Wilmer and Hayes sipped their coffee, waiting with forced patience for the parapsychologist to speak.

Presently, Flinn shivered and looked up at them. "If he says he can control a critical mass, or erase Washington, D. C., or destroy the nation, you'd better believe him."

"He's telling the truth then," Hayes said grimly.

"Yes," Flinn answered. "Here are my findings. Somehow Dobbs has established rapport with the atom. Any atom. Probably any number of atoms. I doubt if he can move one single mass in the ordinary conception of psychokinesis. That is, I doubt if he can cause a pebble, say, to shift one millimeter. What he can control are the forces that bind atoms into molecular structures, or that hold nuclei together. Do you understand what I mean? For example, what he did up there just now was to get rid of the space between atoms in the molecules of that water carafe. I saw it clearly; there's no mistake. The space ceased to exist, the atoms crashed in upon each other, and the carafe seemed to disappear. The mass is the same. It's simply in a different form."

He paused and scanned the numb faces of the government agent and the nuclear physicist beside him.

"Let's get down to specifics," he continued. "What's his trump card? What is it he's holding over our heads?"

"The atmosphere," Wilmer said painfully.

"Oxygen," Flinn mused. "Suppose Dobbs concentrated upon the oxygen atoms all around us and caused their nuclei suddenly to fuse. What would happen?"

"Nobody on the face of the Earth would know what hit him," Wilmer said. "The Moon would probably be blasted out of its orbit. And if there is any intelligent life on Mars, they'd be treated to a sight they'd never forget—if they survived it."

"Well, then," Flinn said, "we've done what we came here to do. What's the answer?"