Solution to the Puzzle on the Back Cover, Lower Left

I picked up my copy of The Lost Symbol at 12:01 a.m. at the Lincoln Center Barnes and Noble in Manhattan, here in New York City. Now, at a little after 2:00 a.m. Eastern time, I've dealt with a few other matters, and I am looking at something that many of us have been wondering about for months: the back cover, which does indeed have puzzles! This blog entry is the solution to one of them. (If you don't want to know, don't read on!)

[Incidentally, for those of you interested in the technical vocabulary and concepts of cryptography, the type of puzzle that we will be working with is a transposition cipher. This means that the letters of the message are all there in plain sight--but they are in a mixed-up order. How can one put them in the correct order? That is the challenge. I think you are seeing cryptographic history made here in The Lost Symbol; I think that forever afterward, this will be called a "magic square" or "Durer" cipher. Read on to see why.]

The lower left-hand corner of the back cover has a 4 x 4 grid of letters, like so:

Y U O E
M S T D
I I N H
R E K Y

This relates to a similar puzzle in The Lost Symbol that Robert Langdon struggles with. At one point, Langdon realizes that the solution to the puzzle is the magic square in the artwork, Melencolia I, produced during the German Renaissance by Albrecht Durer. (Durer was the subject of Clue #9; a reproduction of Melencolia I, magic square and all, is above.) Durer's magic square is a matrix of numbers:

16 3 2 13
5 10 11 8
9 6 7 12
4 15 14 1

The trick is to put the letters of the first matrix in the order indicated by the numbers of Durer's magic square. The lower right-hand corner of Durer's magic square is 1; this corresponds to the letter "Y" in the letter matrix, so "Y" should go in the first position (where there is already a "Y," no doubt just to confuse us all). But you get the idea. Sort the letters so that they fit into the following matrix of numbers:

1 2 3 4
5 6 7 8
9 10 11 12
13 14 15 16

and when you do this, you get the following matrix of letters:

Y O U R
M I N D
I S T H
E K E Y

which leads to the phrase:

"YOUR MIND IS THE KEY."

What a powerful statement! But what might it mean, in the context of this book? I think it means two things.

Certainly all the many challenges that Robert Langdon has to face in his adventures have to be solved through the use of his mind. In this world, where the forces of irrationality and superstition fight for supremacy, where irrational arguments are used to mold global politics, it is important to remember that our minds are the key.

Secondly, the conclusion of the novel, Chapters 133 and the Epilogue (which I will not spoil here), have some interesting things to say regarding the potential of the human mind.

Finally, the phrase "YOUR MIND" is almost certainly the key in a Caesar shift cipher (a transposition cipher) using the Freemason's cipher (a substitution cipher) that is another puzzle on the back cover. But that is another blogpost.

You can read more about Caesar shift ciphers, transposition ciphers, the Freemasons cipher, and substitution ciphers, in one of my forthcoming books. Australian puzzlemaster Denise Sutherland and I are publishing Cracking Codes and Cryptograms for Dummies in October or November (Wiley Publishing). I'll say more about it in this blog later on, but if you enjoy cryptography, codes, and puzzles, you'll like this book.

Now on to that other puzzle on the back cover . . . .

[I dedicate the solution of this puzzle to my wonderful wife, Kathleen Koltko-Rivera, who encouraged me to go out to pick up The Lost Symbol tonight, and accompanied me on a lovely nocturnal walk to do so. I love you, sweetheart. L., M.]