* * * * * Dex shuddered; and a low moan came from Greca, whose clear blue eyes had rested on the contents of this vast room before in her capacity as hostage and interpreter for the inhuman Rogans. And now another sense of Dex's began to register perception on his brain. A peculiar odor came to his nostrils. It was a musky, fetid odor, like that to be smelled in an animal cage; but it was sharper, more acrid than anything he had ever smelled on Earth. It smelled--ah, he had it!--_reptilian_. As though somewhere nearby a dozen titanic serpents were coiled ready to spring! Looking about, Dex saw a six-foot square door of bars in one wall of the laboratory--like the barred entrance to a prison cell. It was from the interstices of this door that the odor seemed to emanate; but he had no chance to make sure, for now the Rogan leader approached him. "I will first show you," he said, through his mouthpiece, Greca, "what happens to those who oppose our orders. We have a slave who tried to run away into the surrounding jungles three suns ago...." A man was dragged into the chamber. He was slightly taller and more stockily muscled than an Earthman might be; but otherwise, in facial conformation and general appearance, he might have come here straight from New York City. Dex felt a great pang of sympathy for him. He was so plainly one of humankind, despite the fact that he had been born on a sphere four hundred million miles from Dex's. The fellow was paralyzed with horror. His eyes, wide and glazed, darted about the torture room like those of a trapped animal. And yet he made no move to break away from the clutch of the two Rogans who held him. He knew he was helpless, that wild-eyed glance told Dex. Knew it so thoroughly that not even his wildest terror could inspire him to try to make a break for freedom, or strike back at the implacable Rogan will. * * * * * At a nod from the leader, the man was stripped to the waist. Here Dex started in amazement. The man's broad chest was seamed and crisscrossed by literally hundreds of tiny lateral scars, some long healed, and some fresh incisions. He was dragged to a metal plate set upright in the wall, and secured to it by straps of metal. Evidently the miserable being knew what this portended, for he began to scream--a monotonous, high-pitched shriek that didn't stop till he was out of breath. The Rogan leader stared at him icily, then depressed a small lever set in the wall beside him. The plate against which the captive was bound began to shine softly with a blue light. The slave twisted in his bonds, screaming again. Rhythmic shudders jerked at his limbs. His lips turned greenish white. The shudders grew more pronounced till it seemed as though he were afflicted with a sort of horrible St. Vitus dance. Then the tall Rogan pulled back the lever. The slave hung away from his supporting shackles, limp and unconscious.