“But I don’t quite understand how you arrived at the key, dad?” she said. “Explain to me, for, as you know, I’m all curiosity.”

“Well, as you don’t know Hebrew, dear, I’ll try and explain it as clearly as I can,” he said. “Each Hebrew letter has its own numerical value, as you know, A-leph representing 1, Bêth 2, Gi-mel 3, and so on to Yodh 10, and the nine tens to 100, or Qoph, to 400, represented by the last of the twenty-two consonants, Tâw. The fact that Holmboe mentioned ‘wāw,’ or the number 6, in his manuscript, first caused me to believe that he did so as a blind, because this also signified ‘hook’ and was the sign of evil. I applied it diligently in nearly two hundred places in the Book of Ezekiel, but without a single success. I used other numbers, indeed most of the combinations of the twenty-two consonants, especially the one of three and thirty-three which was one of the earliest numerical ciphers. You know well how diligently I worked, and how unsuccessful I have been until to-day.”

“I know, dad,” exclaimed the pretty girl, “but I confess I can hardly follow you, even now.”

“Well, listen,” he said. “The Apocalyptic Number is 666, and its interpretation rests upon the fact that in Hebrew, as well as in Greek, the letters of the alphabet did service for numbers. Hence, a writer, while avoiding a direct mention of some person or thing, could yet indicate the same by a number which was the sum of the various values comprising the name. First establishing the point where the actual message commences, which I may as well explain is at Ezekiel, x, 8; ‘And there appeared in the cherubim the form of a man’s hand under their wings,’ I took the first ‘wāw’ or 6 sign, then the eleventh letter, being the sixth of sixty-six, then the sixty-sixth letter, and afterwards the six hundred and sixty-sixth letter. Following this, I made the additions which are known to the Greeks and also to the Hebrews, working it out thus: The fiftieth letter, the two-hundredth letter, the sixth letter, the fiftieth letter, the hundredth letter, the sixtieth letter and the two-hundredth letter—making in all six hundred and sixty-six. The Hebrew signs of each I wrote down in a line, and having divided them into words, I found to my amazement, that I was reading the secret record alleged by the dead professor!”

“But, surely, dad, that is a most ingenious cipher!” remarked his daughter.

“Most intricate, I assure you. By sheer good fortune I discovered the starting-point.”

“What led you to it?”

“A slight, almost unnoticeable deviation of the present Hebrew text from the St. Petersburg codex. I had never before noticed it, and it only arrested my attention because I was studying the subject so very closely.”

“And after making the additions of 666, how did you proceed?” urged the girl.

He paused for a few seconds as though in hesitation.