Artana shook his head slowly. "Lord Horta and his savants have made progress in employing the R-ray, drawn from the red stars, as you taught him." He knit his brows. "I have heard of nothing else--but wait. He and his most learned men have worked secretly for many moons, I know not to what purpose. You think--" "We think," cut in Ross grimly, "that it's possible that Lord Horta may be cooking up something new in the ray field." Artana's face darkened. "If that is true," he murmured, "we may have the explanation of the disappearance of two of my brigades. I sent them out in force to scout Horta's territory. No word has come from them." His hand clenched. "A war of rays--here on the Moon!" * * * * * Ross and Moore exchanged uncomfortable glances. They had fought in the terrible war on the Earth when nations battled with the new red ray, and whole fleets of the ancient steel warships were sunk by the first of the ray-torpedoes, before the Council of Seven was formed to rule all Earthly affairs. And they had served in that first Moon-flight, and had slain with rays the first Moon armies who had resisted the intrusion of the Earth-fleet. Was history to repeat itself--in reverse, with Horta's Moon machines raking the Earth with death? Perhaps that strange Purple Death of the Trowbridge message? Ross made his resolve. "If your armies can't find out what Horta's doing, Artana, perhaps my fleet can." "Your fleet?" Artana looked up, a flicker of hope in his somber eyes. "You mean that you would fly over the Caverns?" Ross nodded. "And study the work he has done. Photograph it, and report to you and the Queen. If you then wish us to try to destroy it, I'll take the responsibility. I feel that the Council of Seven would approve." Artana stood up, his eyes alight. "Ah, Ross! If you succeed, and bring peace to the Moon people, your planet and mine will do you homage!" Ross flushed sheepishly. "Well, maybe. For my part I'd rather be overlooked. You know, there's an old, old saying where I come from, 'A hero today, a bum tomorrow.'" "A 'bum'?" echoed Artana, puzzled. "A-a sort of--" Ross remembered in time that there were no beggars on the Moon. Nor panhandlers, nor paupers, nor hobos. "Oh, never mind. We'll take off in the first hour of light, and see what we can see."