago, centuries ago does someone go and rip out the one page on prophecies that Leonardo da Vinci writes about?”

In History Decoded, Brad explores a lot of the different conspiracies surrounding the page. Since we all know that da Vinci liked to hide symbols and messages in his works of art, people have tried to decode the drawing on page 1,033. Others have made the case that da Vinci actually had prophecies in many of his paintings (i.e. the flood in the Mona Lisa). But none of this truly explains why the page was removed from the Codex Atlanticus.

To learn more about Brad’s research on Area 51, watch the clip below: