a few drops of this,” he advised.
With an effort the man lifted the flask to his lips and gulped down a little of the fiery spirit. A sound of tramping feet came from the outside and then a thud as though a body had been dropped. Carnes and Walter entered the cabin.
“He’s dead as a mackerel,” said Carnes in answer to the doctor’s look. “Walter got him through the neck and broke his spinal cord. He never knew what hit him.”
“The plans?” came in a gasping voice from the man in the corner.
“We got them, too,” replied Carnes. “He had both packets inside his coat. They have been opened, but I guess they are all here. Who the devil are you?”
“Since Koskoff is dead, and I am dying, there is no reason why I shouldn’t tell you,” was the answer. “Leave that brandy handy to keep up my strength. I have only a short time and I can’t repeat.
“As to who I am or what I was, it doesn’t really matter. Koskoff knew me as John Smith, and it will pass as well as any other name. Let my past stay buried. I am, or was, a scientist of some ability; but fortune frowned on me, and I was driven out of the world. Money would rehabilitate me–money will do anything nowadays–so I set out to get it. In the course of my experimental work, I had discovered that cold was negative heat and reacted to the laws which governed heat.”
“I knew that,” cried Dr. Bird; “but I never could prove it.”
“Who are you?” demanded John Smith.
“Dr. Bird, of the Bureau of Standards.”
“Oh, Bird. I’ve heard of you. You can understand me when I say that as heat, positive heat is a concomitant of ordinary light. I have found that cold, negative heat, is a concomitant of cold light. Is my apparatus in good shape outside?”
“The reflector is smashed.”
“I’m sorry. You would have enjoyed studying it. I presume that you saw that it was a catenary curve?”
“I rather thought so.”
“It was, and it was also adjustable. I could vary the focal point from a few feet to several miles. With that apparatus I could throw a beam of negative heat with a focal point which I could adjust at will. Close to the apparatus, I could obtain a temperature almost down to absolute zero, but at the longer ranges it wasn’t so cold, due to leakage into the atmosphere. Even at two miles I could produce a local temperature of three hundred degrees below zero.”
“What was the source of your cold?”
“Liquid helium. Those cylinders contain, or rather did contain, for I expect that Koskoff has emptied them, helium in a liquid state.”
“Where is your compressor?”
“I didn’t have to use one. I developed a cold light under whose rays helium would liquefy and remain in a state of equilibrium until exposed to light rays. Those cylinders had merely enough pressure to force the liquid out to where the sun could hit it, and then it turned to a gas, dropping the temperature at the first focal point of the reflector to absolute zero. When I had this much done, Koskoff and I packed the whole apparatus here and were ready for work.
“We were on the path of the transcontinental air mail, and I bided my time until an especially valuable shipment was to be made. My plans, which worked perfectly, were to freeze the plane in midair and then rob the wreck. I heard of the jewel shipment the T. A. C. was to carry and I planned to get it. When the plane came over, Koskoff and I brought it down. The unsuspected presence of another plane upset us a little, and I started to bring it down. But we had been all over this country and knew there was no place that a plane could land. I let it go on in safety.”
“Thank you,” replied Carnes with a grimace.
“We robbed the wreck and we found two packets, one the jewels I was after, and the other a sealed packet, which proved to contain certain War Department plans. That was when I learned who Koskoff was. I had hired him in San Francisco as a good mechanic who had no principles. He was to get one-fourth of the loot. When we found these plans, he told me who he was. He was really a Russian secret agent and he wanted to deliver the plans to Russia. I may be a thief and a murderer, but I am not yet ready to betray my country, and I told him so. He offered me almost any price for the plans; but I wouldn’t listen. We had a serious quarrel, and he overpowered me and bound me.
“We had a radio set here and he called San Francisco and sent some code message. I think he was waiting here for someone to come. Had we followed our original plans, we would have been miles from here before you arrived.
“He had me bound and helpless, as he thought, but I worked my bonds a little loose. I didn’t let him know it, for I knew that the plane I had let get away would guide a party here and I thought I might be able to help out. When you came and attacked the house, I worked at my bonds until they were loose enough to throw off. I saw Koskoff start my cold apparatus to working and then he quit, because he ran out of helium. When he started shooting again, I worked out of my bonds and tackled him.
“He was a better man than I gave him credit for, or else he suspected me, for about the time I grabbed him he whirled and struck me over the head with his gun barrel and tore my face open. The blow stunned me, and when I came to, I was thrown into this corner. I meant to have another try at it, but I guess you rushed him too fast. He turned and ran for the tunnel, but as he did so, he shot me through the body. I guess I didn’t look dead enough to suit him. You gentlemen broke open the door and came in. That’s all.”
“Not by a long shot, it isn’t,” exclaimed Dr. Bird. “Where is that cold light apparatus of yours?”
“In the tunnel.”
“How do you get into it?”
“If you will open that cupboard on the wall, you’ll find an open knife switch on the wall. Close it.”
Dr. Bird found the switch and closed it. As he did so the cabin rocked on its foundations and both Carnes and Walter were thrown to the ground. The thud of a detonation deep in the earth came to their ears.
“What was that?” cried the doctor.
“That,” replied Smith with a wan smile, “was the detonation of two hundred pounds of T.N.T. When you dig down into the underground cave where we used the cold light apparatus, you will find it in fragments. It was my only child, and I’ll take it with me.”
As he finished his head slumped forward on his chest. With an exclamation of dismay Dr. Bird sprang forward and tried to lift the prostrate form.
In an agony of desire the Doctor tightened his grip on the dying man’s shoulder. But Smith collapsed into a heap. Dr. Bird bent forward and tore open his shirt and listened at his chest. Presently he straightened up.
“He is gone,” he said sadly, “and I guess the results of his genius have died with him. He doesn’t strike me as a man who left overmuch to chance. Carnes, is your case completed?”
“Very satisfactorily, Doctor. I have both of the lost packets.”
“All right, then, come back to the wreck and help me pack my burros. I can make my way back to Fallon without a guide.”
“Where are you going, Doctor?”
“That,
