"All right," he said shortly and limped to a cabinet on the wall. He drew a key from his pocket and opened it and pulled out a leather-bound book. "Look all you please. I was supposed to get the most. It was my idea."

"You were to get one share and a half, while Willis, Frink and I got one share each and the rest half a share," said Carson. "I know how much has been given and it won't take me but a minute to check up."

He bent over the book, but Willis interrupted.

"Better put it away, Carson," he said, "here come the rest and we don't want them to know we suspect anything."

He pointed toward a disc on the wall which had begun to glow.

Slavatsky looked at it and grasped the book from Carson and replaced it in the cabinet. He moved over and started the generator and the tube began to glow with a violet light. A noise came from the outside and the door opened. Four men entered carrying a fifth whom they propped up in the chair under the glowing tube.

"Did everything go all right?" asked the dwarf eagerly.

"Smooth as silk," replied one of the four. "I hope we get some results this time."

The dwarf bent over the ray apparatus and made some adjustments and the head of the unconscious man was bathed with a violet glow. For three minutes the flood of light poured on his head and then the dwarf shut off the light and Carson and Willis lifted the figure and laid it on the operating table. The dwarf bent over the man and inserted the needle of a hypodermic syringe into the back of the neck at the base of the brain. The needle was an extremely long one, and Dr. Bird gasped as he saw four inches of shining steel buried in the brain of the unconscious man.

Slowly Slavatsky drew back the plunger of the syringe and Dr. Bird could see it was being filled with an amber fluid. For two minutes the slow work continued, until a speck of red appeared in the gla.s.s syringe barrel.

"Seven and a half cubic centimeters!" cried the dwarf in a tone of delight.

"Fine!" cried Carson. "That's a record, isn't it?"

"No, we got eight once. Now hold him carefully while I return some of it."

Slavatsky slowly pressed home the plunger and a portion of the amber fluid was returned to the patient's skull. Presently he withdrew the needle and straightened up and held it toward the light.

"Six centimeters net," he announced. "Take him back, Frink. I'll give Carson and Willis their share now and we'll take care of the rest of you when you return. Is the ship well stocked?"

"Enough for two or three more trips."

"In that case, I'll inject this whole lot. Better get going, Frink, it's pretty late."

The four men who had brought the patient in stepped forward and lifted him from the table and bore him out. Dr. Bird dropped the canvas screen and strained his ears. A faint whir told him that the globe had taken to the air. He slid back along the limb of the tree until he touched the rope and silently climbed hand over hand until he gained the crest. He bent his back to the task of raising Carnes, and the operative soon stood beside him on the ledge surmounting the cliff.

"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 a.s.sistance 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.

A faint 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 b.u.t.ton 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.