"Or—well, trouble in the sky?"
Artana shook his head, puzzled.
Ross answered his unspoken question. "One of our ships was destroyed on our flight from the Earth. And I don't think it was an accident."
"A rocket ship?" Artana sat up. Then his eyes flashed. "Horta?" he murmured, as if asking himself a question.
Moore leaned forward. "Has Horta been up to anything in the ray business?" he asked eagerly.
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?