After a long time of breathless running through the passage ways, Alayna finally halted beside a small chamber. Her breath came in gasps. "We can rest here for a moment," she said. "We'll be safe for a little while, I think." She flung herself upon the floor as Roal and Shorty followed her in. Shorty stood guard at the door, but Roal sat down beside her, his eyes tasting the exquisite beauty and tender loveliness of her. * * * * * After a moment she rose to a sitting position, breathing more easily. "I suppose you wonder what this is all about?" she said. "You read my mind on that," said Roal. She took a deep breath. "My real name is Mariana Sebours," she said. "Perhaps you knew of me as a concert singer--" "I looked up your record. Brooks gave me your story. I know that it was your father that I killed back there. I'm sorry, but there was no other way." "Don't worry about _him_," said Mariana. "_They_ killed him long ago only he wasn't actually dead. I'm thankful that the end came for him at last." "Who are _they_?" "The Martians. They are planning to rid the planet of Earthmen and conquer Earth in revenge for what Earth had done to Mars." "But what have we done? I thought everything was serene and peaceful between us!" "No. If you recall, history speaks of the Martians of a century ago as being much different from those around us now. They were not the skinny, dried-out creatures they are now. We have done that to them. Once they were as robust and healthy as we. We have made them what they are and forced them into burrows beneath the desert in order to exist." "But how?" "Merely by being here. My father made a long study of the cause and determined that our two races are simply incompatible. The infinitesimal, almost imperceptible radiations that have long been known to emanate from human beings are nearly lethal to the Martians. They produce the desiccation that we see. "As a result of his work my father was filled with a tremendous sympathy for the Martians and resolved to find a way out of the dilemma. It occupied years of his life, but he found no way. "On the other hand, the Martians themselves found a way to defeat Earth and extract revenge. They discovered _harmeena_. I suppose I don't need to tell you about its effects, but what you know are only the surface effects. You don't understand the long-range results of use of the drug." "What are they? The initial effects are bad enough." "It is in the second generation of addicts that the true results appear. The children of anyone who has used _harmeena_ a single time and obtained the full effect of it will have minds distorted so that they can be made subject to the telepathic controls of the Martians.