Staring directly at them were two Plutonians who had come up from below. The men pushed past, but not before a barking voice had cracked out an order. The Earthmen started to run down, followed by the scrabbling sounds of their pursuers. The barking calls increased in volume. From somewhere a booming sound began, repeated over and over. As the men emerged on the floor below, they heard it repeated on every level. "The alarm's out for us," called Haines, making no effort to keep his voice down. "We've got to run for it!" Laden with the remaining weapons and equipment, the three human beings hurried on, but it soon became clear that four legs were better than two, for the creatures were gaining on them. They had forgotten they were lost. Now they sought only to get out of sight and hide. They dropped their equipment as they ran, down halls, through tunnels, skittering along sloping ramps, heading for what they hoped would prove to be an exit. Behind them an increasing crowd of Plutonians had collected, and several times a spark of electronic power crackled and blazed against the wall over their heads. The pursuers were armed. Burl's lungs began to ache painfully. Close on the heels of his companions he dashed into one room only to find a group of Plutonians coming at him from the other side. His ears were deafened by the barking noises and alarm boomings. He jumped to one side to avoid a Plutonian standing directly in his path, and ran into a narrow tunnel. There was an excited barking as the creatures followed him. With a sinking heart, he realized that he was now alone. Haines and Russ must have been cut off. He gasped for breath. Running in a tight space suit, carrying his oxygen tanks, was hot and hard work. He did not dare drop the tanks, for his only chance was to escape outside. He ran wildly on, hoping to reach an outer door. But he seemed now to be in a maze, for nothing was familiar to him. He could no longer remember how many times he had run into groups of Plutonians, nor could he guess how many followed on his heels. Then he stumbled into a small, round chamber out of which led three tunnels. As he looked around quickly to select his next means of escape, barking Plutonians erupted from each opening. Burl backed up against the wall, knowing that this time he was trapped. A blaze of sparks broke over his head as a blast banged across the room. The red-eyed, scrabbling figures charged, their chinless mouths opening to emit barking calls of bestial anger. One aimed a rodlike contrivance at him, and there was another flare of light. The room dissolved around him in a glare of brilliant green. As he slipped helplessly to the floor, he lost consciousness. Chapter 18. _Sacrifice on the Sacred Moon_