He gulped down the rest of his drink and said, "It was a drum; or at least it was a structure that set up a vibration when tapped. As soon as I touched it, a dim rumble filled the room, a vague sound just at the threshold of hearing and all but subsonic. Indeed, as I was able to determine later on, the portion of the sound that was high enough in pitch to be heard was a tiny fraction of the whole. Almost all the sound expressed itself in mighty vibrations far too long-wave to affect the ear, though it shook the body itself. That unheard reverberation gave me the most unpleasantly uneasy feeling you can imagine.

"I had never encountered such a phenomenon before. The energy of my touch had been minute. How could it have been converted into such a mighty vibration? I have never managed to understand that completely. To be sure, there are powerful energy sources underground. There could be a way of tapping the heat of the magma, converting a small portion of it to sound. The initial tap could serve to liberate additional sound energy-a kind of sonic laser, or, if we substitute 'sound' for 'light' in the acronym, we can call it 'saser."

I said, austerely, "I've never heard of such a thing."

"No," said West, with an unpleasant sneer, "I dare say you haven't. It is nothing anyone has heard of. Some combination of geologic arrangements has produced a natural saser. It is something that would not happen, by accident, oftener than once in a million years, perhaps, and even then in only one spot on the planet. It may be the most unusual phenomenon on Earth."

"That's a great deal," I said, "to deduce from one tap of a forefinger."

"As a scientist, sir, I assure you I was not satisfied with a single tap of a forefinger. I proceeded to experiment. I tried harder taps and quickly realized that I could be seriously damaged by the reverberations in the enclosure. I set up a system whereby I could drop pebbles of various sizes on the saser, while I was outside the cave, by means of a makeshift long-distance apparatus. I discovered that the sound could be heard surprising distances outside the cave. Using a simple seismometer, I found that I could get distinct vibrations at distances of several miles. Eventually, I dropped a series of pebbles one after the other, and the effect was cumulative."

I said, "Was that the day when dim rumbles were heard all over the world?"

"Exactly," he said. "You are by no means as mentally deprived as you appear. The whole planet rang like a bell."

"I've heard that particularly strong earthquakes do that."

"Yes, but this saser can produce a vibration more intense than that of any earthquake and can do so at particular wavelengths; at a wavelength, for instance, that can shake apart the contents of cells- the nucleic acids of the chromosomes, for instance."

I considered that, thoughtfully. "That would kill the cell."

"It certainly would. That may be what killed the dinosaurs."

"I've heard it was done by the collision of an asteroid with the Earth."

"Yes, but in order to have that done by ordinary collision, the asteroid postulated must be huge-ten kilometers across. And one must suppose dust in the stratosphere, a three-year winter, and some way of explaining why some species died out and others didn't in a most illogical fashion. Suppose, instead, that it was a much smaller asteroid that struck a saser and that it disrupted cells with its sound vibration. Perhaps ninety percent of the cells in the world would be destroyed in a matter of minutes with no enormous effect on the planetary environment at all. Some species would manage to survive-some would not. It would be entirely a matter of the intimate details of comparative nucleic acid structure."

"And that," I said, with a most unpleasant feeling that this fanatic was serious, "is the weapon the Lord has placed into your hands?"

"Exactly," he said, "I have worked out the exact wavelengths of sound produced by various manners of tapping the saser and I am trying now to determine which wavelength would specifically disrupt human nucleic acids."

"Why human?" I demanded.

"Why not human?" demanded he, in his turn. "What species is crowding the planet, destroying the environment, eradicating other species, filling the biosphere with chemical pollutants? What species will destroy the Earth and render it totally non-viable in a matter of decades, perhaps? Surely not some other than Homo sapiens! If I can find the right sonic wavelength, I can strike my saser in the proper manner, and with the proper force, to bathe the Earth in sonic vibrations that will, in a matter of a day or so, for it takes time for sound to travel, wipe out humanity, while scarcely touching other life-forms with nucleic acids of differing intimate structure."

I said, "You are prepared to destroy billions of human beings?"

"The Lord did it by means of the Flood-"

"Surely you don't believe the Biblical tale of the Flood?"

West said austerely, "I am a creationist geologist, sir."

I understood everything. "Ah," I said. "The Lord promised he would never again send a Flood upon the Earth, but he didn't say anything about sound waves."

"Exactly! The billions of dead will fertilize and fructify the Earth, serve as food for other forms of life who have suffered much at the hands of humanity and who deserve compensation. What's more, a remnant of humanity shall undoubtedly survive. There are bound to be a few human beings who will have nucleic acids of a type that will not be sensitive to the sonic vibrations. That remnant, blessed by the Lord, can begin anew, and will perhaps have learned a lesson as to the evil of Evil, so to speak."

I said, "Why are you telling me all this?" And indeed, it had occurred to me that it was strange that he was doing so.

He leaned toward me and seized me by the lapel of my jacket-a most unpleasant experience, for his breath was rather overpowering-and said, "I have the inner certainty that you can help me in my work."

"I?" I said. "I assure you that I haven't any knowledge whatsoever concerning wavelengths, nucleic acids, and-" But then, bethinking myself rapidly, I said, "Yet come to think of it, I may have just the thing for you." And in a more formal voice, with the stately courtesy so characteristic of me, I said, "Would you do me the honor, sir, of waiting for me for perhaps fifteen minutes?"

"Certainly, sir," he answered, with equal formality. "I will occupy myself with further abstruse mathematical calculations."

As I hastened out of the lounge, I passed a ten-dollar bill to the bartender with a whispered, "See that that gentleman, if I may speak loosely, does not leave until I return. Feed him drinks and put it on my tab, if absolutely necessary."

I never fail to carry with me those simple ingredients I use to call up Azazel and, in a very few minutes, he was sitting on the bed lamp in my room, suffused with his usual tiny pink glow.

He said, censoriously, in his piping little voice, "You interrupted me when I was in the midst of constructing a papparatso with which I fully expected to win the heart of a lovely samini."

"I regret that, Azazel," I said, hoping he would not delay me by describing the nature of the papparatso or the charms of the samini, for neither of which I cared the paring of a fingernail, "but I have here a possible emergency of the most extreme sort."

"You always say that," he said, discontentedly.

Hastily, I outlined the situation, and I must say he grasped it at once. He is very good that way, never requiring long explanations. My own belief is that he peeks at my mind, although he always assures me that he considers my thoughts inviolable. Still, how far can you trust a two-centimeter extraterrestrial who, by his own admission, is constantly trying to overreach lovely saminis, whatever they are, by the most dishonorable ruses? Besides, I'm not sure whether he says he considers my thoughts inviolable or insufferable; but that is neither here nor there.