But why? Other mysteries aside, there had plainly been meticulous preparation for the welcoming of a ship from space. No, not welcoming. Acceptance of a ship from space. Somebody had been expected to respond to those plaintive fluting noises which went wailing through the solar system. Who were those waited-for visitors expected to be? What were they expected to do? For that matter, what was the purpose of the asteroid itself? What had it been built for? At some time or another it must have contained thousands of inhabitants. What were they here for? What became of them? And when the asteroid was left--abandoned--what conceivable situation was to trigger the transmitter to send out urgent calls, and then a directional guiding-signal the instant the call was answered? When Burke's ship came, the asteroid accepted it without question and carried out mechanical operations to make it possible for that ship's crew to roam at will through it. What activated this mechanism of so many eons ago? The five newly-arrived humans, three men and two girls, trudged along the echoing gallery cut out of the asteroid's heart. Murmurous sounds accompanied them. Once they came to a place where a whispering-gallery effect existed. They heard their footsteps repeated loudly as if the asteroid inhabitants were approaching invisibly, but no one came. "I don't like this!" Pam said uneasily. Then her own voice mocked her, and she realized what it was, and giggled nervously. That also was repeated, and sounded like something which seemed to sneer at them. It was unpleasant. They came to the end of the gallery. There was a stair leading upward. There was nowhere else to go, so Burke started up, Sandy close behind him, and Holmes and Pam behind them. Keller brought up the rear. They climbed, and small noises began to be audible. They were fluting sounds. They grew louder as the party from Earth went up and up. They reached a landing, and here also there was a metal door with rounded corners. Through it and from beyond it came the piping notes that Burke had heard in his dream some hundreds of times and that lately had come to Earth from emptiness. The sounds seemed to pause and to begin again, and once more to pause. It was not possible to tell whether they came from one source, speaking pathetically, or from two sources in conversation. Sandy went utterly white and her eyes fixed upon Burke. He was nearly as pale, himself. He stopped. Here and now there was no trace of ribbony-leaved trees or the smell of green things, but only air which was stuffy and lifeless as if it had been confined for centuries. And there was no sunset sky with two moons in it, but only carved and seamless stone. Yet there were the familiar fluting sounds.... Burke put his hand to the curiously-shaped handle of the door. It yielded. The door opened inward. Burke went in, his throat absurdly dry. Sandy followed him.