"Ah, so fear exists on Earth, too?" asked Axelson blandly. "That makes my conquest sure. I suspected it, and yet I was not sure that science had not conquered it. But there is no cause for fear. A magnetic field protects us. See!"

For the waddling monster suddenly stopped short as if brought up sharply by the bars of a cage, and drew back.

Axelson turned and wheezed in the Moon language--if the gibbering of the dwarfs could be called speech--and one of the guards answered him.

"These primitive dwellers on Eros I have preserved," said Axelson, "as a means of discipline. The Moon animals are afraid of them. I keep a supply of those who have transgressed my laws to feed them. See!"

He turned and pointed. Two guards were bringing a gibbering, screeching, struggling Moon man with them. Despite his strength, he seemed incapable of making any resistance, but his whole body quivered, and his hideous face was contorted with agony of terror.

At a distance of some fifty feet they turned aside into a little bypath through the jungle, reappearing close beside the Lake upon a raised platform. And what happened next happened so swiftly that Nat was unable to do anything to prevent it.

The guards disappeared; the Moon man, as if propelled by some invisible force, moved forward jerkily to the lake's edge. Instantly one of the saurians had seized him in its jaws, and another had wrenched half the body away, and the whole fighting, squirming ma.s.s vanished in the depths.

And from far away came the screeching chant of the Moon men, as if in invocation to some hideous deity.

And, moving perceptibly, the huge black orb of Eros's dark satellite crept over the sky, completely covering it.

Axelson stepped forward to where Nat stood, supporting Madge in his arms. The girl had fainted with horror at the scene.

"Your answer Nathaniel Lee," he said softly. "I know you have been postponing the decision. Now I will take the girl, and you shall give me your answer. Will you and these men join me, or will you die as the Moon man died?" He spoke wheezily, as if he, like Nat, had a cold.

And he put his arm around Madge.

Next moment something happened to him that had never happened in his life before. The Black Caesar went down under a well-directed blow to the jaw.

He leaped to his feet trembling with fury and barked a command.

Instantly the old guards had hurled themselves forward. And behind them a horde of Moon men came, ambling.

While the guards covered their prisoners with their ray-rods, two Moon men seized each of them, imprisoning him in their unbreakable grasp.

Axelson pointed upward. "When the reign of Erebos is past," he said, "you become food for the denizens of the lake, unless you have agreed to serve me."

And he raised Madge in his arms, laughing as the girl fought and struggled to resist him.

"Madge!" cried Nat, trying to run toward her.

So furious were his struggles that for a moment he succeeded in throwing off the Moon men's grasp. Then he was caught again, and, fighting desperately, was borne off by the dwarfs through the shadows.

They traversed the border of the lake until a small stone building disclosed itself. Nat and the others were thrust inside into pitch darkness. The door clanged; in vain they hurled themselves against it.

It was of wood, but it was as solid as the stone itself, and it did not give an inch for all their struggles.

"Where is your Kommandant?" The whisper seemed in the stone hut itself. "Your Nathaniel Lee. I must speak to him. I am the guard who brought him to the Black Caesar on board the ship."

"I'm here," said Nat. "Where are you?"

"I am in the house of the ray. I am on guard there. I am speaking into the telephone which runs only to where you are. You can speak anywhere in the hut, and I shall hear you."

"Well, what do you want?" asked Nat.

"You love the Earth woman. I remember, when I was a boy, we used to love. I had forgotten. There was a girl in Stamford.... Tell me, is it true that this is the year 2044 and that the proletariat has not yet triumphed?"

"It's true," said Nat. "Those dreams are finished, We're proud of the World Federation. Tell me about Madge Dawes--the Earth woman. Is she safe?"

"He has taken her to his house. I do not think she is harmed. He is ill. He is closely guarded. There are rumors afoot. I do not know."

"What do you want, then?"

"If the Black Caesar dies will you take me back to Earth again? I long so for the old Earth life. I will be your slave, if only I can set foot on Earth before I die."

"Can you rescue us?" Nat held his breath.

"The Moon men are on guard."

"They have no ray-guns and you have."

"The penalty would be terrible. I should be thrown to the monsters."

"Can you get us each a ray-gun? Will you risk it, to get back to Earth?" asked Nat.

A pause. Then, "My friend, I am coming."

Nat heard Benson hissing in his ear, "If we can surprise them, we can get possession of the black ship and return."

"We must get Madge Dawes."

"And smash the mirror," put in Brent.

After that there was nothing to do but wait.

The door clicked open. An indistinct form stood in the entrance. It was already growing light; the dark satellite that eclipsed Eros was pa.s.sing.

"Hush! I have brought you ray-rods!" It was the old man with whom Nat had spoken on the boat. Under his arm he held five metallic rods, tipped with luminous gla.s.s. He handed one to each of the prisoners.

"Do you know how to use them?" he asked.

Nat examined his. "It's an old-style rod that was used on earth fifty years ago," he told his men. "I've seen them in museums. It came into use in the Second World War of 1950 or thereabouts. You slip back the safety catch and press this b.u.t.ton, taking aim as one did with the pistol. You fellows have seen pistols?"

"My father had an old one," said the chief mate, Barnes.

"How many times can they be fired without reloading?" Nat asked the old guard.

"Ten times; sometimes more; and they were all freshly loaded yesterday."