The enormous room was illuminated by globular overhead lamps which cast stationary shadows on its glass-smooth floor and turned the walls into light-mirroring surfaces which deflected the radiance without diminishing it. The man who resembled Summers spoke calmly, but there was a slight tremor in his voice. "We will have to wait. We must force ourselves to be patient. It would be easier to let ourselves go, to act impulsively. Inaction is difficult when you feel you're at the mercy of something dangerous which you know nothing about. But we can't afford to take unnecessary risks. We still have one safeguard. Being armed may not protect us, but it's an advantage we can't afford to toss away. We'll be tossing it away if we lose our heads." It seemed only natural to the man that he should be armed. The weapon he was clasping surprised him no more than his familiar attire had done. Its presence in his hand he took for granted, and its absence would have bewildered him and greatly increased his apprehension. The woman was also clasping a weapon, and taking her possession of it so much for granted that she did not even glance down at it when the man stressed the fact that they were both armed by tapping her lightly on the wrist. The two small, compact energy weapons glittered in the downstreaming radiance. Outwardly they were exact replicas of nuclear hand-guns, accurate in range and deadly when fired. Nuclear hand-guns were capable of disintegrating any object in their path, living or inanimate, within a radius of thirty-five feet. There was no nuclear fallout, no diffusion of destructive radioactivity, no risk to the user at all. Seventy years of controlled atomic research on the red planet made such weapons available to everyone privileged to carry them: regional law-enforcement coordinators, authorized destroyers of dangerous animal pests and explorers in space. But the weapons which the man and the woman were clasping had not been atomically powered. They were infinitely less destructive, with barely enough fire-power to kill a man or large animal at close range, or bring down a bird in flight. But the man and the woman did not know that. They had no way of knowing. The woman was the first to notice the change in the large, cagelike object. The light shifted, and a slow shadow crept across it, elongating as it moved, first parallel with the box and then at right angles to it. The shadow was sinuous and very dark, and it made a rasping sound on the glass-smooth floor as it advanced in a swift glide. A yard from the cage it ceased to be a shadow. The woman went rigid. Her hand darted to her throat and all of the color drained out of her face. She stared wordlessly, unable to move or speak, and her stunned helplessness almost led to the man's undoing. He was half turned toward her and did not see the long-fanged, catlike beast until it was within eight feet of him.