“Confound it, Carnes, I am on my vacation!”

“I know it, Doctor, and I hate to disturb you, but I felt that I simply had to. I have one of the weirdest cases on my hands that I have ever been mixed up in and I think that you’ll forgive me for calling you when I tell you about it.”

Dr. Bird groaned into the telephone transmitter.

“I took a vacation last summer, or tried to, and you hauled me away from the best fishing I have found in years to help you on a case. This year I traveled all the way from Washington to San Francisco to get away from you and the very day that I get here you are after me. I won’t have anything to do with it. Where are you, anyway?”

“I am at Fallon, Nevada, Doctor. I’m sorry that you won’t help me out because the case promises to be unusually interesting. Let me at least tell you about it.”

Dr. Bird groaned louder than ever into the telephone transmitter.

“All right, go ahead and tell me about it if it will relieve your mind, but I have given you my final answer. I am not a bit interested in it.”

“That is quite all right, Doctor, I don’t expect you to touch it. I hope, however, that you will be able to give me an idea of where to start. Did you ever see a man’s body broken in pieces?”

“Do you mean badly smashed up?”

“No indeed, I mean just what I said, broken in pieces. Legs snapped off as though the entire flesh had become brittle.”

“No, I didn’t, and neither did anyone else.”

“I have seen it, Doctor.”

“Hooey! What had you been drinking?”

Operative Carnes of the United States Secret Service chuckled softly to himself. The voice of the famous scientist of the Bureau of Standards plainly showed an interest which was quite at variance with his words.

“I was quite sober, Doctor, and so was Hughes, and we both saw it.”

“Who is Hughes?”

“He is an air mail pilot, one of the crack fliers of the Transcontinental Airmail Corporation. Let me tell you the whole thing in order.”

“All right. I have a few minutes to spare, but I’ll warn you again that I don’t intend to touch the case.”

“Suit yourself, Doctor. I have no authority to requisition your services. As you know, the T. A. C. has been handling a great deal of the transcontinental air mail with a pretty clean record on accidents. The day before yesterday, a special plane left Washington to carry two packages from there to San Francisco. One of them was a shipment of jewels valued at a quarter of a million, consigned to a San Francisco firm and the other was a sealed packet from the War Department. No one was supposed to know the contents of that packet except the Chief of Staff who delivered it to the plane personally, but rumors got out, as usual, and it was popularly supposed to contain certain essential features of the Army’s war plans. This much is certain: The plane carried not only the regular T. A. C. pilot and courier, but also an army courier, and it was guarded during the trip by an army plane armed with small bombs and a machine-gun. I rode in it. My orders were simply to guard the ship until it landed at Mills Field and then to guard the courier from there to the Presidio of San Francisco until his packet was delivered personally into the hands of the Commanding General of the Ninth Corps Area.

“The trip was quiet and monotonous until after we left Salt Lake City at dawn this morning. Nothing happened until we were about a hundred miles east of Reno. We had taken elevation to cross the Stillwater Mountains and were skimming low over them, my plane trailing the T. A. C. plane by about half a mile. I was not paying any particular attention to the other ship when I suddenly felt our plane leap ahead. It was a fast Douglas and the pilot gave it the gun and made it move, I can tell you. I yelled into the speaking tube and asked what was the reason. My pilot yelled back that the plane ahead was in trouble.

“As soon as it was called to my attention I could see myself that it wasn’t acting normally. It was losing elevation and was pursuing a very erratic course. Before we could reach it it lost flying speed and fell into a spinning nose dive and headed for the ground. I watched, expecting every minute to see the crew make parachute jumps, but they didn’t and the plane hit the ground with a terrific crash.”

“It caught fire, of course?”

“No, Doctor, that is one of the funny things about the accident. It didn’t. It hit the ground in an open place free from brush and literally burst into pieces, but it didn’t flame up. We headed directly for the scene of the crash and we encountered another funny thing. We almost froze to death.”

“What do you mean?”

“Exactly what I say. Of course, it’s pretty cold at that altitude all the time, but this cold was like nothing I had ever encountered. It seemed to freeze the blood in our veins and it congealed frost on the windshields and made the motor miss for a moment. It was only momentary and it only existed directly over the wrecked plane. We went past it and swung around in a circle and came back over the wreck, but we didn’t feel the cold again.

“The next thing we tried to do was to find a landing place. That country is pretty rugged and rough and there wasn’t a flat place for miles that was large enough to land a ship on. Hughes and I talked it over and there didn’t seem to be much of anything that we could do except to go on until we found a landing place. I had had no experience in parachute jumping and I couldn’t pilot the plane if Hughes jumped. We swooped down over the wreck as close as we dared and that was when we saw the condition of the bodies. The whole plane was cracked up pretty badly, but the weird part of it was the fact that the bodies of the crew had broken into pieces, as though they had been made of glass. Arms and legs were detached from the torsos and lying at a distance. There was no sign of blood on the ground. We saw all this with our naked eyes from close at hand and verified it by observations through binoculars from a greater height.

“When we had made our observations and marked the location of the wreck as closely as we could, we headed east until we found a landing place near Fallon. Hughes dropped me here and went on to Reno, or to San Francisco if necessary, to report the accident and get more planes to aid in the search. I was wholly at sea, but it seemed to be in your line and as I knew that you were at the St. Francis, I called you up.”

“What are your plans?”

“I made none until I talked with you. The country where the wreck occurred is unbelievably wild and we can’t get near it with any transportation other than burros. The only thing that I can see to do is to gather together what transportation I can and head for the wreck on foot to rescue the packets and to bring out the bodies. Can you suggest anything better?”

“When do you expect to start?”

“As soon as I can get my pack train together. Possibly in three or four hours.”

“Carnes, are you sure that those bodies were broken into bits? An arm or a leg might easily be torn off in a complete crash.”

“They were smashed into bits as nearly as I could tell, Doctor. Hughes is an old flier and he has seen plenty of crashes but he never saw anything like this. It beats anything that I ever saw.”

“If your observations were accurate, there could be only one cause and that one is a patent impossibility. I haven’t a bit of equipment here, but I expect that I can get most of the stuff I want from the University of California across the bay at Berkeley. I can get a plane at Crissy Field. I’ll tell you what to do, Carnes. Get your burro train together and start as soon as you can, but leave me half a dozen burros and a guide at Fallon. I’ll get up there as soon as I can and I’ll try to overtake you before you get to the wreck. If I don’t, don’t disturb anything any more than you can help until my arrival. Do you understand?”

“I thought that you were on your vacation, Doctor.”

“Oh shut up! Like most of my vacations, this one will have to be postponed. I’ll move as swiftly as I can and I ought to be at Fallon to-night if I’m lucky and don’t run into any obstacles. Burros are fairly slow, but I’ll make the best time possible.”

“I rather expected you would, Doctor. I can’t get my pack train together until evening, so I’ll wait for you right here. I’m mighty glad that you are going to get in on it.”

Silently Carnes and Dr. Bird surveyed the wreck of the T. A. C. plane. The observations of the secret service operative had been correct. The bodies of the unfortunate crew had been broken into fragments. Their limbs had not been twisted off as a freak of the fall but had been cleanly broken off, as though the bodies had suddenly become brittle and had shattered on their impact with the ground. Not only the bodies, but the ship itself had been broken up. Even the clothing of the men was in pieces or had long splits in the fabric whose edges were as clean as though they had been cut with a knife.

Dr. Bird picked up an arm which had belonged to the pilot and examined it. The brittleness, if it had ever existed, was gone and the arm was limp.

“No rigor mortis,” commented the Doctor. “How long ago was the wreck?”

“About seventy-two hours ago.”

“Hm-m! What about those packets that were on the plane?”

Carnes stepped forward and gingerly inspected first the body of the army courier and then that of the courier of the T. A. C.

“Both gone, Doctor,” he reported, straightening up.

Dr. Bird’s face fell into grim lines.

“There is more to this case than appears on the surface, Carnes,” he said. “This was no ordinary wreck. Bring up that third burro; I want to examine these fragments a little. Bill,” he went on to one of the two guides who had accompanied them from Fallon, “you and Walter scout around the ground and see what you can find out. I especially wish to know whether anyone has visited the scene of the wreck.”

The guides consulted a moment and started out. Carnes drove up the burro the Doctor had indicated and Dr. Bird unpacked it. He opened a mahogony case and took from it a high powered microscope. Setting the instrument up on a convenient rock, he subjected portions of the wreck, including several fragments of flesh, to a careful scrutiny. When he had completed his observations he fell into a brown study, from which he was aroused by Carnes.

“What did you find out about the cause of the wreck, Doctor?”

“I don’t know what to think. The immediate cause was that everything was frozen. The plane ran into a belt of cold which froze up the motor and which probably killed the crew instantly. It was undoubtedly the aftermath of that cold which you felt when you swooped down over the wreck.”

“It seems impossible that it could have suddenly got cold enough to freeze everything up like that.”

“It does, and yet I am confident that that is what happened. It was no ordinary cold, Carnes; it was cold of the type that infests interstellar space; cold beyond any conception you have of cold, cold near the range of the absolute zero of temperature, nearly four hundred and fifty degrees below zero on the Fahrenheit scale. At such temperatures, things which are ordinarily quite flexible and elastic, such as rubber, or flesh, become as brittle as glass and would break in the manner which these bodies have broken. An examination of the tissues of the flesh shows that it has been submitted to some temperature that is very low in the scale, probably below that of liquid air. Such a temperature would produce instant death and the other phenomena which we can observe.”

“What could cause such a low temperature, Doctor?”

“I don’t know yet, although I hope to find out before we are finished. Cold is a funny thing, Carnes. Ordinarily it is considered as simply the absence of heat; and yet I have always held it to be a definite negative quantity. All through nature we observe that every force has its opposite or negative force to oppose it. We have positive and negative electrical charges, positive and negative, or north and south, magnetic poles. We have gravity and its opposite apergy, and I believe cold is really negative heat.”

“I never heard of anything like that, Doctor. I always thought that things were cold because heat was taken from them--not because cold was added. It sounds preposterous.”

“Such is the common idea, and yet I cannot accept it, for it does not explain all the recorded phenomena. You are familiar with a searchlight, are you not?”

“In a general way, yes.”

“A searchlight is merely a source of light, and of course, of heat, which is placed at the focus of a parabolic reflector so that all of the rays emanating from the source travel in parallel lines. A searchlight, of course, gives off heat. If we place a lens of the same size as the searchlight aperture in the path of the beam and concentrate all the light, and heat, at one spot, the focal point of the lens, the temperature at that point is the same as the temperature of the source of the light, less what has been lost by radiation. You understand that, do you not?”

“Certainly.”

“Suppose that we place at the center of the aperture of the searchlight a small opaque disc which is permeable neither to heat nor light, in such a manner as to interrupt the central portion of the beam. As a result, the beam will go out in the form of a hollow rod, or pipe, of heat and light with a dark, cold core. This core will have the temperature of the surrounding air plus the small amount which has radiated into it from the surrounding pipe. If we now pass this beam of light through a lens in order to concentrate the beam, both the pipe of heat and the cold core will focus. If we place a temperature measuring device near the focus of the dark core, we will find that the temperature is lower than the surrounding air. This means that we have focused or concentrated cold.”

“That sounds impossible. But I can offer no other criticism.”

“Nevertheless, it is experimentally true. It is one of the facts which lead me to consider cold as negative heat. However, this is true of cold, as it is of the other negative forces; they exist and manifest themselves only in the presence of the positive forces. No one has yet concentrated cold except in the presence of heat, as I have outlined. How this cold belt which the T. A. C. plane encountered came to be there is another question. The thing which we have to determine is whether it was caused by natural or artificial forces.”

“Both of the packets which the plane carried are gone, Doctor,” observed Carnes.

“Yes, and that seems to add weight to the possibility that the cause was artificial, but it is far from conclusive. The packets might not have been on the men when the plane fell, or someone may have passed later and taken them for safekeeping.”

The doctor’s remarks were interrupted by the guides.

“Someone has been here since the wreck, Doctor,” said Bill. “Walter and I found tracks where two men came up here and prowled around for some time and then left by the way they came. They went off toward the northwest, and we followed their trail for about forty rods and then lost it. We weren’t able to pick it up again.”

“Thanks, Bill,” replied the doctor. “Well, Carnes, that seems to add more weight to the theory that the spot of cold was made and didn’t just happen. If a prospecting party had just happened along they would either have left the wreck alone or would have made some attempt to inter the bodies. That cold belt must have been produced artificially by men who planned to rob this plane after bringing it down and who were near at hand to get their plunder. Is there any chance of following that trail?”

“I doubt it, Doc. Walter and I scouted around quite a little, but we couldn’t pick it up again.”

“Is there any power line passing within twenty miles of here?”

“None that Walter and I know of, Doc.”

“Funny! Such a device as must have been used would need power and lots of it for operation. Well, I’ll try my luck. Carnes, help me unpack and set up the rest of my apparatus.”

With the aid of the operative, Dr. Bird unpacked two of the burros and extracted from cases where they were carefully packed and padded some elaborate electrical and optical apparatus. The first was a short telescope of large diameter which he mounted on a base in such a manner that it could be elevated or depressed and rotated in any direction. At the focal point of the telescope was fastened a small knot of wire from which one lead ran to the main piece of apparatus, which he sat on a flat rock. The other lead from the wire knot ran into a sealed container surrounded by a water bath under which a spirit lamp burned. From the container another lead led to the main apparatus. This main piece consisted of a series of wire coils mounted on a frame and attached to the two leads. The doctor took from a padded case a tiny magnet suspended on a piece of wire of exceedingly small diameter which he fastened in place inside the coils. Cemented to the magnet was a tiny mirror.

“What is that apparatus?” asked Carnes as the doctor finished his set-up and surveyed it with satisfaction.

“Merely a thermocouple attached to a D’Arsonval galvanometer,” replied the doctor. “This large, squat telescope catches and concentrates on the thermocouple and the galvanometer registers the temperature.”

“You’re out of my depth. What is a thermocouple?”

“A juncture of two wires made of dissimilar metals, in this case of platinum and of platinum-iridium alloy. There is another similar junction in this case, which is kept at a constant temperature by the water bath. When the temperatures of the two junctions are the same, the system is in equilibrium. When they are at different temperatures, an electrical potential is set up, which causes a current to flow from one to the other through the galvanometer. The galvanometer consists of a magnet set up inside coils through which the current I spoke of flows. This current causes the magnet to rotate and by watching the mirror, the rotation can be detected and measured.

“This device is one of the most sensitive ever made, and is used to measure the radiation from distant stars. Currents as small as .000000000000000000000000001 ampere have been detected and measured. This particular instrument is not that sensitive to begin with, and has its sensitivity further reduced by having a high resistance in one of the leads.”

“What are you going to use it for?”

“I am going to try to locate somewhere in these hills a patch of local cold. It may not work, but I have hopes. If you will manipulate the telescope so as to search the hills around here, I will watch the galvanometer.”

For several minutes Carnes swung the telescope around. Twice Dr. Bird stopped him and decreased the sensitiveness of his instrument by introducing more resistance in the lines in order to keep the magnet from twisting clear around, due to the fluctuations in the heats received on account of the varying conditions of reflection. As Carnes swung the telescope again the magnet swung around sharply, nearly to a right angle to its former position.