Throughout all these torturing thoughts, the figure of Grace came and went unceasingly. What would she do—what could she do, to aid him? He had warned her not to ask Mr. Phelps to take any steps looking to his release. He realized that were Hartmann to appear now, and give him his freedom, he would not dare to accept it. That the doctor might do this very thing was his greatest fear. If he should insist upon his leaving the place, what could he do, then, to recover Monsieur de Grissac's snuff box? He prayed fervently that Dufrenne and his companions might in some way work out a plan to set matters right.
Presently he fell to thinking of the snuff box, and its safety. How fortunate it seemed, that the doctor and his man Mayer had overlooked the opera hat. He wondered if they had thought of it since? It was clear that they had not, else he would no longer be kept a prisoner. What was the room beneath the laboratory used for? Its appearance had suggested that it was not used at all—a mere lumber-room, a place for storing boxes and crates. And then there flashed into his mind the thought, where was he now? From the apparent distance of the ceiling, as shown by the beam of light, he concluded that he was lying on the floor, a conclusion which the hardness and coldness of the surface beneath him amply proved. Evidently it was a floor of stone, or cement, not one of wood. A certain sense of familiarity in his surroundings came over him. The faint radiance which was diffused about him by the light cone showed the walls before and on either side of him to be of uniform blackness, unrelieved by any suggestion of windows. He strove with all his power to pierce the shadowy gloom, to come upon some point of recognition, but the darkness baffled him.
In one corner a huge shadow, bulking formless against the wall, suggested the packing case behind which his opera hat had been tossed by Mayer during the search the night before. The thought thrilled him with renewed hope. What more likely place, after all, for Hartmann's deviltries than this silent room beneath the laboratory? If he was lying there now, and chance of escape should come, he might even yet be able to take the missing snuff box with him.
The hours dragged interminably. He was conscious of a keen feeling of pain, a smarting irritation, in his eyes, which caused tiny streams of moisture to trickle beneath their lids and roll unheeded down his cheeks. The muscles of his neck became sore and swollen, from his incessant though useless effort to turn aside his head. A dull pain began to shoot insistently through his temples, and his limbs became numb and cold. The desire to escape from the relentless brilliance of the light cone became unbearable; he felt as though, if relief did not soon come, he would shriek out in a madness of terror. Then the hopelessness of doing so became apparent, and he nerved himself with all the power of his will to endure the ever-increasing torture. Yet this torture was, he knew, largely mental—the actual pain was by no means unbearable; it was only the dull, insistent pounding of the light rays upon his eyes, his brain, from which he longed to escape. With closed eyes and tensely drawn nerves, he waited, watching the endless play of the tracery of light in the dull redness of his eyelids.
The sudden sharp rattle of a key in the door, followed by the turning of the knob, told him that someone was entering the room. He had a momentary vision of a patch of light, yellow against the surrounding blackness, which disappeared almost instantly as the door was closed. Then he was conscious of a shadowy form beside him, and heard the smooth, modulated tones of Dr. Hartmann's voice.
"Well, Mr. Duvall," he said, "how goes the treatment? Memory any better this morning?"
He made no reply. The mockery in the doctor's voice roused him to sudden and bitter anger.
"I'm trying a new modification of the light treatment upon you," Hartmann went on, with a jarring laugh. "Dr. Mentone, of Milan, has great hopes of it. Wonderful thing, these violet rays! Have you read of their use in sterilizing milk? No? The subject would interest you. How is your mind this morning? Somewhat irritated, no doubt. Well, well, that will soon wear off. You've only been under the treatment six hours. Scarcely long enough to produce much effect. We'll make it ten, the next time. It is necessary to increase gradually, in order not to superinduce insanity." He went to a switch on the wall and pressed it, and instantly the cone of light disappeared. Another movement, and the room Was flooded with the yellow glow of an electric lamp, which seemed dingy and wan, compared with the cold brilliance which it displaced.
The dispelling of darkness brought to Duvall's brain a rush of sensations, among which the knowledge that he was once more in the lumber-room beneath the laboratory stood forth with overwhelming prominence. He glanced at Hartmann with reddened eyes. "Let me up, damn you!" he shouted.
The doctor bent over him, his face smiling. "Just a moment, Mr. Duvall. Have a little patience." He began to unbuckle several straps, and presently stood back, with a wave of his hand. "Get up," he said.