"Perhaps," said Uncle Andy, "it's the ionosphere. This is another answer to the danger of hard radiations."
"But not for long," said Henry. "When the critical moment comes there'll be no more atmosphere. What will they do without air?"
"The place is empty," observed Peggy. "Where did the others go?"
That was the principal question.
Twenty minutes later, they stood in a circular room which was roughly forty feet in diameter. In one wall was a mirror, ten feet high. It shimmered like molten silver. They had been in the room twice already.
"What do we do now?" asked Valerie. "Go back to some of those control rooms and start pulling levers?"
"Wait!" exclaimed Martia. "Listen!"
In another moment they could hear the sound of their own breathing. Then—unmistakably—they heard slow, hesitant footsteps.
Valerie and Peggy paled, remembering only too vividly the one-eyed towering creature that had thrown Weston thirty feet through the air. Henry appropriated Valerie's bow and arrow. Uncle Andy, his jaws clamped on a pipe that had long since burned out, took a firm grip on his axe. Pee Bee stood rooted to the floor, unable to do anything but stare in the direction of the curving passageway from which the sounds of the footsteps emanated.
"Weston tried violence against him," whispered Martia to Henry. "Maybe if we—"