The Martian Master! Randall felt his brain reel as he gazed at that mind-shattering thing. The Martian Master--this great head with three bodies! Reason told Randall, even as he strove for sanity, that the thing was but logical, that even on earth biologists had formed multiple-headed creatures by surgery, and that the Martians had done so to combine in one great head, one great brain, the brains of three bodies. Reason told him that the great triple brain inside that bulging head needed the bloodstreams of all three bodies to nourish it, must be a giant intellect indeed, one fitted to be the supreme Martian Master. But reason could not overcome the horror that choked him as he gazed at the awful thing. A hissing voice sounding before him made him aware that the Martian Master was speaking. "You are the Earth-beings with whom we communicated, and whom we instructed to build a matter-transmitter and receiver on earth?" the slow voice asked. "You have come safely to Mars by means of that station?" "We have come safely." Milton's voice was shaken and he could find no other words. "That is well. Long had we desired to have such a station built on earth, since with it there to flash back and forth between the two worlds is easy. You have come, then, to learn of this world and to take back what you learn to your races?" "That is why we came." Milton said, more steadily. "We want to stay only hours on this first visit, and then flash back to earth as we came." * * * * * The head's awful eyes seemed to consider them. "But when do you intend to go back?" its strange voice asked. "Unless the one at your earth station has its receiver operating at the right moment you will simply flash on endlessly as radio waves--will be annihilated." Milton found the courage to smile. "We started from earth at our midnight exactly, and at midnight exactly twenty-four earth hours later, we are to flash back and the receiver will be awaiting us." There was silence when he had said that, a silence that seemed to Randall's strained mind to have become suddenly tense, sinister. The great triple-bodied creature before them considered them again, its eyes moving over them, and when it again spoke the hissing words came very slowly. "Twenty-four earth hours," it said; "and then your receiver on earth will be awaiting you. That time we can measure to the moment, and that is well. For it is not you three Earth-beings who will flash back to earth when that moment comes! It will be Martians, the first of our Martian masses who have waited for ages for that moment and who will begin then our conquest of the earth!