By Capt. S. P. Meek

“Is the maneuver progressing as you wish. Dr. Bird?” asked the Chief of the Air Corps.

The famous scientist lowered his binoculars and smiled.

“Exactly, General,” he replied. “They are keeping a splendid line.”

“It is the greatest concentration of air force that this country has ever seen,” said General Merton proudly.

With a nod, Dr. Bird raised his glasses to his eyes and resumed his steady gaze. Five thousand feet below and two miles ahead of the huge transport plane which flew the flag of the Chief of the Air Corps, a long line of airplanes stretched away to the north and to the south. Six hundred and seventy-two planes, the entire First Air Division of the United States Army, were deployed in line at hundred-yard intervals, covering a front of nearly forty miles. Fifteen hundred feet above the ground, the line roared steadily westward over Maryland at ninety miles an hour. At ten-second intervals, a puff of black dust came from a discharge tube mounted on the rear of each plane. The dust was whirled about for a moment by the exhaust, and then spread out in a thin layer, marking the path of the fleet.

“I hope the observers on the planes are keeping careful notes of the behavior of those dust clouds,” said Dr. Bird after an interval of silence. “We are crossing the Chesapeake now, and things may start to happen at any moment.”

“They’re all on their toes, Doctor,” replied General Merton. “I understood in a general way from the President that we are gathering some important meteorological data for you, but I am ignorant of just what this data is. Is it a secret?”

Dr. Bird hesitated.

“Yes,” he said slowly, “it is. However, I can see no reason why this secret should not be entrusted to you. We are seeking a means of ending the great drought which has ravaged the United States for the past two years.”

Before General Merton had time to make a reply, his executive officer hastened forward from the radio set which was in constant communication with the units of the fleet.

“Two of the planes on the north end of the line are reporting engine trouble, sir,” he said.

Dr. Bird dropped his glasses and sat bolt upright.

“What kind of engine trouble?” he demanded sharply.

“Their motors are slowing down for no explainable reason. I can’t understand it.”

“Are their motors made with sheet steel cylinders or with duralumin engine blocks?”

“Sheet steel.”

“The devil! I hadn’t foreseen this, although it was bound to happen if my theory was right. Tell them to climb! Climb all they know! Don’t let them shut off their motors for any reason, unless they are about to crash. Turn this ship to the north and have the pilot climb fast!”

A nod from General Merton confirmed the doctor’s orders. The line of planes kept on to the west, but the flagplane turned to the north and climbed at a sharp angle, her three motors roaring at full speed. With the aid of binoculars, the two ships in trouble could be picked out, falling gradually behind the line. They were flying so slowly that it seemed inevitable that they would lose flying speed and crash to the ground.

“More speed!” cried the doctor. “We’ve elevation enough!”

The altimeter stood at eight thousand feet when the pilot leveled out the flagplane and tore at full speed toward the laboring ships. The main fleet was twenty miles to the west.

They were almost above the point where the two planes had first began to slow down. As they winged along, the three motors of the flagplane took on a different note. It was a laboring note, pitched on a lower scale. Gradually the air-speed meter of the ship began to show a lower reading.

“Locate us on the map, Carnes!” snapped Dr. Bird.

Operative Carnes of the United States Secret Service bent over a large-scale map of Maryland, spread open on a table. With the aid of the navigating officer, he spotted on the map the point over which the plane was flying.

“There goes Burleigh’s ship!” cried the executive officer.

There was a gasp from the occupants of the flagplane’s cabin. Far below them, one of the crippled planes had slowed down until it had lost flying speed. Whirling like a leaf, it plunged toward the ground. Two small specks detached themselves from the falling mass. They hovered over the falling plane for an instant. Suddenly a patch of white appeared in the air, and then another. The two specks fell more slowly.

“Good work!” exclaimed General Merton. “They took to their ’chutes just in time.”

“We’ll be taking them in a few minutes if our motors don’t pick up!” replied the executive officer.

Far below them, the doomed plane crashed to the ground. As it struck there was a blinding flash followed by vivid flames as the gasoline from the bursted tank ignited. The two members of the crew were drifting to the east as they fell. It was evident that they were in no danger.

“Where is Lightwood’s plane?” asked General Merton anxiously.

“It’s still aloft and making its way slowly north. He intends to try for an emergency landing at the Aberdeen Proving Ground field,” replied the executive officer.

“That’s where we had better head for,” said Dr. Bird. “I hope that the charge on Captain Lightwood’s plane discharges through the tail skid when he lands. If it doesn’t, he’ll be in serious danger. Follow him and we’ll watch.”

Five thousand feet below them, the crippled plane limped slowly along toward Aberdeen. It was gradually losing elevation. Two specks suddenly appeared in the air, followed by white patches as the parachutes opened. Captain Lightwood and his gunner had given up the unequal fight and taken to the air. As the ship struck the ground, again there was a blinding flash, followed by an inferno of roaring flames.

“We’re not in much better shape than they were, General,” said the executive officer as he came back from the control room where the pilots were heroically striving to keep their motors turning over fast enough to keep up flying speed. “We’d better get into our ’chutes.”

“The Proving Ground is just ahead,” said the doctor. “Can’t we make it by sacrificing our elevation?”

“We’re trying to do that, Doctor, but we’re down to four thousand now and falling fast. Get ready to jump.”

Dr. Bird buckled on the harness of the pack parachute which the executive officer offered him. The rest of the crew had hurriedly donned their packs and stood ready.

For another five minutes the plane struggled on. Suddenly a large flat expanse of open ground which had been in sight for some time, seemed to approach with uncanny rapidity.

“There’s the landing field!” cried the General. “We’ll make it yet!”

Lower and lower the plane sank with the landing field still too far away for comfort. The pilot leveled off as much as he dared and drove on. The motors were laboring and barely turning over at idling speed. They passed the nearer edge of the field with the flagplane barely thirty feet off the ground. In another moment the wheels touched and the plane rolled to a halt.

“Don’t get out!” cried Dr. Bird.

He looked around the cabin and picked up a coil of bare antenna wire which hung near the radio set. He wrapped one end of the wire around the frame of the plane. To the other end, he attached his pack ’chute.

“Open the door!” he cried.

As the door swung open, he threw the ’chute out toward the ground. As it touched, there was a blinding flash, followed by a report which shook the plane. A strong odor of garlic permeated the air.

“All right!” cried the doctor cheerfully. “All out for Aberdeen. The danger is past.”

He set the example by jumping lightly from the plane. General Merton followed more slowly, his face white and his hands shaking.

“What was it, Doctor,” he asked. “I have been flying since 1912, yet I have never seen or heard of anything like that.”

“Just a heavy charge of static electricity,” replied the doctor. “That was what magnetized your cylinder walls and your piston rings and slowed your motors down. It was the same thing that wrecked those two ships. Unless it leaks off, the men of some of your other ships are due to get a nasty shock when they land to-night. I discharged the charge we had collected through a ground wire. Here comes a car, we’ll go up to Colonel Wesley’s office. Carnes, you have these maps?”

“Surely, Doctor.”

“All right, let’s go.”

“But what about this ship, Doctor?” objected the General. “Can’t something be done about it?”

“Certainly. I hadn’t forgotten it. Have your crew stand by. I’ll telephone Washington and have some men with apparatus sent right down from the Bureau of Standards. They’ll have it ready for flying in the morning. We’ll also have search parties sent out in cars to locate the crews of those abandoned ships and bring them in. Now let’s go.”

Colonel Wesley, the commanding officer of the Aberdeen Proving Ground, welcomed Carnes and Dr. Bird warmly.

“I’ll tell you, General Merton,” he said to the Chief of the Air Corps, “if you ever get up against something that is beyond all explanation, you want to get these two men working on it. They are the ones who settled that poisoning case here, you know.”

“Yes, I read of that,” replied the general. “I am inclined to think that they are up against something even queerer right now.”

Colonel Wesley’s eyes sparkled.

“Give your orders, Dr. Bird!” he cried. “Since our last experience with you, you can’t give an order on this post that won’t be obeyed!”

“Thank you, Colonel,” said Dr. Bird warmly. “One reason why I came here was that I knew that I could count on your hearty cooperation. The first thing I want is two cars. I want them sent out to bring in the crews of two ships which were abandoned some eight miles south of here. Carnes will locate them on the map for your drivers.”

“They’ll be ready to start in five minutes, Doctor. What next?”

“Turn out every man and every piece of transportation you have to-morrow morning. I want the men armed. They will have to search a stretch of swamp south of here, inch by inch, until they find what I’m looking for.”

“They’ll be ready, Doctor. Would it be indiscreet for me to ask what it’s all about?”

“Not at all, Colonel. I was about to explain to General Merton when trouble started. I am searching for the cause of the great drought which has been afflicting this country for the past two years. If I can find the cause, I hope to end it.”

“Oh! I had a sneaking hope that we were in for another skirmish with that Russian chap, Saranoff, whose men started that poison here.”

“I rather think we are, Colonel Wesley.”

General Merton laughed.

“I’ll swallow a good deal, Dr. Bird,” he said, “but when you talk of an individual being responsible for the great drought, it’s a little too much. A man can’t control the weather, you know!”

“Yet a man, or an incarnate devil I don’t know which he is did control the weather once, as well as the sun. But for the humble efforts of two Americans, aided by a Russian girl whose brother Saranoff had murdered, he might be still controlling it.”

General Merton was silent now.

“Carnes, let me have that map,” went on the doctor. When the detective had unrolled a map of the United States on Colonel Wesley’s table, Dr. Bird continued, pointing to the map as he spoke.

“On this map,” he said, “is plotted the deficiency in rainfall for the past year, from every reporting station in the United States. These red lines divide the country into areas of equal deficiency. The area most affected, as you can see, is longer east and west, than it is north and south. It is worst in the east, in fact in this very neighborhood. Even a casual glance at the map will show you that the center of the drought area, from an intensity standpoint, lies in Maryland, a few miles south of here.”

“In fact, just about where those two planes went down,” added Carnes.

“Precisely, old dear. That was why we went over that section with the fleet. Now, gentlemen, note a few other things about this drought. The areas of drought follow roughly the great waterways, the Ohio and the Potomac valleys being especially affected. In other words, the drought follows the normal air currents from this point. If something were to be added to the air which would tend to prevent rain, it would in time drift, just as the drought areas have drifted.”

General Merton and Colonel Wesley bent over the map.

“I believe you’re right, Doctor,” admitted the general.

“Thank you. The President was convinced that I was before he placed the First Air Division under my orders. Frankly, that search was the real object of assembling the fleet. The maneuvers are a mere blind.”

General Merton colored slightly.

“Now, I’ll try to give you some idea of what I think is the method being used,” went on the doctor, ignoring General Merton’s rising color. “In the past, rain has been produced in several cases where conditions were right that is, when the air held plenty of moisture which refused to fall by the discharge from a plane of a cloud of positively charged dust particles. Ergo, a heavy negative charge in the air, which will absorb rather than discharge a positive charge, should tend to prevent rain from falling. I believe that a stream of negative particles is being liberated into the air near here, and allowed to drift where it will. That was my theory when I had the First Air Division equipped with those dust ejector tubes.

“I knew that if such a condition existed, the positively charged dust would be pulled down toward the source of the negative particle stream, which must, in many ways, resemble a cathode ray. That was why I wanted the behavior of the dust clouds watched and reported. What I did not foresee was that the iron and steel parts of the plane, accumulating a heavy negative charge, would be magnetized enough to slow down the motors and eventually wreck the ships.”

“We have had eight ships wrecked unexplainably within twenty miles of here, all of them to the south, during the past year,” said Colonel Wesley.

“It had slipped my notice. At any rate, the behavior of the ships this afternoon showed me that my theory is correct, and that some such device exists and is in active operation. Our next task is to locate it and destroy it.”

“You shall have every man on the Proving Ground!” cried Colonel Wesley.

“Thank you. General Merton, will you detach three ships from the First Air Division by radio and have them report here? I want two pursuit ships and one bomber, with a rack of hundred-pound demolition bombs. All three must have duralumin cylinder blocks.”

“I’ll do it at once, Doctor,” the general agreed.

“Thank you. Carnes, telephone Washington for me. Tell Dr. Burgess that I want Tracy, Fellows and Von Amburgh, with three more men down here by the next train. Also tell him to have Davis rig up a demagnetizer large enough to demagnetize the motors of a transport plane and bring it down here to fix up General Merton’s ship. When you have finished that, get hold of Bolton and ask for a dozen secret service men. I want selected men with Haggerty in charge.”

“All right, Doctor. Shall I tell Miss Andrews to come down as well?”

Dr. Bird frowned.

“Certainly not. Why would she come down here?”

“I thought she might be useful, Doctor.”

“Carnes, as you know, I dislike using women because they can’t control their emotions or their expressions. She would just be in the way.”

“It seems to me that she saved both our lives in Russia, Doctor, and but for her, you wouldn’t have come out so well in your last adventure on the Aberdeen marshes.”

“She did the first through uncontrolled emotions, and the second through a flagrant disobedience of my orders. No, don’t tell her to come. Tell her not to come if she asks.”

Carnes turned away, but hesitated.

“Doctor, I wish you’d let me have her come down here. I didn’t trust her at first when you did, but she has proved her loyalty and worth. Besides, I don’t like the idea of leaving her unguarded in Washington with you and me down here, and with Haggerty coming down.”

Dr. Bird looked thoughtful.

“There’s something in that, Carnes,” he reflected. “All right, tell her to come along, but remember, she is not in on this case. She is being brought here merely for safety, not to mix up in our work.”

“Thanks, Doctor.”

The detective returned in ten minutes with a worried expression.

“She wasn’t in your office, Doctor,” he reported.

“Who? Oh, Thelma. Where was she?”

“No one seems to know. She left yesterday afternoon and hasn’t returned.”

“Oh, well, since I am out of the city, I expect she decided to take a vacation. Women are always undependable. Did you get hold of the rest?”

“They’ll be down at midnight, all but Davis. He’ll come down in the morning.”

“Good enough! Now, Colonel, if you’ll have the officers who are going out to-morrow assembled, we’ll divide the territory and make our plans for the search.”

A week later, the situation was unchanged. Secret service operatives and soldiers from the Proving Ground had covered, foot by foot, square miles of territory south of the Proving Ground, but without result. Not a single unexplainable thing had been found. Sensitive instruments sent down from the Bureau of Standards, instruments so sensitive that they would detect an electric light burning a mile away, had yielded no results. As a final measure, General Merton had ordered a dozen planes with steel-cylindered motors to the Proving Ground and they had repeatedly crisscrossed the suspected territory, but had acquired no static charge large enough to affect them. It was evident that Saranoff’s device, if it existed, had been moved, or else was not in operation.

Also, to Carnes’ openly expressed and Dr. Bird’s secret worry, Thelma Andrews had not returned to the Bureau of Standards. The Russian girl, formerly known as Feodrovna Androvitch, a tool and follower of Ivan Saranoff, had acted with Carnes and the doctor in their long drawn-out fight with the arch-communist often enough to be a marked woman.

Urged by Carnes, Bolton, the head of the Secret Service, put a dozen of his best men on her trail, but they found nothing. She had disappeared as thoroughly as if the earth had opened and swallowed her up. At last, as the combing of the Aberdeen marshes yielded no results, Dr. Bird acceded to Carnes’ request, and the detective left for Washington to take personal charge of the search. Dr. Bird sat alone in his quarters at the Officers’ Club, futilely wracking his brains for a clue to his further procedure.

The telephone rang loudly. With a grunt, he took down the receiver.

A feminine voice spoke with a strong foreign accent.

“I vant der Herr Doktor Vogel, plees!”

“You want who? Oh, yes. Vogel bird! This is Dr. Bird speaking.”

The voice instantly lost both its foreign accent and its guttural quality.

“I thought so when you spoke, Doctor, but I wanted to make sure. This is Thelma Andrews.”

“Where the devil have you been? Half the Secret Service is looking for you, including Carnes, who deserted me and is in Washington.”

“He is? I’m sorry. Listen, Doctor, it’s a long story and I can’t go into details now. I got a clue on the day you left. As I couldn’t get in touch with you, I followed it myself. I’ve located Saranoff’s main base in the Bush River marshes.”

“You have! Where is it?”

“It’s underground and you’ve passed over it a dozen times during the past week. It’s unoccupied now and the machines are idle until your search is over. I know the way to it. If you’ll join me now, we can get in and hopelessly wreck the device in a short time. To-morrow you can bring your men down here and take charge of it.”

Dr. Bird’s eyes glistened.

“I’ll come at once, Thelma!” he cried. “Where are you?”

“I’m down on Romney Creek. Come down to the Water Impact Range below Michaelville, and I’ll meet you at the wharf. You’d better come alone, because we’ll have to sneak.”

“Good for you!” cried the doctor. “I’ll be down in an hour.”

“All right, Doctor. I’ll be waiting for you.”

At Michaelville, Dr. Bird left his car and stepped on the scooter which ran on the narrow gauge track connecting the range house with the wharf on Romney Creek. He started it with no difficulty and it coughed away into the night. For three and a half miles, nothing broke the monotony of the trip. Dr. Bird, his hand on the throttle, kept his eyes on the twin ribbons of steel which slid along under the headlight. The road made a sharp turn and emerged from the thick wood through which it had been traveling. Hardly had the lights shot along the track in the new direction than Dr. Bird closed the throttle and applied the brakes rapidly. A heavy barricade of logs was piled across the track.

The doctor pressed home on the brake lever until the steel shoes screamed in protest, but no brakes could bring the heavy scooter to a stop as swiftly as was needful to avoid a crash. It was still traveling at a good rate of speed when it rammed into the barricade and overturned.

Dr. Bird was thrown clear of the wrecked scooter. He landed on soft mud beside the track. As he strove to rise, the beam of a flashlight struck him in the eyes and a guttural, sneering voice spoke through the darkness.

“Don’t move, Dr. Bird. It will be useless and will only lead to your early death, a thing I should regret.”

“Saranoff!” cried Dr. Bird.

“I am flattered, Doctor, that you know my voice. Yes, it is I, Ivan Saranoff, the man whom you have so often foiled. You drove me from America and tried to bar the road against my return, but I only laughed at your efforts. I returned here only for one purpose, to capture you and to compass your death.”

Dr. Bird rose to his feet and laughed lightly.

“You’ve got me, Saranoff,” he said, “but the game isn’t played out yet. I represent an organization which won’t end with my death, you know.”

A series of expletives in guttural Russian answered him. In response to a command from their leader, two men came forward and searched the doctor quickly and expertly, removing the automatic pistol which he carried under his left armpit.

“As for your organization, as you call it pouf!” said the Russian scornfully. “Carnes, a brainless fool who does only as you tell him, a few half-wits in the Bureau of Standards, some of them already in my pay, and one renegade girl. She shall learn what it means to betray the Soviets and their leader.”

“You’ll have to catch her first,” replied Dr. Bird, a sardonic grin on his face.

“I have but to snap my fingers and she will come whining back, licking my hand and imploring mercy,” boasted the Russian. “Bring him along!”

Two men approached and Seized the doctor by his arms. Dr. Bird shook them off contemptuously.

“Keep your filthy paws off me!” he cried. “I know when I’m bested, and I’ll come quietly, but I won’t be dragged.”

The men looked at their leader for orders. From behind his light, the Russian studied his opponent. He gave vent to a stream of guttural Russian. The men fell back.

“For your information, Doctor,” he said in a sneering tone. “I have told my men to follow you closely, gun in hand. At the slightest sign of hesitation, or at the first attempt to escape, they will fire. They are excellent shots.”

“Lead on, Saranoff,” was Dr. Bird’s cheery comment.

With a shrug of his shoulders, the leader of the Young Labor party turned and made his way along the track toward the wharf. Dr. Bird looked anxiously ahead as they approached, fearing that Feodrovna Androvitch would be discerned in her hiding place. Saranoff correctly interpreted his gaze.

“Does der Herr Doktor Vogel eggspect somevun?” he asked in the voice which had first come over Dr. Bird’s telephone. The doctor started and the Russian went on in the voice of the doctor’s secretary. “I’m so glad you came, Dr. Bird. I am going to take you directly to the main base of our dearly beloved friend, Ivan Saranoff.”

An expression that was a mixture of chagrin and relief spread over Dr. Bird’s face.

“Sold, by thunder!” he cried.

The Russian laughed sardonically and tramped on in silence. Tied to the Romney Creek wharf was a boat with powerful electric motors, driven by storage batteries. At a nudge from his captors, Dr. Bird took his place in the craft. It glided silently away down the creek toward the Chesapeake’s mouth.

In the bay, the boat veered to the south and ran along the shore until the mouth of Bush River opened before them. It turned west up the river, coming to a halt at one of the occasional bits of high ground which bordered the river.

“We get off here, Doctor,” said Saranoff. “My base, which you have wasted so much time seeking, lies within a hundred yards of this point. Before I take you there, you may be interested in watching us conceal our boat.”

Before the doctor’s surprised gaze, the edges of a huge box rose above the surface of the water, around the electric boat. The boat was raised and water could be heard running out of the box which held it. When the box was drained, a man leaped in and made some adjustments. A cover, hinged on one side, swung over and closed the box tightly with the boat inside. Men closed clamps which held it in position. As they sprang to shore, the box sunk silently out of sight below the surface of the water.

“It is now beneath a foot of mud, Doctor,” laughed the Russian, “and there is nothing to lead a searching party to suspect its existence. Now I will take you to my base.”

He led the way for a hundred yards over the ground. Before them loomed an old abandoned fisherman’s shack. They entered to find merely a barren room. The Russian stepped to the far side and manipulated a hidden lever. Half of the floor slid to one side, disclosing a flight of steps leading down into Stygian darkness.

Flashlight in hand, Saranoff descended, Dr. Bird following closely on his heels. They went down twenty-one steps before the stairs came to an end. Above them, the floor could be heard closing. There was a sharp click and the cavern was flooded with light.

Dr. Bird looked around him with keen interest. Before him stood a static generator of gigantic proportions and of a totally unfamiliar design. Attached to it was an elliptic reflector of silvery metal, from which rose a short, stubby projector tube.

“I suppose, Dr. Saranoff ” began Dr. Bird.

“Ivan Saranoff, if you please, Doctor,” interrupted the Russian. “I have renounced the trumpery distinctions of your bourgeois civilization as far as I am concerned.”

“I suppose, Ivan Saranoff,” said Dr. Bird obligingly, “that this is the apparatus with which you send out a stream of negative particles.”

“It is, Doctor. I had no idea that the nature of it would ever be discovered; at least not until I had changed the United States to a second Sahara desert. I reckoned without you. In point of fact, at the time that I built this device and started it in operation, I had not clashed with you. Now, I know that my plan is a failure. You have left data on which other men can work, have you not?”

“Surely.”

“I would not have believed you had you said otherwise,” replied the Russian with a sigh. “Yet this device has done much good. Now it shall be destroyed. It has not been a failure, for its destruction will accomplish both yours and that of your friend, Carnes.”

“You haven’t caught Carnes yet.”

“That is easy. The same bait which caught you has caught him even more easily. I have a real sense of humor, Doctor, and before I went out of my way to bring you here, my plans were carefully laid. Mr. Carnes is now on his way here from Washington, lured by my voice. He is rushing, he thinks, to your rescue.”

“What ”

Dr. Bird was suddenly silent.

“I am glad you comprehend my plan so readily, Doctor. Yes, indeed, Mr. Carnes knows that I have captured you. He knows the exact location of this cavern and, more important, he knows the location of the power line which feeds my device when it is in operation. He also knows that there is stored in this cavern, fifty pounds of radite, your ultra-explosive. He knows that you are chained close to the explosive and that it is rigged with a detonator, connected with the power line. In only one thing is he in error.

“He thinks, that if he can sever the power line before he attempts to penetrate the cavern, that the charge will be rendered harmless, and that you will be safe. In point of fact, the charge is set with an interrupter detonator which will explode as soon at the power line is severed. It pleases my sense of humor that it will be the hand of your faithful friend, Carnes, that will send you in fragments to eternity.”

Beads of sweat shone on Dr. Bird’s head as the Russian finished his speech, but his expression of amused interest did not change. Neither did his voice, when he spoke, betray any nervousness.

“And I presume that Carnes is also to be blown into bits by the explosion?” he asked.

“No, indeed, Doctor, that would frustrate one of the most humorous angles of the whole affair. He will cut the line at the base of a large rock, some two hundred yards from here, far enough away that he will not be seriously injured by the force of the explosion. Thus he will witness the explosion and realize what he has done. In order to be sure that he knows, as soon as he cuts the wire, my men will capture him. I, personally, will tell him of it. I wish to see his face when he realizes what he has unwittingly done.”

“Then, I presume, you’ll kill him?”

“I doubt it. I rather think I’ll let him live. He should be useful to me.”

“Carnes will never work for you!”

“With Feodrovna in my power, I rather think that Mr. Carnes will be an efficient and loyal servant. If not, he shall have the pleasure of watching me wreak my vengeance on her before he, himself, takes his last long trip.”

“Saranoff,” said Dr. Bird in a level voice, his piercing eyes boring straight into the Russian’s, “I will remember this. Later, when you grovel at my feet and beg for mercy, it will be my friend, Operative Carnes, who will read your doom to you and choose the manner of it. I can promise you that your death will not be an easy one.”

The Russian laughed, albeit the laugh had more of uneasiness than humor in it.

“When you have me in your power, Doctor, you may do as you like,” he said, “but I do not fear dead men. In another two hours, you will be among the dead.”

He turned to the three Russians who stood behind him.

“Seize him!” he cried.

The Russians leaped forward, but Dr. Bird was not caught napping. The first one went down like a felled tree before the doctor’s fist. The other two came in cautiously. Dr. Bird sprang forward, feinting. As he leaped back, his foot struck a rod which Ivan Saranoff had thrust behind him. He staggered and fell. Before he could recover his balance, the two burly Russians were on him.

Even then, they had no easy task. Dr. Bird weighed over two hundred and there was not an ounce of fat or surplus flesh on him. First one, and then the other, of the Russians was thrown off him, but they returned to the attack, unsubdued by the crashing blows which the doctor landed on their faces and heads.

Gradually their ardor began to evaporate. With a sudden effort, Dr. Bird strove to regain his feet. A crash as of all the thunders of the universe sounded in his ears, and flashes of vivid light played before his eyes. He felt himself falling down ... down....

He recovered consciousness to find his feet shackled and fastened to rings set in the concrete of the cavern wall. His head throbbed horribly. He raised his hands and found a huge bump on his head, from which thickened blood trickled sluggishly down his cheek. The cavern was flooded with light. On the wall before him, a clock told off the seconds with a metallic tick. He bent down and examined his shackles.

“I’m afraid you can’t unfasten them, Doctor,” said a sardonic voice.

He looked up to see Saranoff.

“I’m sorry I had to hit you so hard,” went on the Russian. “Your half hour of unconsciousness has lessened by that much the time which is yours to indulge in an agony of apprehension. Look.”

Dr. Bird’s gaze followed the Russian’s finger. On the floor, twenty feet from where he was shackled, stood a yellow can with the mark of the Bureau of Standards on its side. He recognized it at once as a radite container, a can of the terrible ultra-explosive which he himself had perfected. He shuddered at the thought of the havoc which its detonation would cause.

“Yes, Doctor, that is a can of radite,” said the Russian. “Allow me also to call your attention to the interrupter fuse which is attached to it. When Mr. Carnes cuts the wire outside, you know well enough what will happen. Now, let me invite your attention to the clock on the wall before you. Mr. Carnes arrived at the Bush River station of the P. B. and W. at 2:15 A.M. He had a little trouble getting a boat, but he is now on his way here. It is 2:25. I think he will arrive between 3:30 and 4:00. Perhaps five minutes later, he will find the wire.

“You have a little over an hour in which to contemplate your total extinction, an extinction which will remove from my path the one great obstacle to my domination of the world. I hope you will enjoy your remaining moments. In order to help you to enjoy them, and to realize the futility of human endeavor, I have placed the key of your shackles on the floor here in plain sight, but, alas, out of your reach. I would like to stay and watch your struggle, to see the self-control on which you pride yourself vanish, and to watch you whimper and pray for the mercy you would not find; but I am deprived of that pleasure. I must take personal charge of my men to be sure that there is no slip. Good-by, Doctor, we will never meet again, I fear.”

“We will meet again, Saranoff,” said Dr. Bird in even tones of cold ferocity which made even Saranoff shiver. “We will meet again, and when you whimper and beg for mercy, remember this moment!”

The Russian started forward with an oath, his hand raised to strike. He recovered himself and essayed a sickly smile.

“I will remember, Doctor,” he said in a voice which, despite himself, had a tremor of fear in it. “I will remember when we meet again.”

He ran lightly up the stairs and Dr. Bird heard the floor close above him. With a grunt, he bent down and examined his shackles closely. They were tight fitting and made of hardened steel. A cursory examination showed the doctor that he could neither force them nor slip them. He turned his attention to the key which Saranoff had pointed out. It lay on the floor, about ten feet, as nearly as he could judge, from where he stood.

He knelt and then stretched himself out at full length on the floor. By straining to the uttermost, his groping fingers were still six inches from the key. Saranoff had calculated the distance well.

Convinced that he could not reach the key by any effort of stretching, Dr. Bird wasted none of his precious time in vain regrets or in useless efforts to accomplish the impossible. He rose to his feet and calmly took stock of the room, searching for other means of freeing himself. The shackles themselves offered no hope. He searched his pockets. The search yielded a pocket knife, a bunch of keys, a flashlight, a handkerchief, a handful of loose change, and a wallet. He examined the miscellany thoughtfully.

A light broke over his face. He tied one end of the handkerchief to the knife and again took a prone position on the floor. Cautiously he tossed the knife out before him. It fell to one side of the key. He drew it back and tried again. The knife fell beyond the key. Slowly he drew it back toward him by the handkerchief. When it reached his hand, he saw to his joy, that the key was a good inch nearer. With a lighter heart, he tried again.

His toss was good. The knife fell over the key, and again he drew it to him. To his disgust, the key had not moved. Again and again he tried it, but the knife slid over the key without moving it. He looked more carefully and saw that the key was caught on an obstruction in the flooring.

With careful aim, he threw his knife so as to drive the key further away. He threw the knife again and tried to draw the key to him from its new position. It came readily until it reached the inequality in the floor which had stopped it the first time. All of his efforts to draw it nearer were fruitless. He give vent to a muttered oath as he looked at the clock. Thirty minutes of his time had gone.

A second time he knocked the key away and strove to draw it to him with no success. The clock bore witness to the fact that another ten minutes had been wasted. He rose to his feet and carefully surveyed his surroundings.

A cry of joy burst from his lips. On the floor was a tiny metallic thread which he knew for a wire. He bent down and picked it up. It was fine and very flexible. He doubled it three times and strove to bend a hook in it. The wire was too short to offer much hope, but he threw himself prone and began to fish for the key.

The wire reached it readily enough, but it did not have rigidity enough to pull the key over the little bump which held it. A glance at the clock threw him into an agony of despair. A full hour had passed since Saranoff had left him. Carnes might even now be walking into the trap which had been laid for him.

He rose to his feet and thought rapidly, twisting the wire idly around the knife as he did so. He glanced at the work of his hands, and an oath broke from his lip.

“Fool!” he exclaimed. “I deserve to die! The means for liberation were in my hands all the time.”

With feverish activity, he ripped open the flashlight. He held the two ends of the wire against the terminals of the light battery and touched the knife to his steel key ring. To his joy, the ring adhered to the knife. Under the influence of the battery, the wire-wrapped knife had become a small electromagnet.

In a moment the doctor was prone on the floor. He tossed the knife out to the key. His aim was good and it fell directly beyond. With trembling hands he drew the knife toward him. It reached the key. Scarcely daring to breathe, he pulled it closer. The key had risen over the ridge which had held it, and was adhering to the knife. In another moment, he stood erect, freed from the shackles which had bound him.

He made for the door at a run, but a sudden thought stopped him. The clock showed him that an hour and twenty minutes had passed.

“Carnes must be nearly here!” he cried. “If I go blundering out, I’m liable to run right into the trap they have laid for him, and then we’re both gone. If I yell to warn him, the fool will come ahead at full tilt. What the dickens can I do?”

His gaze fell on the can of radite. The wires leading to the interrupter fuse gleamed a dull gold with a malign significance.

“If Carnes and I are both washed out, there will be only Thelma left. She can’t fight Saranoff alone. Carnes knows the man and his methods. There is only one way that I can see to warn him out of the trap.”

He shuddered a moment. With a steady step he walked across the cave to the can of deadly explosive. A pair of pliers lay on a nearby bench. He picked them up. He dashed his hand across his face for a moment, but looked up with steady eyes. With hands that did not tremble, he bent down over the can. With a quick snip, he severed the wires leading to the can of radite.

Operative Carnes jumped ashore as the boat reached the bank of Bush River. Before him stretched a dismal swamp, interspersed with occasional bits of higher ground. He looked back over the river for a moment, taking his bearings with great care. A luminous lensatic compass gave him the orientation of the points he had chosen for markers.

“Are you sure we are at the right place?” he asked in an undertone.

“Sure as shootin’, Mister,” replied the boatman. “It’s the only place of its kind in five miles. The rock you’re hunting for is about a hundred rods due east.”

“It looks right,” said Carnes. “Come on, men.”

Operatives Haggerty and Dillon scrambled out of the boat and stood by his side.

“Follow me,” said Carnes in a whisper.

Both detectives nodded silently. They drew their pistols and fell in behind their leader. Keeping his direction with the aid of his compass, Carnes led the way forward, counting his steps. At five hundred he paused.

“It should be right here,” he whispered.

Haggerty pointed in silence. In the starlight, a large rock loomed up a few yards away. With an exclamation of satisfaction, Carnes led the way to it.

“Dig on the south side,” he whispered, “and hurry! The damned thing is due to go off in less than twenty minutes. Unless we can find and cut the wire before then, the doctor is a gone gosling.”

The two detectives drew intrenching shovels from their pockets and dug feverishly. For five minutes they labored. Dillon gave an exclamation.

“Here it is, Chief!” he said.

Carnes bent down and ventured a short flash from a carefully guarded light. The detective’s shovel had unearthed a powerful cable running through the earth.

“Get something to cut on!” cried Carnes.

Haggerty lifted a rock which they had unearthed and thrown to one side. Carnes raised the cable and laid it on the rock.

“Now for your ax, Dillon!” he exclaimed.

He turned on his flashlight. Dillon raised a hand-ax and took careful aim. Sparks flew as the ax fell on the rock, severing the cable cleanly. Carnes rose to his feet.

“The doctor’s safe!” he cried.

He started at a run toward the north. He had gone only a few feet when a beam of light flashed across the marsh, picking him out of the darkness. He paused in amazement.

A flash of orange light stabbed the darkness and a heavy pistol bullet sang past his head. The detective raised his weapon to reply, but three more flashes from the darkness were followed by the vicious cracks of large caliber automatics.

“Down, Chief!” cried Haggerty.

Carnes dropped to the ground, the beam of light following his movements. Four more flashes came from the darkness. Mud was thrown up into his face. Dillon’s gun joined Haggerty’s in barking defiance into the night.

A groan came from Haggerty.

“Hit, Tom?” asked Carnes anxiously.

“A little, but don’t let that bother you. Get that damned light!”

He fired again, groaning at he did so. There was a crash from over the marsh and the light went out.

“Good work, Tom!” cried Carnes.

He raised his pistol and fired again and again into the darkness, from which still came the flashes of orange light. A cry of pain rewarded him.

“Come on, men, rush them!” he cried.

He jumped to his feet and dashed forward. A fresh beam of light stabbed a path through the darkness. A volley of fire came from behind it. Haggerty stumbled and fell.

“They’ve got me, Chief!” he cried faintly.

Disregarding the storm of bullets, Carnes charged ahead, Dillon at his heels. A sudden shout came from his left. A fresh beam of light made a path through the darkness and Carnes could see his opponents lying prone on the marsh. A cry of dismay came from them. Carnes fired again as he rushed forward. The men leaped to their feet and fled away into the darkness.

“Your light, Dillon!” he cried.

Dillon’s light shone out and picked up one of the fleeing figures. The beam from the left was centered on another.

“Halt!” came a stern voice from behind the light. “You are surrounded! If I give the word to fire, you are dead men!”

“Dr. Bird!” cried Carnes in amazement.

The fleeing man in the beam of Dillon’s light paused.

“Drop your gun!” cried Carnes sharply.

There was a moment of hesitation before the man’s gun fell and his hands went up.

“Get him, Carnes!” came Dr. Bird’s voice. “I’ve got another one held out here. I hope one of them is the man we want.”

As Dillon slipped handcuffs on his prisoner, Dr. Bird came forward, driving another Russian before him. In his hand was a piece of iron pipe.

“Cuff him, Carnes!” he said.

The detective slipped handcuffs on the man while Dr. Bird bent down and examined the face of each of the prisoners with his light. He straightened up with an exclamation of anger.

“These are nothing but tools,” he said bitterly. “We had the arch-conspirator himself in our hands and let him escape.”

“The arch-conspirator!” gasped Carnes. “You don’t mean Saranoff?”

“Yes, Ivan Saranoff. He was here on this marsh to-night. There were four of his men and we got two, letting the most important one get away.”

“You’ve got four, Dr. Bird,” said a guttural voice from the dark.

Dr. Bird whirled around and shot out the beam of his light. A third Russian was revealed in its gleam.

“Hands up!” cried the doctor.

“I’m willing to be captured, Doctor,” said the Russian. “Your search for Saranoff is useless. He has been gone for an hour. He is not one to risk his own skin when others will risk theirs for him. He fled after he left the cave.”

“Do you know where he has gone?”

“I wish I did, Doctor. If I knew, we’d soon have him, I hope.”

The Russian’s voice had changed entirely. Gone were the heavy guttural tones. In their place was a rich, rather throaty contralto. Carnes gave a cry of astonishment and turned his light on the prisoner.

“Thelma!” he gasped.

The Russian smiled.

“Surely, Mr. Carnes,” she said. “Congratulations on your acumen. Dr. Bird saw me for half an hour this evening, but he didn’t recognize me. He even knocked me out with his fist back in the cavern.”

“The devil I did!” gasped the doctor. “What were you doing there?”

“Helping Saranoff capture you, Doctor,” she replied. “The day you left, I saw one of his men on the street. I dared not summon help lest he should escape, so I followed him. I captured him and learned from him the location of the gang headquarters.

“I disguised myself and took his place for a week, fooling them all, even Saranoff himself. I was one of those chosen to carry out your capture and your murder. This afternoon, unknown to Saranoff, I tampered with that radite can and removed the fuse. That was why there was no explosion when Mr. Carnes cut the wire. I had no chance to warn him. I managed to shoot one of Saranoff’s men when they broke and ran.”

Her voice trembled in the darkness.

“I hated to kill him ” she said with a half sob.

A faint hail came from the night.

“Haggerty!” cried Carnes.

“All right, Chief,” came Dillon’s voice. “He’s got a bullet in his shoulder and one through his leg, but no bones broken. He’ll be all right.”

Carnes turned again to the girl.

“What about that Russian whose place you took?” he asked. “Maybe we can pump something out of him.”

Thelma swayed for a moment.

“Don’t, Mr. Carnes,” she cried, her voice rising almost to a shriek. “Don’t make me think of it! I I had to to stab him!”

She swayed again. Carnes started toward her, his arms outstretched. Dr. Bird’s voice stopped him.

“Miss Andrews,” said the doctor sternly, “you know that I demand control of the emotions from all my subordinates. You are crying like a hysterical schoolgirl. Unless you can learn to control your feelings instead of giving way to them on every occasion, I will have to dispense with your further services.”

The girl swayed toward him for a moment, a look of pain in her eyes. She shuddered and then recovered herself. She straightened up and faced Dr. Bird boldly.

“Yes, Doctor,” came in level expressionless tones from her lips.