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. "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 mass 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.