The moon is not only the most prominent object in our heavens, but also an integral part of the earth. We are, so to speak, an astronomical unit, and we affect each other for better or for worse.

We know that the gravitational attraction of the moon causes our tides, and tends to slow up the earth in her daily rotation. It has also been deemed responsible for earthquakes, causing untold suffering among earth's people.

But so far the effect of the moon has been rather an inhuman affair. No man has gone to the moon to see just what conditions are there, and to observe accurately the influence that the moon and earth exercise over each other. But when interplanetary travel does come, when commerce between moon and earth may possibly assume importance in our lives, the influence of the moon upon us may be more accurately determined. And when it is, the amazing series of incidents, pictured in this story, may yet come true.

Professor Erickson, head of the International Seismographical Institute, sat with bowed head and pale face, watching the stylus of the instrument before him trace its path on the slowly revolving drum. The laboratory, situated high in the Himalayas, trembled slightly as mid-winter storms roared and whistled around it, but something quite different, and infinitely more sinister, was causing the needle to wander from its ordinarily straight path.

Suddenly, with horrible certainty, it jumped, wavered back and forth, and then moved rapidly to the right, until its black ink no longer traced a line on the white paper.

"Holden," shouted Erickson to his assistant, "what does the direction and distance finder tell us? The stylus has run clear off the graph."

Young Jack Holden was working feverishly over the dials and levers of the panel before him. Slender yet strong, he looked like a long-bow of stout old yew as he bent to the task. His steel gray eyes focused intently on the verniers, taking the readings. The muscles in his tanned cheeks were tight as he turned toward his superior. For a moment the very storm seemed to hush, awaiting the words. Then he spoke.

"It's the Laurentian fault!"

For a moment both men stared at each other, stunned and helpless.

"That means," Holden managed to say, "that New York is a mass of ruins."

Pictures were forming in his mind; he saw the huge steel and glass towers of the city, tossed and torn by the convulsive writhings of the earth beneath. Great engineers had said that the city was safe, that no tremors would ever disturb it, but they knew nothing of the terrific force of such a shock as this. Those massive buildings, thousands of feet high, would now be mere heaps of twisted junk. Holden closed his eyes to shut out the picture, but to no avail. His sister! God! She was probably one of the millions who now lay, crushed, bleeding and helpless beneath the wreckage of the too-proud metropolis.

"My boy," the professor was speaking, "we must stay with our work, no matter what happens." His voice was low; his entire family had been wiped out, without doubt, but Science must be served.

For hours the two sat before their instruments, as shock after shock was recorded. Jones came down from the television room above, and his report confirmed their observations in horrible detail.

"All communications from the city itself are cut off, but an airliner from England, which was about to dock, has broadcast the scene. Aid is being rushed from all over the world, but at a conservative estimate ten million are already dead, and millions more will probably die, buried and hidden as they are beneath the wreckage."

At last, nearly five hours after the first shock, the Professor stood up.

"I think that is all. My prophecies have come true, and at last my theories will be needed. But the cost of it all, the horrible cost!"

Two weeks later a group of men were seated around the conference table in the spacious offices of the Department of Public Safety of the World Union. All faces were turned toward the stooped figure of Professor Erickson, who was speaking from the head of the table.

"Gentlemen, I have outlined to you, only too briefly, the damage caused by the quake a few days ago. I now state that a repetition of such a disaster is imminent. Great faults have formed in the basic granites throughout the entire globe. Observations recorded during five centuries since the first conception of the idea by Dr. Maxwell Allen in 1931, show conclusively that Earth-tides, set up by the attraction of the moon, cause a sweeping series of stresses and strains. These, coming to a fault, produce earthquakes. Now that there are huge faults in the basic rock, these quakes will be of a tremendous force and range which the most modern structures will be unable to resist."

"Professor," spoke John Dorman, Secretary of Public Safety, "if all this is true, and we are assured that it is, what on earth can be done about it?"

"Gentlemen, during nearly seventy years I have studied that problem, and I have come to only one conclusion. Nothing on earth can be done about it, if you permit the remark, but men from earth can do something. Destroy the moon!"

A gasp went up from the great men assembled there. Erickson's colleagues nodded in helpless agreement.

"But how?" The question came from all sides. Famous engineers looked at each other questioningly.

"Gentlemen." This was a new voice, young and full of energy.

"Mr. Holden," responded the chairman.

"Professor Erickson was so kind as to confide in me several years ago, and since then I have been at work on this problem. I have solved it."

Eager interest shone on all faces. Jack Holden was known and liked by many of these men, despite his youth. His discovery of hexoxen, the chemical which turned solid matter into almost intangible vapor, had created quite a stir in scientific circles.

He now continued his address.

"If all the resources of Earth are made use of, it would be possible to produce hundreds of tons of hexoxen and sufficient amounts of the element Europium to act as a catalyst. That would be plenty to reduce the moon to a gaseous state. The clouds of gas could then be penetrated by anti-gravitational screens, which would cause the smaller pieces to drift off into space, where they will do no harm whatsoever."

Several distinguished engineers nodded their heads. One of them spoke.

"Mr. Secretary, the plan is entirely feasible. I move that Mr. Holden be given permission to make use of all the necessary resources to carry out his plan, and that he be placed in sole charge, assisted by an advisory board of which Professor Erickson shall be chairman."

The motion was carried, the papers drawn up, and the meeting adjourned.

Holden grasped Professor Erickson firmly by the arm and hurried him to the elevator.

"We've got just five minutes to get to the port. We're catching the first airliner for San Francisco. There are three of the latest model Mars-Earth freighters there, which we will use for our expedition. We will also be near the best source of Europium. Hurry."

As the elevator shot downward, the old professor endeavored to congratulate Holden on his appointment.

"Forget it. This was your idea, and they should have named you leader of the expedition, but that really doesn't make much difference. Anything you say goes, see?"

A crowd was milling around the entrance to the Western Hemisphere tunnel. An official tried to stop Holden and his companion as they pushed their way through the crowd.

"The liner is leaving. You can't go in there."

"Oh, we can't, huh? Here."

A single glance at the paper shoved under his nose, and the gatekeeper came to life.

"Right this way, you're just in time."

The three ran out on top of the building, where the beautiful silver shape of the liner floated at the top of a short tower. An officer was just giving the command to cast loose, but as Holden shouted to him, he countermanded it, for special orders from the Union had to be obeyed, even if schedules were spoiled.

Nodding their thanks to the now obsequious gateman, the two scientists hurried up the ladder that had been dropped for them; again came the shouted "Cast off," and the huge liner, impelled by powerful motors, rose rapidly to the high altitude at which she traveled.

"Message for you, sir," said a pleasant voice at Holden's elbow, and he turned. A neatly uniformed boy held out to him a thin envelope. Breaking the seal, he read rapidly.

"Will you show us in to the Captain, please," he addressed the boy as he finished the message.

The lad nodded, and led them down a long hall to the bow of the ship and up to the bridge.

"Mr. Holden, I presume? And Professor Erickson? I am Captain Linet."

The Captain was an immense man, well over six feet, with the build of a prizefighter. His face was pleasant, but there was an expression of intense sorrow in his deep blue eyes.

"I understand that you have been appointed to head an expedition to the moon, the nature of which has not been revealed, but which will do away forever with the earthquakes which have become so prevalent. I wish to join that expedition. My beloved wife was in New York at the time of the last quake. You understand."

Holden nodded sympathetically. He would be glad to have all the men like this he could find, and he expressed that opinion to the Captain.

"Thank you. I will resign my position when we reach San Francisco, and will await your orders."

"But, Captain," Holden asked, "how did you know that I was head of the expedition?"

"Oh, the news has been broadcast everywhere, with instructions to give you any aid possible. But no information was given as to the exact nature of the trip. Could I be trusted—?"

"Why certainly. We are going to destroy the moon, wipe it out of existence, so that it will cease to exert the tremendous gravitational pull that has been causing—."

At that moment a petty officer appeared behind the Captain.

"Have you any further orders concerning the cargo to be dumped at New Orleans?"

"No. I thought I gave you to understand that there were to be no more additions to that cargo. Didn't you hear me?"

"I beg your pardon, sir," the man said, and walked away.

"I wonder how much of our conversation he heard?" mused Erickson. "But then, I suppose it makes no difference."

After a few minutes of conversation, Holden asked the Captain if they could be shown their cabins, so that they could get a few hours of rest before reaching their destination. The request was readily granted, and in a few minutes Holden was alone in a neat little room, furnished with a comfortable chair, tables along two walls, and a very pleasant looking berth built into the third side. The professor had a similar place a few doors down the hall.

Holden threw off his shoes and coat and tumbled into the berth. The events of the last weeks were spinning in his head, and a procession of visions passed before his eyes. That terrible catastrophe, the trip to Europe, to the capitol of the World Union, and now, the appointment as leader of the most important expedition in the history of the universe, with the possible exception of that first epoch-making voyage to Mars back in 2350.

Another vision appeared before his eyes. Jean! Jean, his own sweetheart, the one person in the world who mattered, gone now for a full year. Why had she decided to make the voyage to Mars? What could have happened to the ill-fated Gloriana, with her hundreds of passengers and valuable cargo? A year ago she had left; and, as some people said, merely drifted out into space, never to be heard from again.

A deep sob shook Holden's body as he thought of that beautiful girl, who, laughing at his fears, had stepped into the space flyer with a smile on her lips, promising to come back in a year and marry him.

At last, however, these memories gave way before exhaustion, and he fell into a sleep, troubled by strange dreams. It seemed that a great serpent had attacked him, and, flinging its coils about his body, was slowly squeezing out his life. Suddenly, he was wide awake. Strong hands were on his throat, the thumbs were pressed tight against his larynx.

He struggled to gain his breath, to shout for help, but the pressure closed his throat. In another moment it would be too late. Then his mind cleared; raising both hands to the back of his neck, he grasped the little fingers of his assailant, and pulled with all his strength. The man gave a cry of pain and anger and relaxed his grip. Holden gulped in a breath of air, and flung himself from his berth, endeavoring to catch and hold the coward who had attacked in the dark. The man, however, was wiry and quick. With a sudden jerk he wriggled loose, gained the door and was gone. When Holden reached the corridor, no one was in sight. Quickly he walked to Professor Erickson's room, awakened him, and told him what had happened.

Erickson rang up a steward, who promised to do everything in his power to apprehend the culprit.

"Who could it have been?" asked Erickson.

"I haven't the slightest idea. I have no enemies that I know of. I'm not carrying any valuables. It was probably a case of mistaken identity."

The incident was dismissed with that interpretation, and it was several weeks before Holden thought of it again, but then he wished fervently that he had investigated more thoroughly.