Moreover, a yet more significant coincidence, the initials with which my letter had been signed, did they not stand for the words “Master of the World?” And whence came the second letter? “On Board the ‘Terror.’” Doubtless this name was that of the triple machine commanded by the mysterious captain. The initials in my letter were his own signature; and it was he who had threatened me, if I dared to renew my attempt on the Great Eyrie. I rose and took from my desk the letter of June thirteenth. I compared it with the facsimile in the newspapers. There was no doubt about it. They were both in the same peculiar hand-writing. My mind worked eagerly. I sought to trace the probable deductions from this striking fact, known only to myself. The man who had threatened me was the commander of this “Terror”—startling name, only too well justified! I asked myself if our search could not now be prosecuted under less vague conditions. Could we not now start our men upon a trail which would lead definitely to success? In short, what relation existed between the “Terror” and the Great Eyrie? What connection was there between the phenomena of the Blueridge Mountains, arid the no less phenomenal performances of the fantastic machine? I knew what my first step should be; and with the letter in my pocket, I hastened to police headquarters. Inquiring if Mr. Ward was within and receiving an affirmative reply, I hastened toward his door, and rapped upon it with unusual and perhaps unnecessary vigor. Upon his call to enter, I stepped eagerly into the room. The chief had spread before him the letter published in the papers, not a facsimile, but the original itself which had been deposited in the letter-box of the department. “You come as if you had important news, Strock?” “Judge for yourself, Mr. Ward;” and I drew from my pocket the letter with the initials. Mr. Ward took it, glanced at its face, and asked, “What is this?” “A letter signed only with initials, as you can see.” “And where was it posted?” “In Morganton, in North Carolina.” “When did you receive it?” “A month ago, the thirteenth of June.” “What did you think of it then?” “That it had been written as a joke.” “And now Strock?” “I think, what you will think, Mr. Ward, after you have studied it.” My chief turned to the letter again and read it carefully. “It is signed with three initials,” said he. “Yes, Mr. Ward, and those initials belong to the words, ‘Master of the World,’ in this facsimile.” “Of which this is the original,” responded Mr. Ward, taking it up. “It is quite evident,” I urged, “that the two letters are by the same hand.” “It seems so.” “You see what threats are made against me, to protect the Great Eyrie.” “Yes, the threat of death! But Strock, you have had this letter for a month. Why have you not shown it to me before?” “Because I attached no importance to it. Today, after the letter from the ‘Terror,’ it must be taken seriously.”