Grace had remained upon her knees beside the prostrate figure of her husband but a moment, when she was torn away by Hartmann and his assistant, and before she realized their intention, the former had slipped about her waist the broad leather strap he had brought from the room above, and was busy securing it to an iron staple fixed in the wall at one side of the room. Then he stood back and surveyed the scene with a smile of satisfaction.

"You see, Mayer," he observed, grimly, "my purpose. The wife sees the husband's suffering. If he refuses to speak, she will speak. One or the other will tell us what we want to know, of that you may be sure. Let us leave them to talk matters over." He and his man at once left the room, and in a few moments Grace heard their footsteps upon the floor of the laboratory above.

"Richard," she cried, softly, "are you suffering very much?"

"Never mind, dear," he said, trying vainly to turn his head so that he might see her. "What has happened—why have they brought you here?"

She told him her story, brokenly, with many sobs. "I could not help it, Richard," she moaned. "I did my best. I could not help their finding out everything."

"I know it, dear. You have done all you could. Is there any news from outside?"

"None. They told me to play the phonograph to send you a message. Did you hear it?"

"Yes, I heard, and understood."

"Understood? Then you know something—you have some hope?"

"I do not know. It may be, although I cannot see what to do now. I dare not tell you more than that—these scoundrels are undoubtedly listening in the room above."

"Richard, what is that light? What is it they mean to do to you? Dr. Hartmann showed me his hand—it was all scarred and burned. He said it came from that." She looked toward the glowing cone of light with bitter anger.

"I do not know—exactly. I am not sure. The agony of the thing is very great—it burns into my eyes—into my brain. Hartmann says it will produce insanity. I do not know whether this is true or not. I begin to feel that perhaps it may be—not that the light itself can produce it, but that inability to sleep, pain, nervous exhaustion, the constant glare and brilliance before my eyes—those things might cause a man to go insane, if they were kept up long enough."

"But—he—he will not dare to do that."

Duvall groaned, striving in vain to turn his head to one side. "He intends to keep me here, until I tell him where he can find the snuff box," he gasped.

"Richard!" Grace fairly screamed out his name. "Then you must tell—you must! You cannot let yourself go mad—not even for Monsieur Lefevre."

"I shall not tell—no matter what comes," he replied.

"Then I will. I refuse to let you suffer like this. I can't do it, I won't. If you do not speak, I shall. Oh, my God! Don't you see—I love you—I love you so—what do I care about this foolish snuff box? I want you—you—and I won't let them take you away from me."

"Grace, you shall not tell them."

"I will."

"I forbid it."

"I cannot help it, Richard. I am ready to disobey you—if I must, to save your life. Even if you turn from me—afterward—I cannot help it. I refuse to let them go ahead with this thing."

He groaned in desperation. "Please—please—my girl—listen to me. You must not speak. We must think of our duty to those who have trusted us. Wait, I implore you. Don't do this!"

"I will. I have a duty to you which is greater than my duty to them. Dr. Hartmann!" she screamed. "I will tell everything—everything." She collapsed against the wall and sobbed as though her heart would break.

In a few moments they heard Hartmann and Mayer descending the steps, and the door was thrown open.

"Ah, so you have come to your senses, have you?" the doctor cried. "Well, what have you to say?"

Grace raised her head. "If I tell you where the ivory snuff box is hidden," she said, "will you let my husband go?"

"Yes. Your husband, and yourself, and the rat we've just caught sneaking around outside. He's up in the laboratory now. You can all take yourselves off as quickly as you like, when once the snuff box is in my hands. Now speak."

"First, let my husband up."

Hartmann went to the wall, and switching off the violet rays, turned on the electric lamp, then nodded to Mayer. "Unbind him," he said.

Duvall staggered to his feet, half-blinded. As he did so, Hartmann turned to Grace. "Speak!" he commanded. "We are wasting time."

Before Grace could reply, Duvall turned to her.

"I forbid you," he cried. "If you do this thing, I will never see you again as long as I live. You are destroying my honor. I refuse to let you do it. Stop!"

The girl hesitated, and Hartmann swore a great oath. "Take her out of here, Mayer," he cried. "She'll never speak, as long as her husband is present to dissuade her. Up with her to the laboratory. She'll talk there, quick enough."

"No!" Duvall staggered toward her. "You shall not." His movements were slow and uncertain, due to the blinding pain in his eyes, and his stiffened, nerve-racked limbs. Hartmann pushed him aside angrily. "Be quiet," he growled. "Let the woman alone."

Meanwhile Hartmann's companion had torn away the strap which bound Grace to the wall and was leading her to the door. Her husband's efforts to detain her, weak and uncertain, were easily frustrated by Hartmann. In a few moments the door had swung shut upon the detective, and she was being led up the steps to the room above.

Here she fell into a chair, and looking about, saw huddled on a couch in the far corner of the room a little, bent old man, who sat with his white head bowed upon his breast, his hands tied behind his back. Hartmann went over to him and unfastened his bonds. "You will be happier in a moment, my friend," he laughed. "This lady is going to set you free."

Dufrenne—for it was he—sprang to his feet. "How?" he demanded. "How?" As he spoke, he crossed the room, his eyes gleaming, and faced Grace as she sat in the chair.

"Wait and see, old man," said Hartmann, roughly. "Stand aside, please." He pushed Dufrenne impatiently away. "Now, young woman, where is the ivory snuff box?"

Grace raised her head to reply, when the little old Frenchman turned to her, pale with anger. "No!" he shouted, starting forward. "You shall not do this thing. Would you be a traitor to France!"

Grace looked at him and shuddered. His face was quivering with emotion—his eyes burned with piercing brightness, he seemed about to spring at her, in his rage. In a moment Hartmann had turned on him. "Be quiet!" he roared. "I want no interference from you. Mayer!" He pointed a trembling forefinger at the old Frenchman. "Take this fellow away."

Mayer took Dufrenne by the arm and twisted it cruelly. "No nonsense, now!" he growled, thrusting the old man toward the couch upon which he had been sitting. "Hold your tongue, or it will be worse for you." Dufrenne resisted him as best he could, but his age and feebleness rendered him helpless. He sank upon the couch, with tears of anger starting to his eyes.

Grace dared not look at him. The enormity of the thing she was about to do appalled her. Yet there was Richard, her husband; Richard, whom she loved with all her soul, in the room below, facing madness, death. The love she felt for him overmastered all other considerations. She turned to Hartmann with quivering face. "The box is in the room below," she cried, in a voice shaking with emotion.

"Mon Dieu—mon Dieu!" she heard Dufrenne gasp, as he started from the couch. "You have ruined us all."

Hartmann and Mayer gazed at each other incredulously. "Impossible!" the former gasped. "Impossible!" Then he turned to Grace. "Girl, are you telling me the truth?"

She nodded, bowing her head upon her hands. She could not trust herself to speak.

"Where? Where in that room could it be hidden? Tell me!" he shook her angrily by the arm. "Haven't we wasted enough time over this thing?"

Still she made no reply. Now that she had told them, a sudden revulsion swept over her. She hated herself for what she had done, hated Hartmann, hated Monsieur Lefevre for placing her in this cruel situation.

Hartmann dragged her roughly to her feet. "If the box is in the room below, come with me and find it."

He hurried her toward the staircase. "Come along, Mayer," he called over his shoulder. "Bring that fellow with you. It won't be safe to leave him." As she descended the steps, Grace heard the other two close behind her. The Frenchman staggered along like a man in a daze, offering no resistance.

When they burst into the room in which Duvall was confined, they found the latter standing beneath the electric lamp, a look of determination upon his face. He regarded them steadily, in spite of his reddened and burning eyes.

Hartmann paid little attention to him. He was too greatly interested in the movements of Grace. "Now," he said, "where is it? You say the snuff box is here—in this room. Find it."

She hesitated, looking at her husband pitifully. What would he think of her? Would he, too, regard her as a traitor, a weak and contemptible creature, forever barred from love and respect, false to her duty, her honor? His face told her nothing. He was regarding her impassively. She remembered now that he had said that he would never see her again if she disobeyed him. Then she turned away, her mind made up. She would save him, come what might. He had told her that the box was hidden in an opera hat, in one corner of the room. She glanced about quickly, trying to discover its whereabouts in one of the dark corners.

Duvall saw her intention. He took a step forward, and addressed Hartmann. "You have forced this girl, through her love for me, to betray a great trust. I prefer that, if anyone here is to become a traitor, it shall be myself." He thrust his hand into the pocket of his coat, and extended a round white object toward the astonished doctor. "Here is the snuff box."

Dufrenne, for the moment left unguarded by Mayer, sprang forward with a fierce cry. "No—no—no!" he screamed. "You shall not—you shall not."

"Out of my way!" exclaimed the doctor, brushing the old man aside as easily as though the latter had been a child. With eager hands he took the box, and going to the light, bent over it. As he saw the pearls, the cross, his face lit up with delight. "This is it, Mayer. Just as the valet described it." He gave the ring of pearls a swift turn, then pressed immediately upon the larger one of the circle and slid the top of the ivory cross to one side. Duvall, who was watching him with interest, concluded that from some source, probably through Monsieur de Grissac's dead servant, Dr. Hartmann had learned thoroughly the secret of the box.

With a cry of satisfaction the latter drew out from the tiny recess the slip of folded paper, glanced at the row of numbers written upon it, then passed it over to Mayer. The latter nodded his head. "Now we are all right," he muttered. "This is easily worth a million francs."

"Money doesn't measure its value, my friend," the doctor remarked, gravely, as he replaced the slip of paper beneath the cross and put the box carefully into his pocket.

During these few moments, Dufrenne had been observing the doctor with bulging eyes. Suddenly he turned on the detective. "May the good God curse you and your woman for this," he cried, hoarsely, "until the day of your death. May He turn all men against you, and make your name a despised and dishonored one forever. You have been false to your duty—false to France. You are a traitor, a contemptible dog of a traitor, and you deserve to die." His whole body shook with passion as he poured the fury of his wrath upon the man before him.

Duvall sank weakly against the packing case behind him. Suffering, lack of sleep and food, the burning pain in his eyes and brain, threatened to overcome him. "Let me alone," he gasped. "I am so tired, so very tired!" He almost fell as he uttered the words and indeed would have done so had Grace not gone quickly up to him and passed her arm lovingly about his shoulders. Turning to Dufrenne, she regarded him with a look of defiance. "He is not guilty!" she cried. "It is I—I!—who have been false. I made him do it—I made him do it. Go away, and tell the others what you please. I know that my husband has done his best." She fell to soothing him, kissing him upon his hot forehead, his burning cheeks.

Dufrenne looked at Dr. Hartmann, who was regarding the scene before him with impatience. "Do I understand, monsieur," he asked, in a ghastly voice, "that I am free to leave this place?"

"Yes. Out with you. I could hold you for trespass upon my grounds, for attempting to break into my house, but I don't want to be bothered with you. Go!" He went to the door and held it open. "Mayer," he said, "show this fellow the road. And as for you"—he turned to Duvall and his wife—"get away from here, and from Brussels, as soon as you like. I advise you not to stay in the town. I rather think that, through the evidence of Seltz, I can make it slightly uncomfortable for you. Tell what story you please. I have done you no injury. You came here of your own free will—you could have escaped and you would not. As for the light—" He laughed harshly. "An ordinary arc, focused on your eyes with a powerful lens. It would probably have blinded you, in time, and if it kept you awake long enough, you would no doubt have gone mad, but so far you are not hurt much. I can swear that it is part of my new treatment for a disordered mental state. My man here will agree with me. What are you going to do about it? How are you going to explain your robbery of Seltz in my office, the deception your wife has practised upon me and upon the United States Minister? And above all, now that I have the secret I desired, I am quite willing to have a cast made of the snuff box and return it to you, but I fancy that neither Monsieur de Grissac nor my friend Lefevre will want to have the matter made public in the courts. You'd better leave here quietly and take the first steamer to America. I don't fancy you'll find a very flattering reception awaiting you in Paris." He turned to the door. "Come, I'll have your belongings put on a cab, and be glad to be rid of you." He paused beside the doorway, waiting.

Grace turned to her husband. "Come, Richard," she said. "Let us go."

He made no reply, but followed her blindly. His spirits seemed broken, he walked like a man in a heavy sleep.

It was just dawn when, half an hour later, Richard Duvall and his wife drove silently through the ghostly streets of Brussels toward the railway station. The detective did not speak. He sat silent, plunged in a deep stupor. Grace, her heart breaking, held one of his hands, and with white face, gazed helplessly out of the window at the city, just waking to another day. To all these people the dawn came with some measure of hope, of happiness, but to her, and to her husband, now once more beginning their honeymoon, the future seemed full of bitterness and despair. She shivered in the cold morning air, and the tears she could not repress stole unheeded down her cheeks.