"Yes," said Slim.
"Here's a hundred-dollar bill," Tom Ellingbery said. "Start shadowing my wife; get something on her. I'll give you five thousand to get something—ten if it's necessary," he said with a slight leer.
Slim gravely picked up the C note. "We don't do business that way," he said; "but if your wife has been misbehaving we'll find it out."
Ellingbery was a big man with a sharp go-getter look about him. He stared hard at Slim and Slim stared back. Ellingbery's expression didn't show anything; then he left.
Slim locked the door after Ellingbery, and I took off my pants and set up the ironing-board on the desk. Slim went back to adjust the dials on his machine.
"This gadget is a sort of super-sensitive radar," he said as it warmed up. "I can tune it to your brain-waves and pick you up anywhere within forty miles or three months."
A purple indicator began to wink. "It proves I've got brains, anyway," I pointed out.
"Yes, your waves come in at a frequency of approximately 1,832,956,000. That's as close as I can tune it so far, but that's plenty close enough. There are other characteristics, such as power and damping and height of crest and so on, that make it selective enough to pick out any one person in the United States if it could reach that far."
"And then you can see everything I do?"