"On the head of this pin is engraved a series of letters which form a cipher message telling of the hiding-place of your aunt's jewels." "On the head of that little pin! Impossible!" "It does seem impossible, but I assure you that on the surface of the head of this pin there are thirty-nine letters, which, meaningless in themselves, form a cipher statement. If we can solve their message----" "If we _can_!" cried Iris. "We _must_!" "You bet Mr. Stone will work it out, if it's a cipher," Fibsy declared, looking with pride and confidence at his employer's face. "Not so easy, Fibs," Stone returned. "It's a cryptogram which necessitates another bit of information, a keyword, before it can possibly be solved. By the way, Miss Clyde, that's what your aunt's diary means by its reference to the jewels being hidden in a crypt. If you read her diary carefully, you'll see that she very frequently abbreviates her words, not only Tues., for Tuesday, and Dec., for December, but other words, just as the whim took her. So, as we may conclude, the word crypt stands for cryptogram. And here's the cryptogram. Now, to explain this seemingly miraculous feat of engraving thirty-nine letters on the head of an ordinary pin, I'll say that it is not an unheard-of accomplishment. Several years ago, I saw on exhibition a pin with forty-five letters to it, and I have seen one or two other similar marvels. They are done, in every instance, by a most expert engraver, who has much time and infinite patience and capacity for carefulness. Indeed, it is an art all by itself, and I doubt if there are many people in the world who could accomplish it at all." "Can you show them to me?" Iris asked, her eyes wide with wonder. "Oh, yes, you can see them with this glass, though even with its aid you may have difficulty in making out the letters." Iris looked long and carefully through the powerful lens, and finally declared that she could discern the letters, but could not read them clearly. Stone passed the pin and glass to Miss Darrel, and continued, "I spent nearly the whole night over it. I have copied off the letters, so now, if the pin should be stolen, at least we have its secret. Though, I confess the secret is still a secret." "Lemme see it," begged Fibsy, as Miss Darrel gave up the effort to make out the letters at all. The younger eyes of the boy read them with comparative ease. "O, I, N, V, L, D, L," he spelled out "Sounds like gibberish, but all ciphers do that--why, Mr. Stone, the letters are clear enough and you can read any cipher that ever was made up, I'll bet! You know, you first see what letter's used most, and that's E----" "Hold on, Terence, not so fast. That's one kind of a cipher, to be sure. But this is another sort. These are the letters: "O I N V L D L Q P S V T H P J R C R N O X X I V B A Y O D I J Y A W W K M E U "There's no division into words, which, of course, makes it infinitely more difficult."