Kay moved forward cautiously, still holding Ruth. He seemed to be skirting the edge of a vast crater. At the edge of it he found the top, revolving slowly. And Cliff's voice came from beside the top.
"Kay, we've won. Don't look at me. Don't let Ruth see me! Look down!"
Kay looked down into the bottomless pit, extending clear across the plain to the distant jungle. An enormous canyon cloven in the earth, filled with the slowly settling cloud of dust.
"They're there, Kay. Don't look this way!"
But Kay looked—and could see nothing except a pile of debris, from the bottom of which Cliff's voice issued.
"Cliff, you're not hurt?"
"A—a little. You must listen while I tell you how to clean up the monsters. It's the psenium emanation. It has the same effect when our method is applied to it. It disintegrates everything inorganic—not organic.
"I thought, if I couldn't get them, I'd crumble the earth away—bury them. They're underneath the debris, Kay, a mile deep, buried, beneath the impalpable powder that represented the inorganic salts and minerals of the earth. They'll never get out of that. Protoplasm needs oxygen. They'll trouble us no more.
"You must take the top, Kay. Use our old method. You'll find its application to the psenium emanation written in a book fastened beneath the hood. Wipe out the rest of them. If any more come, you'll know how to deal with them."
"Cliff, you're not badly hurt?" Kay asked again.