"A plane is waiting for us at Langley Field. I want to look over the coast in the vicinity of Charleston Harbor and some of the sounds near there. If he is using a sub, he must have a base somewhere."
With a competent pilot at the stick, Carnes and the Doctor spent the day in exploring. The day yielded no results, and with the coming of dusk they landed at Savannah for the night. Carnes talked with Bolton over the telephone, but the secret service chief could report no favorable progress. Tired and disgusted, they retired early, but they were not destined to enjoy a night of uninterrupted sleep. At one o'clock a telegram was brought to their room. Dr. Bird tore it open and glanced sleepily at it.
"Get up, Carnes," he cried sharply. "Read this!"
The yawning detective glanced at the telegram. It contained only two words and a signature. It was signed "Ivan," and read simply, "Watch Wilmington."
"What the dickens?" he exclaimed as he studied the yellow slip. Dr. Bird was hurriedly pulling on his clothes.
"Saranoff has slipped a cog this time," said the doctor. "He sent that as a night message, but it was delivered as a straight message through error. He has got further north than I expected. We will turn out our pilot and take off. We should make Wilmington by daybreak. I'll telephone Washington and have a couple of destroyers started up Delaware Bay at once. We ought to give him a first class surprise party. I suppose that Philadelphia was meant to be his next stop."
In an hour the army plane took off into the night. At seven o'clock they were circling over Wilmington. The city had not been disturbed. For an hour they flew back and forth before they landed. Startling news awaited them. At six that morning an earthquake had struck Wilmington, North Carolina. Half the town had sunk into the earth. Dr. Bird struck his brow with his clenched fist.
"Score one for the enemy," he said grimly. "We were too sure of ourselves, Carnes. We should have realized that he would hardly be so far north yet. Well, I've got to use the telephone while we're refueling."
Within an hour after landing they were again in the air One o'clock found them over the stricken city. Dr. Bird wasted no time on Wilmington but headed north along the coast. For a hundred miles he skirted the shore, two miles out. With an exclamation of disappointment he ordered the pilot to turn the plane and retrace his route southward, keeping ten miles from the shore. Fifty miles south he ordered the plane further out and again turned north. From time to time they passed a ship of the air patrol which was steadily skirting the coast, but none of them had seen a submarine. Off Cape Hatteras the pilot asked for orders.
"The gas is running low. Doctor," he said. "I think we had better put in somewhere and refuel. If we are going to keep the air much longer, you had better get a relief pilot. I have been flying for thirty hours out of the last thirty-six and I'm about done."
"Head back for Washington," said the doctor with a sigh. "I seem to have gone off on a false scent."
At Cape Charles the pilot swung east over Chesapeake Bay. Hardly had he turned than Dr. Bird gave a cry. Excitedly he pointed toward the water. Carnes grasped a pair of binoculars and looked in the direction Dr. Bird was indicating. Sliding along under the water was a long cigar-shaped shadow.
"It's a submarine!" exclaimed Carnes. "Is it a navy ship or the one we're after?"
"It's no navy sub," said the doctor positively. "It's not the right shape. Look at that bump on the side!"
The symmetry of the craft was marred by a huge projection on one side that could not be explained by the pattern of any known type of under-water craft.
"He's towing the borer!" cried the doctor in exultation. He took up the speaking tube. "Turn back to sea!" he cried. "We passed four destroyers less than ten miles out. We want to get in touch with them."
The plane roared out to sea while Dr. Bird feverishly sounded the "Alnav" call on the radio sending set. In a few minutes an answer came. From their point of vantage they could see flags break out at the peak of the destroyer leader. The four ships turned into column formation and stormed at full speed into the bay. The plane raced ahead to guide them.
"We've got him this time, Doctor!" cried Carnes in exultation. He pointed to the bay below where the submarine was still making its way slowly forward. Dr. Bird shook his head.
"I hope so," he said, "but I have my doubts. Saranoff is no fool. He wouldn't walk into a trap like this unless he had some means of escape. Here comes the first destroyer. We'll soon know the truth."
With the radio set he directed the oncoming boat. The destroyer reduced to half speed and changed direction slightly. From side to side she maneuvered until she was less than half a mile behind the submarine and headed straight for it. Dr. Bird tapped a few words on his key. With a belch of smoke, the destroyer lurched forward. She cut the waters with her sharp bow, throwing up a wave higher than her decks. Dr. Bird watched anxiously.
The destroyer was almost over the submarine and Dr. Bird's fingers trembled on the key. One word from him would send a half dozen depth charges into the water. On came the destroyer until it was directly over the underseas craft. Dr. Bird pounded his key rapidly.
"Good Lord!" cried Carnes.
From the bump on the side of the submarine came a flash of red light. The destroyer staggered for a moment, and the entire central section of the ill-fated ship disappeared. The bow and stern came together with a rush and went down in a swirling maelstrom of water. The plane lurched in the air as a thundering crash rose from the sea.
The second destroyer, in no way daunted by the fate of her colleague, rushed to the attack. Dr. Bird pounded his key frantically in an attempt to turn her back. His message was too late or was misunderstood. Straight over the submarine went the second ship. Again came the red flash. The forward half of the destroyer disappeared and the stern slid down into a huge hole which had opened in the water.
"He's invulnerable!" cried the doctor. He pounded his key with feverish rapidity. The two remaining destroyers slackened speed and veered off. Slowly, as though loath to turn their backs on the enemy, they headed out for the broad Atlantic and comparative safety.
The submarine went slowly on her way. She did not turn west at the mouth of the Potomac but continued on up the bay. As long as there was light enough, the doctor's plane kept above her but the fading light soon made it impossible to see her. When she had disappeared from view, the doctor reluctantly gave the word to return to Washington.
"Where do you suppose he will attack next, Doctor?" asked Carnes when they sat again in the doctor's private laboratory.
"Washington, of course," said Dr. Bird absently as he looked up from a pile of telegrams he was running through.
"Use your head. Representatives of every civilized power are in Washington now at the President's invitation to consider means of halting the anti-religious activities of the Soviets. The destruction of the city and the killing of these men would be a telling blow for Russia to strike."
"But, Doctor, you don't think--"
"Excuse me, Carnes; that will keep. Let me read these telegrams."
For half an hour silence reigned in the laboratory. Dr. Bird laid down the last message with a sigh.
"Carnes," he said, "I'm check-mated. I sent out a hundred ultra-sensitive short wave receivers yesterday. Four of them were located within fifty miles of Wilmington, North Carolina. One of these four was destroyed, but none of the others detected a sign of a wave during the attack. One of them was within a hundred feet of the edge of the hole. If he isn't using a ray of some sort, what on earth is he using?"
"It looked like a flash of red light when it came from the submarine."
"Yes, but it couldn't be light. Let me think."
The doctor sat for a few minutes with corrugated brows. Suddenly he sprang to his feet.
"I deserve to be beaten," he cried. "Why didn't I think of that possibility before?"
He hurried into his laboratory and brought out a small box with a glass front. From the top projected a spike topped with a ball. Through the glass, Carnes could see a thin sheet of metal hanging pendant from the spike.
"An electroscope," explained the doctor. "That sheet of metal is really two sheets of gold-leaf, at present stuck together. If I rub a piece of hard rubber with a woolen cloth, the rod will become charged with static electricity. If I then touch the ball with it, the charge is transferred to the electroscope and causes the two sheets of gold-leaf to stand apart at an angle. Watch me."
He took a hard rubber rod and rubbed it briskly on his coat sleeve. As he touched the ball of the electroscope the sheets of gold-leaf separated and stood apart at a right angle.
"As long as the air remains non-conducting, the two bits of gold-leaf will hold that position. The air, however, is not a perfect insulator and the charge will gradually leak off. If I bring a bit of radioactive substance, for instance, pitchblende, near the electroscope, the charge will leak rapidly. Do you understand?"
"Yes, but how is that going to help us?"
"Saranoff is accomplishing his result by artificially compressing the atoms. It is inevitable that he will do it imperfectly, and some electrons will be loosened and escape. These electrons, traveling up through the earth will make the air conducting. To-morrow we will have a means of locating the borer under ground."
"Once you locate it, how will you fight it?"
"That is the problem I must work out to-night."
"Could we bury a charge of explosive and blow it up?"
"Ordinary explosives would be useless," the doctor answered. "They would react in the same manner as other substances, and would be rendered harmless. Radite might do the work if it could be placed in the path, but it couldn't be. We may locate the position and depth of the borer, but long before we could dig and blast a hole deep enough to place a charge of radite before it, it would have passed on or changed direction. No, Carnes, old dear, the only solution that I can see is to turn his own guns on him. If I can, before morning, duplicate his device, we can train it on the spot where he is and reduce him and his machine to a pinch of yellow powder."
"Can you do it, Doctor?"
"What one man's brain can device, another man's brain can duplicate. The only question is that of time. I am confident that Saranoff will attack Washington to-morrow. If I can do the job to-night, we may save the city. If not--At any rate, Carnes, your job will be to see that the President and all of the heads of the government are out of the city by morning. The President may refuse to leave. Knowing him as I do, I rather expect he will."
"In that case, the issue is in the hands of the gods. Now get out of here. I want to work. Report back at daybreak with a car."
Dr. Bird turned back to his laboratory.
"He must be using a ray of some sort, possibly a radium emanation," he muttered to himself. "That would have no wave motion and might accomplish the result, although I would expect the exact opposite from it. The first thing to do is to examine that powder with a spectroscope and see if I can get a clue to the electronic arrangement."
When Carnes arrived at the Bureau of Standards at dawn be rubbed his eyes in astonishment. The buildings were lighted up and the grounds swarmed with workmen. Before the buildings were lined up a dozen trucks and twice that many touring cars. A cordon of police held back the curious. Carnes' gold badge won him an entrance and he hurried up the stairs to Dr. Bird's laboratory. The doctor's face was drawn and haggard, but his eyes glowed with a feverish light. Workmen were carrying down huge boxes.
"What's up, Doctor?" demanded the detective.
"Oh, you got here at last, did you? You're just in time. If you'd been fifteen minutes later, you would have found us gone."
"Out into Maryland in an attempt to stop Saranoff in his progress toward Washington."
"Have you found your means of combating him?"
"I hope so, although it is not what I started out to get. Did you bring a car as I told you?"
"It's waiting below."
"Good enough. I'll go in it. Williams, are those projectors all loaded?"
"Yes, Dr. Bird. The magnet will be ready to go in five minutes. The electroscopes and the other light stuff are all loaded and ready to move."
"You have done well. I'll let you bring the trucks and heavy equipment while I go ahead with the instruments. Take the road out toward Upper Marlboro. If I don't meet you before, stop there for orders."
"Very well, Doctor."
"Come on, Carnes, let's go."
He raced down the stairs with the detective at his heels. He went along the line of touring cars and spoke briefly to the drivers. He climbed into the car which Carnes had brought. As it started the other cars fell in behind it. At a speed of forty miles an hour, with a detachment of motorcycle police leading the van, the cavalcade rolled out through the deserted streets of Washington. Once clear of the city, the speed was increased.
"Did you persuade the President to leave?" asked the doctor.
"There wasn't a chance. The papers panned him so much for following my advice at Charleston that he has turned stubborn. He says that if all the forces of the government can't protect him against one man, he is willing to die."
"We've got to save him," said Dr. Bird grimly. "Hello, there's the Chesapeake ahead."
The doctor studied the country.
"We are about opposite the place where we left that sub last night. I fancy that Saranoff will operate from there, for it didn't move during the last half hour we watched it. We'll go back inland a mile or two and spread out. I have no idea how far his radiations will affect the electroscopes, but we'll try four hundred-yard intervals to start. That will enable us to cover a line twelve miles long."
He picked up a megaphone and spoke to the line of cars behind him.
"Take up four hundred yard intervals when we spread out," he said. "Every man keep his headphone on and listen for orders. Follow my car until it stops, then turn north and south and drop your men at intervals."
He reentered the car and led the way back for two miles. He halted his car at a crossroad. The cars following him turned and went to the north and south. Besides Carnes and the doctor, the car held two men from the Bureau. As they climbed out, Carnes saw that one of them carried a portable radio sending set, while the other bore an electroscope and a rubber rod. The radio operator set up his device, while the other man rubbed his coat sleeve briskly with the hard rubber and then touched the ball of the electroscope with it. The two bits of gold-leaf spread out.
"While we're waiting, I'll explain something of this to you, Carnes," said the doctor. "At four hundred-yard intervals are men with electroscopes like this one. My attempt to locate Saranoff by means of wave detectors was a failure. That proved that the ray he was using is not of the wave type. The other common ray is the cathode ray type which does not consist of vibrations but of a stream of electrons, negative particles of electricity, traveling in straight lines of high velocity. He must be knocking loose some of the electrons when he collapses the atoms. The rate of discharge of these electroscopes will give us a clue to the nearness of his device."
"Once you locate him, how do you propose to attack him?"
"The obvious method, that of using his own ray against him, fell down. However, in attempting to produce it, I stumbled on another weapon which may be equally effective. I am going to try to use an exact opposite of his ray. The cathode ray, when properly used, will bombard the atoms and knock electrons loose. I perfected last night a device on which I have been working for months. It is a super-cathode ray. I tested it on the yellow powder and find that I can successfully reverse Saranoff's process. He can contract matter together until it occupies less than one one-thousandth of its original volume. My ray will destroy this effect and restore matter to something like its original condition."
"And the effect will be?"
"Use your imagination. He blasts out a hole by condensing the rock to a pinch of yellow powder. He moves forward into the hole he has made. I come along and reverse his process. The yellow powder expands to its original volume and the hole he has made ceases to exist. What must happen to the foreign body which had been introduced into the hole that is no longer a hole?"
"At any rate, I hope that I am never in a hole when that happens."
"And I devoutly hope that Saranoff is. I met with one difficulty. My ray will not penetrate the depth of solid rock which separates his borer from the surface."
"Then how will you reach him to crush him? You don't expect to drill down ahead of him?"
"That is my stroke of genius, Carnes. I am going to make him bore the hole down which my ray will travel to accomplish his destruction. The cathode ray and rays of that type--"
"Pardon me, Doctor," interrupted the radio operator. "I have just received a message from the squadron leader of the planes patrolling the bay. He states that every inch of the Chesapeake Bay and the Potomac River have been examined and no submarine is visible."
"I expected that. He will have opened a cavern under the earth, in which his craft is safe from aerial observation. Once the borer has left it, it is invulnerable no longer."
"What reply shall I make?"
"Tell him to keep up a constant patrol. Three navy subs with radite-charged torpedos are on their way up the bay, together with half a dozen destroyers. The subs will scout for such a hole as I have described and will attack his sub if they find it. The destroyers will stand by and support them."
The operator turned to his instrument. The electroscope observer claimed the doctor's attention.