“I’m afraid I’m not sufficiently well up in the Scriptures to notice anything peculiar about them. I should say they were from the Old Testament, but I couldn’t tell you what part of it.”
“The texts are from the Old Testament, from Jeremiah XXV and Isaiah VII. They are remarkable for the fact that they represent two passages—the only two instances in the whole Bible—where the writers used cryptograms to hide their actual meaning. In the first instance the prophet, Jeremiah, living in dangerous times, veils his attack on the King of Babylon by writing Sheshak for Babel—Babylon; that is, instead of using B B L, the second and twelfth letters of the Hebrew alphabet, from the beginning, he wrote Sh Sh K from the end—a simple form of cryptogram which is frequently used, even now. In the second instance the prophet Isaiah, working on a very similar form of cryptogram, writes ‘Tabeal’ for ‘Remaliah.’
“Now, we are faced by two facts concerning the presence of these two texts on the paper containing the cryptogram. In the first place, the cryptogram was complete without the texts; for what purpose, then, could they have been at the bottom of the sheet except to give a clue to the discovery of that keyword without which no recovery of the hidden treasure was possible, unless it was found by a lucky chance? In the second place, the selection by the old man of the only two cryptographic texts in the Bible was certainly not chance, but part of a deliberate harmonious design to guide the intelligent searcher to the right keyword. He was evidently versed in cryptography, constructed this one as carefully as a mechanic putting together a piece of mechanism, fitting all the parts carefully into one another. The figures in the centre of the circle give the key to the outside figures: the outside figures are the key to the cryptographic table of letters from which the cryptogram is to be solved; there remains the key to be found. It is not likely that the composer of such an ingenious cryptogram would leave the keyword to guesswork.
“The whole thing is a Bible cryptogram from first to last: figures, letters, words, and texts. It is even drawn on a sheet cut from the Bible. Why? Such an act might be deemed irreverent in a deeply religious man like the old man was, but when we piece the thing together we find that he was actuated by a religious spirit throughout. Not the least skilful part of his cryptogram is his concealment of the keyword in the text at the bottom. The text would convey nothing to most people, for very few people know anything about cryptograms, still fewer people would know that these texts contain the only two cryptograms in the Bible. Therefore, in accordance with his harmonious design, it seems to me that the keyword should be found in the five alternatives of the cryptic texts: Babel, Babylon, Sheshak, Remaliah, or Tabeal.
“Babel and Babylon may be discarded because there is no letter B in the cryptographic table, and it is essential that the keyword shall contain no letter which doesn’t also appear in the table. ‘Sheshak’ may also be discarded for the present as unlikely because of the awkwardness of the recurring ‘Sh’ in a keyword. There remain Tabeal and Remaliah. The tendency of the composer would be to use the longer word, because a long keyword is the better for the purpose. I think, therefore, we should first try whether Remaliah is the keyword we are in search of.”
“By Jove, Crewe, that is cleverly reasoned out!” exclaimed Marsland, in some excitement. “Let’s put it to the test. How do we apply this keyword to the table?”
“Easily enough. On this sheet of paper we will write down the cryptogram; and the keyword underneath it, letter for letter, thus:
| T | Y | N | M | V | R | T | T | H | S | M |
| R | E | M | A | L | I | A | H | R | E | M |
“Now, the first word of the cryptogram is T. Look in the first column of the table for it, and then run your eye across the table for the first letter of the keyword. When you have found it, look at the top of the column and tell me the letter.”
“K,” said Marsland.