"Axelson speaking. At the next full moon all the American Province of the World Federation will be annihilated, as the Chinese Province was at the last. There's no hope for you, good people. Send out your vacuum liners. I can use a few more of them. Within six months your world will be depopulated, unless you flash me the signal of surrender."

Would the proud old Earth have to come to that? Daily those ominous threats had been repeated, until popular fears had become frenzy. And Nat was being sent out as a last hope. If he failed, there would be nothing but surrender to this man, armed with a super-force that enabled him to lay waste the Earth from the Moon.

Within one hour, those invisible, death-dealing rays had destroyed everything that inhaled oxygen and exhaled carbon. The ray with which the liner was equipped was a mere toy in comparison. It would kill at no more than 500 miles, and its action was quite different.

As a prelude to Earth's surrender, Axelson demanded that World President Stark and a score of other dignitaries should depart for the Moon as hostages. Every ray fortress in the world was to be dismantled, every treasury was to send its gold to be piled up in a great pyramid on the New York landing-stage. The Earth was to acknowledge Axelson as its supreme master.

The iron claws were turning with a screwlike motion, extending themselves, and slowly raising the interplanetary vessel until she looked like a great metal fish with metal legs ending with suckerlike disks. But already she was floating free as the softly purring engines held her in equipoise. Nat climbed the short ladder that led to her deck. Brent came up to him again.

"That teleradio message from Axelson--" he began.

"Yes?" Nat snapped out.

"I don't believe it came from the Moon at all."

"You don't? You think it's somebody playing a hoax on Earth? You think that wiping out of China was just an Earth-joke?"

"No, Sir." Brent stood steady under his superior's sarcasm. "But I was chief teleradio operator at Greenwich before being promoted to the Province of America. And what they don't know at Greenwich they don't know anywhere."

Brent spoke with that self-a.s.surance of the born c.o.c.kney that even the centuries had failed to remove, though they had removed the c.o.c.kney accent.

"Well, Brent?"

"I was with the chief electrician in the receiving station when Axelson was radioing last week. And I noticed that the waves of sound were under a slight Doppler effect. With the immense magnification necessary for transmitting from the Moon, such deflection might be construed as a mere fan-like extension. But there was ten times the magnification one would expect from the Moon; and I calculated that those sound-waves were shifted somewhere."

"Then what's your theory, Brent?"

"Those sounds come from another planet. Somewhere on the Moon there's an intercepting and re-transmitting plant. Axelson is deflecting his rays to give the impression that he's on the Moon, and to lure our ships there."

"What do you advise?" asked Nat.

"I don't know, Sir."

"Neither do I. Set your course Moonward, and tell Mr. Benson to keep his eyes peeled."

The Moon Colony, discovered in 1976, when Kramer, of Baltimore, first proved the practicability of mixing neon with the inert new gas, leucon, and so conquering gravitation, had proved to be just what it had been suspected of being--a desiccated, airless desolation.

Nevertheless, within the depths of the craters a certain amount of the Moon's ancient atmosphere still lingered, sufficient to sustain life for the queer troglodytes, with enormous lung-boxes, who survived there, browsing like beasts upon the stunted, aloe-like vegetation.

Half man, half ape, and very much unlike either, these vestiges of a species on a ruined globe had proved tractable and amenable to discipline. They had become the laborers of the convict settlement that had sprung up on the Moon.

Thither all those who had opposed the establishment of the World Federation, together with all persons convicted for the fourth time of a felony, had been transported, to superintend the efforts of these dumb, unhuman Moon dwellers. For it had been discovered that the Moon craters were extraordinarily rich in gold, and gold was still the medium of exchange on Earth.

To supplement the vestigial atmosphere, huge stations had been set up, which extracted the oxygen from the subterranean waters five miles below the Moon's crust, and recombined it with the nitrogen with which the surface layer was impregnated, thus creating an atmosphere which was pumped to the workers.

Then a curious discovery had been made. It was impossible for human beings to exist without the addition of those elements existing in the air in minute quant.i.ties--neon, krypton, and argon. And the ships that brought the gold bars back from the Moon had conveyed these gaseous elements there.

The droning of the sixteen atomic motors grew louder, and mingled with the hum of gyroscopes. The ladder was drawn up and the port hole sealed. On the enclosed bridge Nat threw the switch of durobronze that released the non-conducting shutter which gave play to the sixteen great magnets. Swiftly the great ship shot forward into the air. The droning of the motors became a shrill whine, and then, growing too shrill for human ears to follow it, gave place to silence.

Nat set the speed lever to five hundred miles an hour, the utmost that had been found possible in pa.s.sing through the earth's atmosphere, owing to the resistance, which tended to heat the vessel and damage the delicate atomic engines. As soon as the ether was reached, the speed would be increased to ten or twelve thousand. That meant a twenty-two hour run to the Moon Colony--about the time usually taken.

He pressed a lever, which set bells ringing in all parts of the ship.

By means of a complicated mechanism, the air was exhausted from each compartment in turn, and then replaced, and as the bells rang, the men at work trooped out of these compartments consecutively. This had been originated for the purpose of destroying any life dangerous to man that might unwittingly have been imported from the Moon, but on one occasion it had resulted in the discovery of a stowaway.

Then Nat descended the bridge to the upper deck. Here, on a platform, were the two batteries of three ray-guns apiece, mounted on swivels, and firing in any direction on the port and starboard sides respectively. The guns were enclosed in a thin sheath of osmium, through which the lethal rays penetrated unchanged; about them, thick shields of lead protected the gunners.

He talked with Benson for a while. "Don't let Axelson get the jump on you," he said. "Be on the alert every moment." The gunners, keen-looking men, graduates from the Annapolis gunnery school, grinned and nodded. They were proud of their trade and its traditions; Nat felt that the vessel was safe in their hands.

The chief mate appeared at the head of the companion, accompanied by a girl. "Stowaway, Sir," he reported laconically. "She tumbled out of the repair shop annex when we let out the air!"

Nat stared at her in consternation, and the girl stared back at him.

She was a very pretty girl, hardly more than twenty-two or three, attired in a businesslike costume consisting of a leather jacket, knickers, and the black spiral puttees that had come into style in the past decade. She came forward unabashed.

"Well, who are you?" snapped Nat.

"Madge Dawes, of the Universal News Syndicate," she answered, laughing.

"The devil!" muttered Nat. "You people think you run the World Federation since you got President Stark elected."

"We certainly do," replied the girl, still laughing.

"Well, you don't run this ship," said Nat. "How would you like a long parachute drop back to Earth?"

"Don't be foolish, my dear man," said Madge. "Don't you know you'll get wrinkles if you scowl like that? Smile! Ah, that's better. Now, honestly, Cap we just had to get the jump on everybody else in interviewing Axelson. It means such a lot to me."

Pouts succeeded smiles. "You're not going to be cross about it, are you?" she pleaded.

"Do you realize the risk you're running, young woman?" Nat demanded.

"Are you aware that our chances of ever getting back to Earth are smaller than you ought to have dreamed of taking?"

"Oh, that's all right," the girl responded. "And now that we're friends again, would you mind asking the steward to get me something to eat? I've been cooped up in that room downstairs for fifteen hours, and I'm simply starving."

Nat shrugged his shoulders hopelessly. He turned to the chief mate.

"Take Miss Dawes down to the saloon and see that w.a.n.g Ling supplies her with a good meal," he ordered. "And put her in the Admiral's cabin. That good enough for you?" he asked satirically.

"Oh that'll be fine," answered the girl enthusiastically. "And I shall rely on you to keep me posted about everything that's going on. And a little later I'm going to take X-ray photographs of you and all these men." She smiled at the grinning gunners. "That's the new fad, you know, and we're going to offer prizes for the best developed skeletons in the American Province, and pick a King and Queen of Beauty!"

"A radio, Sir!"

Nat, who had s.n.a.t.c.hed a brief interval of sleep, started up as the man on duty handed him the message. The vessel had been constantly in communication with Earth during her voyage, now nearing completion, but the dreaded A-A-A that prefaced this message told Nat that it came from Axelson.