The latter appeared to be no longer in his former state of sardonic good nature. "Are you ready to tell us what you have done with the box?" he snarled.
Duvall made no reply, and this angered the doctor still further. "I'll give you an hour to think the matter over," he said, furiously. "And if you don't come to terms by that time, you shall stay under the influence of the light until you do." He turned toward the door, followed by Mayer, and in a moment they had left the room.
Duvall, in his pain and distress, realized that something would have to be done at once, within the next hour, in fact, or he would be obliged to give up. Physical torture he could stand, but to lie here silently, under that cruel radiance, and realize that his brain was slowly giving way, he felt he could not endure.
Yet what was there that he could do? The walls of the room, of solid brick, he could not hope to penetrate. The door, of iron, a dozen men could not break through. He forced his shoulder against it, and laughed bitterly as he realized that with all his strength he could not even cause it to give the fraction of an inch. He determined to get the snuff box—to examine it—reckless of his fear of being observed. In a moment he had snatched the opera hat from the corner, torn out the lining, and held the box in his hand.
He paused for a moment, listening intently. Everything about him was still. There were no sounds from the laboratory above. He remembered now that he had not heard Hartmann and his companion ascend the iron stairway. Doubtless they had returned to the main building by means of the lower corridor.
In a moment he had hung the torn opera hat over the knob of the door, to prevent anyone from observing him through the keyhole, and going directly beneath the bracket which held the electric globe, proceeded to examine the box carefully.
The first thought that came to his mind, filled him with a strange feeling of hope. He had no more than glanced at the top of the box when he saw what he had previously failed to observe, that the circle of pearls upon its top formed a rosary, which was completed by the ivory cross in the center. The Rosary! Why had this song been so persistently and continuously played? Was it for him, some message, indeed, intended to show him a way out of his difficulties? Yet if so, to what did it lead? There was a rosary upon the top of the box, it is true, but what of it? Absently he began to count the pearls, hardly realizing what he was doing. One of them, he noted, the one at the very top of the cross, was larger than the others, and he started here, slowly counting around the circumference of the box. His eyes pained him frightfully and twice he lost count and had to begin all over again, but on the third attempt he discovered that the pearls numbered twenty-six. Even yet, the significance of this fact did not occur to him—he began to count the pearls again, mechanically.
Then suddenly, in a flash, the thing came to him. Twenty-six pearls—twenty-six letters in the alphabet. Evidently the box, in some way, formed a cipher, a secret alphabet, which might be used in correspondence, or in the preparation of important documents, yet how—how?
With repressed eagerness he held the box more closely to the light, searching its surface for some further clue. At once he noticed the arrangement of the concentric circles of letters which made up the Latin prayer. The words were so written that each letter stood opposite a pearl, and reading inward from each pearl, there was a row of letters six deep reaching almost to the center of the box. Clearly here were six different ciphers, that is, six circles of twenty-six letters each, any one of which might constitute a working cipher. It was only necessary to call the big pearl at the top "A," and here were six different letters opposite it, any one of which, in a system of cipher writing, might be used as the letter A.
Duvall, however, knew enough about ciphers to know that such an arrangement constituted no cipher at all, in other words, that ciphers so simple, so readily solved, as this, would never be employed in any case where absolute secrecy was imperative. He felt that there was something more to the matter than he had so far discovered.