"Congratulations on your attempt," the message ran, "I have watched your career with the greatest interest, Lee, through the medium of such sc.r.a.ps of information as I have been able to pick up on the Moon. When you are my guest to-morrow I shall hope to be able to offer you a high post in the new World Government that I am planning to establish. I need good men. Fraternally, the Black Caesar."

Nat whirled about. Madge Dawes was standing behind him, trying to read the message over his shoulder.

"Spying, eh?" said Nat bitterly.

"My dear man, isn't that my business?"

"Well, read this, then," said Nat, handing her the message. "You're likely to repent this crazy trick of yours before we get much farther."

And he pointed to the cosmic-ray skiagraph of the Moon on the curved gla.s.s dome overhead. They were approaching the satellite rapidly. It filled the whole dome, the craters great black hollows, the mountains standing out clearly. Beneath the dome were the radium apparatus that emitted the rays by which the satellite was photographed cinematographically, and the gyroscope steering apparatus by which the ship's course was directed.

Suddenly a buzzer sounded a warning. Nat sprang to the tube.

"Gravitational interference X40, gyroscopic aberrancy one minute 29,"

he called. "Discharge static electricity from hull. Mr. Benson, stand by."

"What does that mean?" asked Madge.

"It means I shall be obliged if you'll abstain from speaking to the man at the controls," snapped Nat.

"And what's that?" cried Madge in a shriller voice, pointing upward.

Across the patterned surface of the Moon, shown on the skiagraph, a black, cigar-shaped form was pa.s.sing. It looked like one of the old-fashioned dirigibles, and the speed with which it moved was evident from the fact that it was perceptibly traversing the Moon's surface. Perhaps it was travelling at the rate of fifty thousand miles an hour.

Brent, the chief officer, burst up the companion. His face was livid.

"Black ship approaching us from the Moon, Sir," he stammered.

"Benson's training his guns, but it must be twenty thousands miles away."

"Yes, even our ray-guns won't shoot that distance," answered Nat.

"Tell Benson to keep his guns trained as well as he can, and open fire at five hundred."

Brent disappeared. Madge and Nat were alone on the bridge. Nat was shouting incomprehensible orders down the tube. He stopped and looked up. The shadow of the approaching ship had crossed the Moon's disk and disappeared.

"Well, young lady, I think your goose is cooked," said Nat. "If I'm not mistaken, that ship is Axelson's, and he's on his way to knock us galley-west. And now oblige me by leaving the bridge."

"I think he's a perfectly delightful character, to judge from that message he sent you," answered Madge, "and--"

Brent appeared again. "Triangulation shows ten thousand miles, Sir,"

he informed Nat.

"Take control," said Nat. "Keep on the gyroscopic course, allowing for aberrancy, and make for the Crater of Pytho. I'll take command of the guns." He hurried down the companion, with Madge at his heels.

The gunners stood by the ray-guns, three at each. Benson perched on a revolving stool above the batteries. He was watching a periscopic instrument that connected with the bridge dome by means of a tube, a flat mirror in front of him showing all points of the compa.s.s. At one edge the shadow of the black ship was creeping slowly forward.

"Eight thousand miles, Sir," he told Nat. "One thousand is our extreme range. And it looks as if she's making for our blind spot overhead."

Nat stepped to the speaking-tube. "Try to ram her," he called up to Brent. "We'll open with all guns, pointing forward."

"Very good, Sir," the c.o.c.kney called back.

The black shadow was now nearly in the centre of the mirror. It moved upward, vanished. Suddenly the atomic motors began wheezing again. The wheeze became a whine, a drone.

"We've dropped to two thousand miles an hour, Sir," called Brent.

Nat leaped for the companion. As he reached the top he could hear the teleradio apparatus in the wireless room overhead begin to chatter:

"A-A-A. Don't try to interfere. Am taking you to the Crater of Pytho.

Shall renew my offer there. Any resistance will be fatal. Axelson."

And suddenly the droning of the motors became a whine again, then silence. Nat stared at the instrument-board and uttered a cry.

"What's the matter?" demanded Madge.

Nat swung upon her. "The matter?" he bawled. "He's neutralized our engines by some infernal means of his own, and he's towing us to the Moon!"

The huge sphere of the Moon had long since covered the entire dome.

The huge Crater of Pytho now filled it, a black hollow fifty miles across, into which they were gradually settling. And, as they settled, the pale Earth light, white as that of the Moon on Earth, showed the gaunt ma.s.ses of bare rock, on which nothing grew, and the long stalact.i.tes of gla.s.sy lava that hung from them.

Then out of the depths beneath emerged the shadowy shape of the landing-stage.

"You are about to land," chattered the radio. "Don't try any tricks; they will be useless. Above all, don't try to use your puny ray. You are helpless."

The ship was almost stationary. Little figures could be seen swarming upon the landing-stage, ready to adjust the iron claws to clamp the hull. With a gesture of helplessness, Nat left the bridge and went down to the main deck where, in obedience to his orders, the crew had all a.s.sembled.

"Men, I'm putting it up to you," he said. "Axelson, the Black Caesar, advises us not to attempt to use the Ray-guns. I won't order you to.

I'll leave the decision with you."

"We tried it fifteen minutes ago, Sir," answered Benson. "I told Larrigan to fire off the stern starboard gun to see if it was in working order, and it wasn't!"

At that moment the vessel settled with a slight jar into the clamps.

Once more the teleradio began to scream:

"Open the port hold and file out slowly. Resistance is useless. I should turn my ray upon you and obliterate you immediately. a.s.semble on the landing-stage and wait for me!"

"You'd best obey," Nat told his men. "We've got a pa.s.senger to consider." He glared at Madge as he spoke, and Madge's smile was a little more tremulous than it had been before.

"This is the most thrilling experience of my life, Captain Lee," she said. "And I'll never rest until I've got an X-Ray photograph of Mr.

Axelson's skeleton for the Universal News Syndicate."