From the higher elevation where their ship lay he could look out and across this welter of storm-lashed rock to see it level off, then vanish where another crater mouth yawned black. Here was the inner crater! It had seemed small before; it was huge now—a place of mystery, a black, waiting throat into which Chet knew he must go—a place of indefinable terror.
But it was the place, too, whence strange flashes had come, flashes that had told of the distress and suffering of men since the time when wireless waves had been widely used. The old call—the S O S!—it had come from that throat; it had seemed a call sent directly to him! And Chet Bullard's eyes held steadily toward that place of mystery and of a sender unknown.
"I'm going down," he told himself more than O'Malley. "There's something about it I can't understand, something pretty damnable about it, I admit. But, whatever it is, that's what I am here to find out."
"'Tis a divil of a place to die," said O'Malley, "and not one I'd pick out at all. But it may be we won't have to. I'm goin' along, of course."
The master pilot was reaching for the flexible metal suit he had brought from the store room. It was air-tight, gas-proof; it would hold an internal pressure far beyond anything the wearer would demand; and its headpiece was flexible like the body of the suit, and would fit him closely.
He drew the suit up over the clothes he wore and closed the front with one pull of a metal tab. Within, soft rubber-faced cushions had interlocked; the body would fasten to the headpiece in the same way. But Chet paused with the headpiece in his hand.
He looked at the glass window that would be before his eyes; at the thin diaphragms that would come over his ears and that would admit all ordinary sounds; and he tried out the microphone attachment that he could switch on to bring to his ears the faintest whisper from outside. All this he examined with care while he seemed to be thinking deeply. Then he straightened and looked at his companion.
"No, Spud, you're not going," he said. "This is my job. You'll stay with the ship. You and I make a rather small army: we don't know yet what we may be up against, and we mustn't risk all our forces in one advance. I'll see what is there; and, in case anything happens, you can take the ship back. I've taught you enough on the way over; I had this very thing in mind."
He slipped the helmet over his blond head before O'Malley could reply.