"Here is the bourgeois, Kommandant," said Nat's captor.

Axelson looked at Nat, eye meeting eye in a slow stare. Then he relinquished the controls to the graybeard beside him, and motioned Nat to precede him into the stateroom.

Nat entered. It was an ordinary room, much like that of the captain of the ether-liner now stranded on the Moon. There were a bunk, chairs, a desk and a radio receiver.

Axelson shut the door. He tried to speak and failed to master his emotion. At last he said:

"I am prepared to offer you terms, Nathaniel Lee, in accordance with my promise."

"I'll make no terms with murderers," replied Nat bitterly.

Axelson stood looking at him. His great chest rose and fell. Suddenly he put out one great hand and clapped Nat on the shoulder.

"Wise men," he said, "recognize facts. Within three weeks I shall be the undisputed ruler of Earth. Whether of a desert or of a cowed and submissive subject-population, rests with the Earth men. I have never been on Earth, for I was born on Eros. My mother died at my birth. I have never seen another human woman until to-day."

Nat looked at him, trying to follow what was in Axelson's mind.

"My father fled to Eros, a little planet seventeen miles in diameter, as we have found. He called it a heavenly paradise. It was his intention to found there a colony of those who were in rebellion against the tyrants of Earth.

"His followers journeyed to the Moon and brought back Moon women for wives. But there were no children of these unions. Later there were dissensions and civil war. Three-fourths of the colony died in battle with one another.

"I was a young man. I seized the reins of power. The survivors--these old men--were disillusioned and docile. I made myself absolute. I brought Moon men and women to Eros to serve us as slaves. But in a few years the last of my father's old compatriots will have died, and thus it was I conceived of conquering Earth and having men to obey me. For fifteen years I have been experimenting and constructing apparatus, with which I now have Earth at my mercy.

"But I shall need a.s.sistance, intelligent men who will obey me and aid me in my plans. That is why I saved you and the other officers of your ether-lines. If you will join me, you shall have the highest post on Earth under me, Nathaniel Lee, and those others shall be under you."

Axelson paused, and, loathing the man though he did, Nat was conscious of a feeling of pity for him that he could not control. He saw his lonely life on Eros, surrounded by those phantom humans of the past, and he understood his longing for Earth rule--he the planetary exile, the sole human being of all the planetary system outside Earth, perhaps, except for his dwindling company of aged men.

"To-day, Nathaniel Lee," Axelson went on, "my life was recast in a new mould when I saw the woman you have brought with you. I did not know before that women were beautiful to look on. I did not dream that creatures such as she existed. She must be mine, Nathaniel Lee.

"But that is immaterial. What is your answer to my offer?"

Nat was trying to think, though pa.s.sion distorted the mental images as they arose in his brain. To Axelson it was evidently incomprehensible that there would be any objection to his taking Madge. Nat saw that he must temporize for Madge's sake.

"I'll have to consult my companions," he answered.

"Of course," answered Axelson. "That is reasonable. Tell them that unless they agree to join me it will be necessary for them to die. Do Earth men mind death? We hate it on Eros, and the Moon men hate it, too, though they have a queer legend that something in the shape of an invisible man raises from their ashes. My father told me that that superst.i.tion existed on Earth in his time, too. Go and talk to your companions, Nathaniel Lee."

The Black Caesar's voice was almost friendly. He clapped Nat on the shoulder again, and called the graybeard to conduct him back to his prison.

"Oh, Captain Lee, I'm so glad you're back!" exclaimed Madge. "We've been afraid for you. Is he such a terrible man, this Black Caesar?"

Nat sneered, then grinned malevolently. "Well, he's not exactly the old-fashioned idea of a Sunday-school teacher," he answered. Of course he could not tell the girl about Axelson's proposal.

The little group of prisoners stood on the upper deck of the black ship and watched the Moon men scurrying about the landing-stage as she hovered to her position.

Axelson's father had not erred when he had called the tiny planet, Eros, a heavenly paradise, for no other term could have described it.

They were in an atmosphere so similar to that of Earth that they could breathe with complete freedom, but there seemed to be a lightness and a vigor in their limbs that indicated that the air was supercharged with oxygen or ozone. The presence of this in large amounts was indicated by the intense blueness of the sky, across which fleecy clouds were drifting.

And in that sky what looked like threescore moons were circling with extraordinary swiftness. From thirty to forty full moons, of all sizes, from that of a sun to that of a brilliant planet, and riding black against the blue.

The sun, hardly smaller than when seen from Earth, shone in the zenith, and Earth and Mars hung in the east and north respectively, each like a blood-red sun.

The moons were some of the thousand other asteroids, weaving their lacy patterns in and out among each other. But, stupendous as the sight was, it was toward the terrestrial scene that the party turned their eyes as the black ship settled.

A sea of sapphire blue lapped sands of silver and broke into soft lines of foam. To the water's edge extended a lawn of brightest green, and behind this an arm of the sea extended into what looked like a tropical forest. Most of the trees were palmlike, but towered to immense heights, their foliage swaying in a gentle breeze. There were apparently no elevations, and yet, so small was the little sphere that the ascending curve gave the illusion of distant heights, while the horizon, instead of seeming to rise, lay apparently perfectly flat, producing an extraordinary feeling of insecurity.

Near the water's edge a palatial mansion, built of hewn logs and of a single story, stood in a garden of brilliant flowers. Nearer, beyond the high landing-stage, were the great shipbuilding works, and near them an immense and slightly concave mirror flashed back the light of the sun.

"The death ray!" whispered Brent to Nat.

Axelson came up to the party as the ship settled down. "Welcome to Eros," he said cordially. "My father told me that in some Earth tongue that name meant 'love'."

Never, perhaps, was so strange a feast held as that with which Axelson entertained his guests that day. Dwarfish Moon men pa.s.sed viands and a sort of palm wine in the great banquet-room, which singularly resembled one of those early twentieth century interiors shown in museums. Only the presence of a dozen of the aged guards, armed with ray-rods, lent a grimness to the scene.

Madge sat on Axelson's right, and Nat on his left. The girl's lightheartedness had left her; her face grew strained as Axelson's motives--which Nat had not dared disclose to her--disclosed themselves in his manner.

Once, when he laid his finger for a moment against her white throat, she started, and for a moment it seemed as if the gathering storm must break.

For Nat had talked with his men, and all had agreed that they would not turn traitor, though they intended to temporize as long as possible, in the hope of catching the Black Caesar unawares.

Then slowly a somber twilight began to fall, and Axelson rose.

"Let us walk in the gardens during the reign of Erebos," he said.

"Erebos?" asked Nat.

"The black world that overshadows us each sleeping period," answered Axelson.

Nat knew what he meant. The dark companion of Eros revolves around it every six hours; the day of Eros would therefore never be longer than six hours, this without reckoning the revolution of Eros around the sun. But owing to its small size, it was probable that it was bathed in almost perpetual sunshine.

The sweet scent of the flowers, much stronger than of any flowers on earth, filled the air. They walked across the green lawn and entered a jungle path, with bamboos and creeping plants on either side, and huge palmlike trees. Behind them stalked the guards with their ray-rods.

A lake of deepest black disclosed itself. Suddenly Madge uttered a scream and clung to Nat. "Look, look!" she cried. "It's horrible!"

Suddenly Nat realized that the lake swarmed with monsters. They were of crocodilian form, but twice the size of the largest crocodile, and sprawled over one another in the shallows beside the margin. As the party drew near, an enormous monster began waddling on its clawed feet toward them.

A mouth half the length of the creature opened, disclosing a purplish tongue and hideous fangs. Madge screamed again.