Afaint whirring noise attracted his attention, and he could see the faintly luminous globe in the distance, rapidly approaching. It came to a stop at the spot where it had previously landed and four men got out. Instead of going toward the cave, they towed the globe, which floated a few inches from the earth, toward the side of the hill farthest from where the doctor stood. Three of them held it, while the fourth went forward and bent over some controls on the ground. A creaking sound came through the night and the men moved forward with the globe. Presently its movement stopped and men reappeared. Again came the creaking sound and the glow faded out as though a screen had been drawn in front of it. The four men walked toward the door of the cave.
Dr. Bird dropped flat on the ground and saw them pause a few yards below him on the hill and again work some hidden controls. A glare of light showed for an instant and they disappeared and everything was again quiet. Dr. Bird debated the advisability of returning to the window but decided against it and moved down the face of the hill.
Inch by inch he went over the ground, but found nothing. In the darkness he could not locate the door and he made his way around to the back of the hill. The precipice loomed above him and he swept it with his gaze, but he could locate no opening in the darkness and he dared not use a flash-light. As he turned he faced the east and noted with a start of surprise that the sky was getting red. He glanced at his watch and found that Carnes had been gone for nearly three hours.
"Great Scott!" he exclaimed in surprise. "Time has gone faster than I realized. He ought to be back at any time now."
He mounted the highest point of the hill and sent three long flashes, followed in turn by three short and three more long to the south and watched eagerly for an answer. He waited five minutes and repeated the signal, but no answering flashes came from the empty hills. With a grunt which might have meant anything, he turned and made his way toward the opposite side of the hollow where the globe had disappeared. Here he met with more luck. He had marked the location with extreme care and he had not spent over twenty minutes feeling over the ground before his hand encountered a bit of metal. As he pulled on it his eyes sought the side of the hill.
The dawn had grown sufficiently bright for him to see the result of his action. A portion of the hill folded back and the faintly glowing ship became visible. With a muttered exclamation of triumph he approached it.
The globe was about nine feet in diameter and was without visible doors or windows. Around and around it the doctor went, searching for an entrance. The ship now rested solidly on the ground. He failed to find what he sought and his sensitive hands began to go over it searching for an irregularity. He had covered nearly half of it before his finger found a hidden button and pressed it. Silently a door in the side of the craft opened and he advanced to enter.
"Keep them up!" said a sharp voice behind him.
Dr. Bird froze into instant immobility and the voice spoke again.
"Turn around!"
Dr. Bird turned and looked full into the eye of a revolver held by the man the dwarf had addressed as Frink. Behind Frink stood the dwarf and three other men.
As his eye fell on Dr. Bird, Frink turned momentarily pale and staggered back, the revolver wavering as he did so. Dr. Bird made a lightning-like grab for his own weapon, but before he could draw it Frink had recovered and the revolver was again steady.
"Dr. Bird!" gasped Slavatsky. "Impossible!"
"Get his gun, Harris," said Frink.
One of the men stepped forward and dextrously removed the doctor's automatic and frisked him expertly to insure himself that he had no other weapon concealed.
"Bring him to the cave," directed Slavatsky, who, though obviously still shaken, had just as obviously recovered enough to be a very dangerous man. Two of the men grasped the doctor and led him along toward the entrance to the laboratory cave which stood wide open in the gathering daylight. Frink paused long enough to shut the side of the hill and conceal the ship, and then followed the doctor. In the cave the door was shut and the doctor placed against the wall under the window through which he had peered earlier in the night. Slavatsky took his seat at the table, his malignant black eyes boring into the Doctor. Carson and Willis sat on the edge of the operating table, evidently still partially under the effects of the anesthetic that had been administered to them.
"How did you get back here?" demanded Slavatsky.
"Find out!" snapped Dr. Bird.
The dwarf rose threateningly.
"Speak respectfully to me; I am the Master of the World!" he roared in an angry voice. "Answer my questions when I speak, or means will be found to make you answer. How did you get back here?"
Dr. Bird maintained a stubborn silence, his fierce eyes answering the dwarf's, look for look, and his prominent chin jutting out a little more squarely. Carson suddenly broke the silence.
"That's not the Bird we had here earlier," he cried as he staggered to his feet.
"What do you mean?" demanded Slavatsky whirling on him.
"Look at his hands!" replied Carson pointing.
Slavatsky looked at Dr. Bird's long mobile fingers and an evil leer came over his countenance.
"So, Dr. Bird," he said slowly, "you thought to match wits with Ivan Slavatsky, the greatest mind of all the ages. For a time you fooled me when your double was operated on here, but not for long. I presume you thought that we had no way of detecting the substitution? You have discovered differently. Where is your friend, Mr. Carnes?"
"Didn't your men leave him in the cabin when you kidnapped me?"
Slavatsky looked at Frink inquiringly.
"He stayed in the cabin if he was in it when we got there," the leader of the kidnapping gang replied. "He got a full shot of lethane and he's due to be asleep yet. I don't know how this man recovered. I left him there myself."
"Fool!" shrieked Slavatsky. "You brought me a double, a dummy whom I wasted my time in operating on. Was the other a dummy, too?"
"I didn't enter the cabin."
Slavatsky shrugged his shoulders.
"If that is all the good the menthium I have injected has done you, I might as well have saved it. It doesn't matter, however: we have the one we wanted. Dr. Bird, it was very thoughtful of you to come here and offer your marvelous brain to strengthen mine. I have no doubt that you will yield even more menthium than Professor Williams did this evening especially as I will extract your entire supply and reduce you to permanent idiocy. I will have no mercy on you as I have on the others I have operated on."
Dr. Bird blanched in spite of himself at the ominous words.
"You have the whip-hand for the moment, Slavatsky, but my time may come – and if it does, I will remember your kindness. I saw your operation on Professor Williams this evening and know your power. I also know that you stole the idea and the method from Sweigert of Vienna. I saw you inject the fluid you drew into Willis' brain. Shall I tell what else I saw?"
It was the dwarf's turn to blanch, but he recovered himself quickly.
"Into the chair with him!" he roared.
Three of the men grasped the doctor and forced him into the chair and Slavatsky started the generator. The violet light bathed Dr. Bird's head and he felt a stiffness and contraction of his neck muscles, and as he tried to shout out his knowledge of Slavatsky's treachery, he found that his vocal chords were paralyzed. Through a gathering haze he could see Carson approaching with an anesthesia cone and the sweet smell of lethane assailed his nostrils. He fought with all his force, but strong hands held him, and he felt himself slipping – slipping – slipping –