"What on earth were they doing?" asked Carnes in a whisper.
"That was Professor Williams of Yale. They were depriving him of his memory. There will be another amnesia case in the papers to-morrow. I haven't time to explain their methods now: we've got to act. You have a flash-light?"
"Yes, and my gun. Shall we break in? There are only three of them, and I think we could handle the lot."
"Yes, but the others may return at any time and we want to bag the whole lot. They've done their damage for to-night. You heard my orders to Lieutenant Maynard, didn't you?"
"Yes."
"He should be somewhere in these hills to the south with assistance of some sort. The signal to them is three long flashes followed in turn by three short ones and three more long. Go and find them and bring them here. When you get close give me the same light signal and don't try to break in unless I am with you. I am going to reconnoitre a little more and make sure that there is no back entrance through which they can escape. Good luck. Carnes: hurry all you can. There is no time to be lost."
______________________________The secret service operative stole away into the night and Dr. Bird climbed back down the rope and took his place at the window. Willis lay on the operating table unconscious, while Slavatsky and Carson studied the now partially emptied syringe.
"You gave him his full share all right," Carson was saying. "I guess you are playing square with us. I'll take mine now."
He lay down on the operating table and the dwarf fitted an anesthesia cone over his face and opened the valve of the gas cylinder. In a moment he closed it and rolled the unconscious man on his face and deftly inserted the long needle. Instead of injecting a portion of the contents of the syringe as Dr. Bird had expected to do, he drew back on the plunger for a minute and then took out the needle and held the syringe to the light.
"Well, Mr. Carson," he said with a malignant glance at the unconscious figure, "that recovers the dose you got a couple of weeks ago while Willis watched me. I don't think you really need any menthium; your brain is too active to suit me as it is."
He gave an evil chuckle and walked to the far side of the cave and opened a secret panel. He drew from a recess a flask and carefully emptied a portion of the contents of the syringe into it. He replaced the flask and closed the panel, and with another chuckle he limped over to a chair and threw himself down in it. For an hour he sat motionless and Dr. Bird carefully worked his way back along the branch and climbed the rope and started for the hollow.
______________________________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 and then falling into an immense void. His head slumped forward on his chest and Slavatsky shut off the generator.
"On the table," he said briefly.
Four men picked up the herculean frame of the unconscious doctor and hoisted him up on the table. Carson seized his head and bent it forward and the dwarf took from a case a syringe with a five-inch needle. He touched the point of it to the base of the doctor's brain.
"Slavatsky! Look!" cried Frink.
With an exclamation of impatience the dwarf turned and stared at a disc set on the wall of the cave. It was glowing brightly. With an oath he dropped the syringe and snapped a switch, plunging the cave into darkness. A tiny panel in the door opened to his touch and he stared out into the light.
"Soldiers!" he gasped. "Quick, the back way!"
As he spoke there came a sound as of a heavy body falling at the back of the cave. Slavatsky turned the switch and flooded the cave with light. At the back of the cave stood Operative Carnes, an automatic pistol in his hand.
"Open the main door!" Carnes snapped.
______________________________Slavatsky made a move toward the light, and Carnes' gun roared deafeningly in the confined space. The heavy bullet smashed into the wall an inch from the dwarf's hand and he started back.
"Open the main door!" ordered Carnes again.
The men stared at one another for a moment and the dwarf's eyes fell.
"Open the door, Frink," he said.
Frink moved over to a lever. He glanced at Slavatsky and a momentary gleam of intelligence passed between them. Frink raised his hand toward the lever and Carnes gun roared again and Frink's arm fell limp from a smashed shoulder.
"Slavatsky," said Carnes sternly, "come here!"
Slowly the dwarf approached.
"Turn around!" said Carnes.
He turned and felt the cold muzzle of Carnes' gun against the back of his neck.
"Now tell one of your men to open the door," said the detective. "If he promptly obeys your order, you are safe. If he doesn't, you die."
Slavatsky hesitated for a moment, but the cold muzzle of the automatic bored into the back of his neck and when he spoke it was in a quavering whine.
"Open the door, Carson," he whimpered.
There was moment of pause.
"If that door isn't open by the time I count three," said Carnes, " as far as Slavatsky is concerned, it's just too bad. I'll have four shots left and I'm a dead shot at this range. One! Two!"
His lips framed the word "three" and his fingers were tightening on the trigger when Carson jumped forward with an oath. He pulled a lever on the wall and the door swung open. Carnes shouted and through the opened door came a half dozen marines followed by an officer.
"Tie these men up!" snapped Carnes.
______________________________In a trice the six men were securely bound and Frink's bleeding shoulder was being skilfully treated by two of the marines. Carnes turned his attention to the unconscious doctor.
He rolled him over on his back and began to chafe his hands. An officer in a naval uniform came through the door and with a swift glance around, bent over Dr. Bird. He raised one of the doctor's eyelids and peered closely at his eye and then sniffed at his breath.
"It's some anesthetic I don't know," he said. "I'll try a stimulant."
He reached in his pocket for a hypodermic, but Carnes interrupted him.
"Earlier in the evening Dr. Bird said they were using lethane," he said.
"Oh, that new gas the Chemical Warfare Service has discovered," said the surgeon. "In that case I guess it'll just have to wear off. I know of nothing that will neutralize it."
Without replying, Carnes began to feverishly search the pockets of the unconscious scientist. With an exclamation of triumph he drew out a bottle and uncorked it. A strong smell as of garlic penetrated the room and he held the opened bottle under Dr. Bird's nose. The doctor lay for a moment without movement, and then he coughed and sat up half strangled with tears running down his face.
"Take that confounded bottle away, Carnes!" he said. "Do you want to strangle me?"
He sat up and looked around.
"What happened?" he demanded. "Oh, yes, I remember now. That brute was about to operate on me. How did you get here?"
"Never mind that, Doctor. Are you all right?"
"Right as a trivet, old dear. How did you get here so opportunely?"
"I was a little slow in locating Lieutenant Maynard and the marines. When we got here I was afraid that we couldn't find the door, so I took Maynard and a detail around to the back and I went up to the top and slid down our cord and looked in the window. You were unconscious and Slavatsky was bending over you with a needle in his hand. I was about to try a shot at him when something called their attention to the men in front and I squeezed through the window and dropped in on them. They didn't seem any too glad to see me, but I overlooked that and insisted on inviting the rest of my friends in to share in the party. That's all."