Pat emitted a small, startled shriek, and heard it echoed by a surprised grunt from Dr. Horker.

"Queer!" he muttered. "The stuff must be mislabeled. Scopolamine doesn't act like this; it's a narcotic."

"He's—the other!" gasped Pat, while the being on the couch grinned sardonically.

"Eh? An attack? Can't be!" The Doctor shook his head emphatically.

"It's not Nick!" cried the girl in panic. "You're not, are you?" she appealed to the grim entity.

"Not your sweetheart?" queried the creature, still with his mocking leer. "A few hours ago you were lying here all but naked, confessing you were mine. Have you forgotten?"

She shuddered at the reference, and shrank back in her chair. She heard the Doctor's ominous, angry rumble, and the evil tittering chuckle of the other.

"Pathological or not," snapped Horker, "I can resent your remarks! I've considered several times varying my treatment with another solid cut to the jaw!" He rose from his chair, stamping viciously toward the other.

"A moment," said Nicholas Devine. "Do you know what you've done? Have you any idea what you've done?" He turned cool, mocking, red-glinting eyes on the Doctor.

"Huh?" Horker paused as if puzzled. "What I've done? What do you mean?"

"You don't know, then." The other gave a satyric smile. "You're stupid; I gave you the clue, yet you hadn't the intelligence to follow it. Do you know what I am?" He leaned forward, his eyes leering evilly into the Doctor's. "I'll tell you. I'm a question of synapses. That's all—merely a question of synapses!" He tittered again, horribly. "It still means nothing to you, doesn't it, Doctor?"

"I'll show you what it means!" Horker clenched a massive fist and strode toward the figure, whose eyes stared, steadily, unwinkingly into his own.

"Back!" the being snapped as the great form bent over him. The Doctor paused as if struck rigid, his arm and heavy fist drawn back like the conventional fighting pose of a boxer. "Go back!" repeated the other, rising. Pat whimpered in abject terror as she heard Horker's surprised grunt, and saw him recede slowly, and finally sink into his chair. His bewildered eyes were still fixed on those of Nicholas Devine.

"I'll tell you what you've done!" said the strange being. "You've freed me! There was nothing wrong with your scopolamine. It worked!" He chuckled. "You drugged him and freed me!"

Horker managed a questioning grunt.

"I'm free!" exulted the other. "For the first time I haven't him to fight! He's here, but helpless to oppose me—he's feeble—feeble!" He gave again the horrible tittering chuckle. "See how weak the two of you are against my unopposed powers!" he jeered. "Weaklings—food for my pleasures!"

He turned his eyes, luminous and avid, on Pat. "This time," he said, "there'll be no interruptions. A witness to our experiment will add a delicate touch of pleasure—"

He broke off at the Doctor's sudden movement. Horker had snatched a glistening blue revolver from his pocket, held it leveled at the lust-filled eyes.

"Huh!" growled the Doctor triumphantly. "Do you think I come trailing a maniac without some protection? Especially a vicious one like you?"

Nicholas Devine turned his eyes on his opponent. He stared long and intently.

"Drop it!" he commanded at length. Pat felt a surge of chaotic terror as the weapon clattered to the floor. She turned a frightened glance on Horker's face, and her fright redoubled at the sight of his straining jaw, the perspiration-beaded forehead, and his bewildered eyes. The demon kicked the gun carelessly aside.

"Puerile!" he said contemptuously. He backed away from them, re-seating himself on the couch whence he had risen. He surveyed the pair in sardonic mirth.

"Pat!" muttered the Doctor huskily. "Get out of here, Honey! He's got some hellish trick of fascination that's paralyzed me. Get out and get help!"

The girl moved as if to rise. Nicholas Devine shifted his eyes for the barest instant to her face; she felt the strength drain out of her body, and she sank weakly to her chair.

"It's useless," she murmured hopelessly to the Doctor. "He's—he's just what I told you—a devil!"

"I guess you were right," mumbled Horker dazedly.

There was a burst of demonic mirth from the being on the couch. "Merely a matter of synapses," he rasped, chuckling. His face changed, took on the familiar coldness, the stony expression Pat had observed there before. "This palls!" he snapped. "I've better amusement—after we've rendered your friend merely an interested on-looker." He narrowed his red eyes as if in thought. "Take off a stocking," he ordered. "Tie his hands to the back of the chair."

"I won't!" said the girl. The eyes shifted to her face. "I won't!" she repeated tremulously as she kicked off a diminutive pump. She shuddered at the gleam in the evil eyes as she stripped the long silken sheath from a white, rounded limb. She slipped a bare foot into the pump and moved reluctantly behind the chair that held the groaning Horker. She took one of the clenched, straining hands, and drew it back, fumbling with shaking fingers as she twisted the strip of thin chiffon. The demon moved closer, standing over her.

"Loose knots!" he snarled abruptly. He knocked her violently away with a stinging slap across her cheek, and seized the strip in his own hands. He drew the binding tight, twisting it about the lowest rung of the chair's ladder back. Horker was forced to lean awkwardly to the rear; in this unbalanced position it was quite impossible to rise.

Nicholas Devine turned away from the straining, perspiring Doctor, and advanced toward Pat, who cowered against the shattered cabinet.

"Now!" he muttered. "The experiment!" He chuckled raspingly. "What delicacy of degradation! Your lover and your guardian angel—both helpless watchers! Excellent! Oh, very excellent!"

He grasped her wrist, drawing her after him to the center of the room, into the full view of the horrified, staring eyes of Horker.

"Always before," continued her tormentor, "these hands have prepared you for the rites—the ceremony that failed on two other occasions to transpire. Would it add a poignancy to the torture if I made you strip this body of yours with your own hands? Or will they suffer more watching me? Which do you think?"

Pat closed her eyes in helpless resignation to her fate. "Nick!" she moaned. "Oh, Nick dearest!"

"Not this time!" sneered the other. "Your friend and protector, the Doctor, has thoughtfully eliminated your sweetheart as a factor. He struggles too feebly for me to feel."

"Nick!" she murmured again. "Dr. Carl!"

But the Doctor, now pulling painfully at his bonds, could only groan in distraction, and curse the unsuspected strength of sheer chiffon. He writhed miserably at the chafing of his wrists; his strange paralysis had departed, but he was quite helpless to assist Pat.

"I think," said the cold tones of Nicholas Devine, "that the more delicate torture lies in your willingness. Let us see."

He drew her into his arms. He twisted a hand in her hair, jerked her head violently backward, and pressed avid lips to hers. She struggled a little, but hopelessly, automatically. At last she lay quite passive, quite motionless, supported by his arms, and making not the slightest response to his kiss.

"Are you mine?" he queried fiercely, releasing her lips. "Are you mine now?"

She shook her head without opening her eyes. "No," she said dully. "Not now, or ever."

Again he crushed her, while the Doctor looked on in helpless, bewildered, voiceless anger. This time his kiss was painful, burning, searing. Again that unholy fascination and unnatural delight in her own pain stirred her, and it took what little effort she was able to make to keep from responding. After a long interval, his lips again withdrew.

"Are you mine?" he repeated. She made no answer; she was gasping, and tears glistened under her closed eye-lids, from the pain of her crushed lips. Again he kissed her, and again the wild abandonment to evil suffused her. She was suddenly responding to his agonizing caress; she was clinging fiercely to his torturing lips, feeling an unholy exaltation in the pain of his tearing fingers in the flesh of her back.

"Yours!" she murmured in response to his query. She heard her voice repeat madly, "Yours! Yours! Yours!"

"Do you yield willingly?" came the icy tones of the demon.

"Yes—yes—yes! Willingly!"

"Take off your clothes!" sounded the terrible, overpowering voice. He thrust her from him, so that she staggered dizzily backward. She stood swaying; the voice repeated its command.

The girl's eyes widened wildly; she had the appearance of one in an ecstasy, a religious fervor. She raised her hand with a jerky impulsive gesture to the neck of her frock, still pinned together in the makeshift repairs of the evening.

There came a strange interruption. The Doctor, helpless on-looker, had at length evolved an idea out of the bewilderment in his mind. He opened his mouth and emitted a tremendous, deep, ear-shattering bellow!

Nicholas Devine sent the girl spinning to the floor with a vicious shove, and turned his blazing eyes on Horker, who was drawing in his breath for a repetition of his roar. "Quiet!" he rasped, his red orbs boring down at the other. "Quiet, or I'll muffle you!" Closing his eyes, the Doctor repeated his mighty shout.

The demon snatched the blanket from the couch, tossing it over the figure of the Doctor, where it became a billowing, writhing heap of brown wool. He turned his gaze on Pat, who was just struggling to her feet, and moved as if to advance toward her.

He paused. She had retrieved the Doctor's revolver from the floor, and now faced him with the madness gone out of her eyes, supporting the weapon with both hands, the muzzle wavering toward his face.

"Drop it!" he commanded. She felt a recurrence of fascination, and an impulse to obey. Out of the corner of her eye, she saw the Doctor's head emerging from the blanket as he shook it off.

"Drop it!" repeated Nicholas Devine.

She closed her eyes, shutting out the vision of his dominant visage. With a surge of terror, she squeezed the trigger, staggering back to the couch at the roar and the recoil.

She opened her eyes. Nicholas Devine lay in the center of the room on his face; a crimson spot was matting the hair on the back of his head. She saw the Doctor raise a free hand; he was working clear of his bonds.

"Pat!" he said softly. He looked at her pale, sickened features. "Honey," he said, "sit down till I get free. Sit down, Pat; you look faint."

"Never faint!" murmured the girl, and pitched backward to the couch, with one clad and one bare leg hanging in curious limpness over the edge.