"Perfectly," rejoined Warriner. "As usual, the truth lay in the middle distance. Now you go on, Betty; this is your part of the story."

"My part of the story!" echoed Betty deprecatingly. "I'm not an author; I'm merely the amanuensis, the typist, if you please."

"Mock modesty," proclaimed Warriner. "Even now we would still be standing before a closed door were it not for Betty and her master-key."

"Yes, my master-key," scoffed Betty. "Only it doesn't seem very clever of me to have carried it all these months without ever thinking to use it."

"Perhaps you couldn't find your pocket," suggested Chalmers.

"Enough of this bush-beating and persiflage," I commanded severely.

"Will you go on and tell me, Betty?"

"Well," began my wife obediently, "we had been warned away from the 'Hundred,' but you were obstinate and wouldn't budge; you had to be saved in spite of yourself.

"Of course I was right in going North immediately after the Midsummer Night's ball at 'Powersthorp.' Little Hugh really needed the change, and I wanted to be able to call at will on Chalmers for a.s.sistance in working out my problem. I couldn't do so if I stayed on at the 'Hundred,' even by means of correspondence. I don't suppose, Hugh, that I need to particularize any further in this direction?"

I mumbled something unintelligible, and, to add to my discomfiture, Warriner actually laughed. Never mind; I deserved it all.

"I could feel reasonably easy in my mind," went on Betty, "since I knew that the library had been dismantled and locked up. Besides, I had your solemn promise that you would not attempt to enter it for any purpose."

"I forgot," I murmured.

"That sounds like honest penitence, and I can forgive you--now. But I shall never be able to forget the afternoon your letter came with its calm announcement that you had been in the room to see about the damaged window; yes, and would probably have to go again.

"That letter reached Stockbridge at ten o'clock in the morning of Thursday, the twenty-first. Fifteen minutes later an express train left for New York, and Chalmers and I were the pa.s.sengers on it, leaving Hilda to follow with the nurse and the baby. At the first opportunity I sent you a telegram. Did you receive it?"

My thoughts went back to the yellow telegraphic sheet clutched in John Thaneford's black-knuckled hands, and held up before my helpless eyes.

"Yes, it came," I answered slowly, "but too late to be of any use."

"I was afraid of that," said Betty, "but we were leaving no stone unturned. We were missing connections all the way down, and I knew that the trap was ready for springing. And someone else knew it, too--John Thaneford."

"But," I objected, "Eunice expressly says that John Thaneford did not know the secret; except perhaps in part."

"What did he mean then by stupefying you with whiskey, and placing you, bound and helpless, in the big swivel-chair?" put in Warriner.

I was silent.

"Finally," continued Warriner, "it seemed certain that something had gone wrong with the working of the machinery, whatever it was. Whereupon he started for you--you remember--with bare hands."

Ah, yes, I remembered.

"Unquestionably, Thaneford was carrying out a perfectly definite plan of procedure. He knew what ought to have happened."

"But it didn't happen," I protested. "I'm here and very much alive."

"It did, and it didn't," retorted Warriner. "John Thaneford is dead."

"You mean--you mean----" I boggled.

"Yes, the Terror had entered the room; don't you recall how close I kept to the wall when I was trying to reach you? But it had become a blind Terror, and John Thaneford got in its way."

"But how and why?" I asked helplessly.

"Betty, it's your turn again," said Warriner, settling back in his chair.

Chapter XXI

_A Lost Clue_

"Suppose we admit, for the sake of argument," began Betty "that John Thaneford was in possession of the secret. Then everything points back to his father, old Fielding, who certainly had all the brains of the family. Last and most important, it was a secret which Mr. Thaneford, senior, desired to impart to me; he did tell me all he could."

"The series of numbers, you mean? I recall them perfectly: 1-4-2-4-8.

And what then?"

"Do you remember the story of Christian and his fellow pilgrim, Hopeful, imprisoned in Giant Despair's stronghold of Doubting Castle? After languishing for a week or more in darkness and misery, Hopeful suddenly bethinks him of a key which he has in his bosom, a key that will unlock any door in the castle. The rest is easy.

"So, too, I had my key, but I had only used it once--to unlock the first and most obvious door----"

"The combination of the safe," I interrupted.

"Precisely. It never occurred to either of us that it might be a master-key to which all locks must yield. But so it was.

"Not that I learned to use it without a lot of trouble and discouragement. It took months and months, and I only got it fully working on the train trip down from Stockbridge.

"Of course, you have guessed that the whole story lay buried in that leather-bound book belonging to Fielding Thaneford which we found in the safe. I remembered all that you had told me about 'Le Chiffre Indechiffrable,' but even granting that that particular cypher had been employed, how was I ever to stumble upon the indispensable key-word, or more likely, key-sentence?

"One day I had an inspiration. There was the series of numbers: 1-4-2-4-8. Considered as numbers merely they could be of no use, since most cypher codes are built up on letters. But I might put the numbers into their written word equivalents, thus: One-four-two-four-eight It was certainly conceivable that these letters might form the key-sentence; it would be all the more easily memorized since, in its numerical form, it served as a combination to the safe.

"I had with me the magic square which you had made for me, and I began very carefully to work out the problem according to your directions.

"The initial procedure was to put down my theoretical key-sentences, thus:"

O N E F O U R T W O F O U R E I G H T

"Underneath I must write the cypher message, and half a dozen letters would be enough to show if I were on the right track. I opened Mr.

Fielding Thaneford's old book, and copied down the first seven letters, ranging them vertically under the key-letters. That gave me this arrangement:"

O N E F O U R Q W O T T U I

"Now the rule goes on to say that you must find the letter O in the top horizontal column, and follow that column vertically downward until you come to the first cypher letter, in this case Q. The letter at the outside, left end of this second horizontal column, will be the first letter of the original message.

"Well, I tried it, and got the letter B. The next pair yielded an I, which was encouraging, as one would expect a vowel in this position. But the third try gave me a J, and that was not so promising; then I got an N and an E. So far my decoded message read: BIJNE; not very enlightening. The next pair showed the letter U in both key-sentence and cypher. Such a combination is impossible on our magic square, and I had to put down a blank s.p.a.ce. The final letter obtained was a Q, and the complete result read: BIJNE-Q. Pure gibberish of course. I tried out a few more pairs, and then gave up in disgust; my beautiful theory had fallen to pieces.

"Just the same, I wasn't ready to give it up. I knew, right in my bones, that old Mr. Thaneford had wanted to tell me something of supreme importance at that last moment on his deathbed, when my hand lay in his and I could feel the intermittent pressure of his fingers. It was impossible that I should be mistaken about any of the figures, for he went over the series three or four times; besides, they did open the safe.