He broke into a dead run. It might have seemed ironic that he should rush to help Sandy's sister in whatever disaster had befallen her when they were facing the end of the whole solar system. In cold blood, it couldn't be considered to matter. But Burke ran. He panted when he plunged down the ramp to the lower portions of the asteroid. He reached the huge cavern in which the motionless power-generator towered storeys high toward a light-laced ceiling. "Holmes!" he shouted, and ran on. "Holmes!" He'd been no farther than this, before, but he went on into tunnels with only double lines of light-tubes overhead, and he shouted and heard his own voice reverberating in a manner which seemed pure mockery. But as he ran he continued to shout. And presently Holmes shouted in return. There was a process of untangling innumerable echoes, and ultimately they met. Holmes was deathly white. He carried something unbelievable in his hands. "Here!" he growled. "I found this. I cornered it. I killed it! What is it? Did things like this catch Pam?" Only a man beside himself could have asked such a question. Holmes carried the corpse of a bird with mottled curly feathers. He'd wrung its neck. He suddenly flung it aside. "Where's Pam?" he demanded fiercely. "What the hell's happened to her? I'll kill anything in creation that's tried to hurt her!" Burke snapped questions. Inane ones. Where had Pam been last? Where were Holmes and Sandy when they missed her? When she cried out? Holmes tried to show him. But this part of the asteroid was a maze of corridors with uncountable doorways opening into innumerable compartments. Some of these compartments were not wholly empty, but neither Burke nor Holmes bothered to examine machine-parts or stacks of cases that would crumble to dust at a touch. They searched like crazy men, calling to Pam. Keller and Sandy arrived. They'd passed the corpse of the bird Holmes had killed, and Keller was strangely white-faced. Sandy panted, "Did you find her? Have you found any sign?" But she knew the answer. They hadn't found Pam. Holmes was haggard, desperate, filled with a murderous fury against whatever unnameable thing had taken Pam away. "Here!" snapped Burke. "Let's get some system into this! Here's the case with the message-cube. It's our marker. We start from here! I'll follow this cross corridor and the next one. You three take the next three corridors going parallel. One each! Look in every doorway. When we reach the next cross-corridor we'll compare notes and make another marker." He went along the way he'd chosen, looking in every door. Cryptic masses of metal in one compartment. A heap of dust in another. Empty. Empty. A pile of metal furniture. Another empty. Still another. Holmes appeared, his hands clenching and unclenching. Sandy turned up, struggling for self-control. "Where's Keller?" "I heard him call out," said Sandy breathlessly. "I thought he'd found something and I hurried--"