and Erickson picked many from among the scientific men of their acquaintance, all experts in their lines. The Interplanetary Transportation Company recommended several of their best men for the positions on board requiring technical knowledge of the handling of space ships, and Captain Linet also picked up a few of his friends—brave, strong men. There were to be fifty on each ship.

The start had been scheduled for the fifteenth of the month, but on the tenth Professor Erickson received a radiogram from the Seismographical Institute which read as follows: "Observations indicate a series of stresses approaching Pacific fault, probably aggravated by unusual tidal action of moon in that area tenth of next month."

"Gentlemen," the old professor addressed the little group gathered in the office allotted them in the I. T. C. building, "as you know, this is the tenth. Without allowing for possible delays, we would just have time, starting tomorrow, to reach the moon, distribute the hexoxen and Europium and get out of range by the first. That would leave us only ten days for cutting the gaseous mass into small pieces which will drift harmlessly into space. If we do not have that task accomplished by the time indicated in this message, Los Angeles, San Francisco, Portland and Seattle will suffer the fate which overtook New York such a short time ago."

Holden's face was pale as he rose and nodded to the professor. "If Captain Linet will take the responsibility of getting the crews on board, I will see that we are ready to leave at high noon tomorrow."

The meeting adjourned in a flurry of papers, a ringing of bells, and brisk words spoken into television transmitters.

All that night and all the next morning work went on. At eleven A. M. the last five hundred tons of hexoxen was loaded on the San Francisco, which was to be the flagship; at noon exactly the huge doors swung shut, the repulsion tubes at the stern began to glow, and the beautiful cigar-shaped ship rose from the earth, followed immediately by the Los Angeles and the Ganymede. They cruised slowly, at about six hundred miles per hour, until they were well out of the earth's atmosphere, when full power was slowly turned on, and the trip to the moon was actually begun.

Holden and Erickson stood in the bow of the San Francisco, watching the skilful hands of the pilot, Edwards, as he spun the dials controlling the steering discharges, keeping the delicate needle in the direction indicator exactly in line with the path indicated on the chart before him.

"How are things going, Edwards?" Holden asked.

"Fine so far. We have developed our necessary velocity in very good time. If you would allow me a word of advice, I would suggest that you turn in now, as the tremendous acceleration of the last few minutes, and the speed with which we are now traveling, are liable to affect you disagreeably, since this is your first trip. Our course has been plotted by the experts of the I. T. C., and there is nothing to do now but to stay on it."

Holden decided that the suggestion was a good one, as he was beginning to feel light-headed and slightly bewildered. Erickson, however, chose to go down to the observation room, for a glance at the earth, and the two parted company in the hall which led through the storage compartments, located amidships.

As Holden continued on down the hall toward his cabin, a sudden feeling of danger came over him. Memories of the clutching hands that had endeavored to throttle the life out of him shot into his mind. He laughed to himself, attributing the fear to the mental disorganization suffered by travelers on their first trip into space. He opened the door of his cabin, and stepped inside, instinctively reaching for the light-switch.

His hand encountered warm flesh! Swiftly he went into action, diving for the stranger's throat, but his unknown antagonist had the advantage of being prepared. Holden heard a soft swish, a tremendous weight seemed to descend on him, crushing his entire body. Buzzing lights flashed before his eyes. Then came darkness, and he sank, unconscious, to the floor.

"Jack, Jack, my boy." The voice came from a great distance, slowly penetrating the great cloud which hung over him. "Jack, what's the matter with you?" He realized that someone was talking to him. With a mighty effort, he opened his eyes and endeavored to distinguish the speaker among the thousands of objects which whirled before his eyes. At last things settled down, and he saw the anxious faces of Erickson and Captain Linet bending above him.

"Somebody was in my cabin, and slugged me over the head with a black-jack when I came in. Look at the wall-cabinet, will you, professor, and see if any of the papers are missing?"

The professor stepped over to one side of the room, and bent to examine the compartment set in the solid metal of the wall.

"Holden," he cried, "the intruder tried to open the cabinet, but was unable to do so, or else you came back sooner than he had expected. There are tool marks all around the lock."

"That means," exclaimed Captain Linet, "that the man either has tools in his cabin, or has access to the machine shop here on board."

Scarcely had he spoken when the floor leaped beneath their feet, a deafening roar sounded from the bow, and the lights went out. Sounds of running feet came from the corridor. The three men picked themselves up from the positions into which they had been thrown by the force of the shock, and rushed to the door.

The emergency lights had been switched on, and they could see fairly well by the dim illumination. They hurried into the pilot house at the bow. Edwards was struggling with the controls, pale but determined.

"There's something wrong with the steering apparatus we've run into a group of tiny meteorites, but, thank God, they didn't hit hard enough to penetrate the shell. The other ships seem to be in good shape; they're standing by a few hundred miles away, for I've signaled them not to get themselves tangled up with this shower."

At that moment a breathless tube-man came running in.

"Report for you, sir, from the tube-room. Someone tampered with the timing device that controls the feeding of the charges. We can have it repaired in a few hours."

"Good," snapped Edwards. "Give me all the power you can from the emergency tubes, and keep the main stern tubes going full." Turning to Holden, he continued, "I'll try to steer out of this shower by means of the deceleration tubes, but I don't dare use up too much of their power, and they can't be recharged until after we land."

"Captain Linet," Holden ordered, "start a search of the ship. Go over every man's room first, and pay especial attention to their baggage. Read all the private papers you can find, and see if you can't get some clue as to why all this is being done. By the way, do we have any arms on board?"

Linet smiled. "While your orders didn't cover that matter, sir, I took the liberty to bring with me a very complete arsenal of small arms, and three of the newly developed rapid-fire disintegrators, using your hexoxen as the material for the bullets. Very effective, I may add."

"Fine. As soon as a man is searched, and has been entirely cleared of all shadow of suspicion, arm him."

Erickson departed with Captain Linet, and Holden remained in the pilot room, helping Edwards work the ship onward. After about an hour and a half, they had reached an area free from meteorites of dangerous size.

"I think I can handle her myself, now. Thanks very much," Edwards said, and Holden departed to do a little investigating on his own.

In the tube-room at the stern, he found Linet. The doughty Captain had evidently been giving the men a thorough raking over, for they were all looking slightly sheepish, as men do when they have had to reveal the most intimate details of their lives.

"All in shape here," Linet reported. "Five of