not even touched by the common run of men.

"Well," he began, "to put it very simply, the device indicates whether
or not a man's mental ... ah ... processes are being influenced by
outside ... by outside influences." He gave the cameras another little
smile. "If you will allow me, I will demonstrate on the machine itself."

He took two steps that carried him out of camera range, and returned
wheeling a large heavy-looking box. Dangling from the metal covering
were a number of wires and attachments. A long cord led from the box to
the floor, and snaked out of sight to the left.

"Now," Dr. O'Connor said. He selected a single lead, apparently, Malone
thought, at random. "This electrode--"

"Just a moment, doctor," Burris said. He was eying the machine with a
combination of suspicion and awe. "A while back you mentioned something
about 'outside influences.' Just what, specifically, does that mean?"

With some regret, Dr. O'Connor dropped the lead. "Telepathy," he said.
"By outside influences, I meant influences on the mind, such as
telepathy or mind reading of some nature."

"I see," Burris said. "You can detect a telepath with this machine."

"I'm afraid--"

"Well, some kind of a mind reader anyhow," Burris said. "We won't
quarrel about terms."

"Certainly not," Dr. O'Connor said. The smile he turned on Burris was as
cold and empty as the inside of Orbital Station One. "What I meant was
... if you will permit me to continue ... that we cannot detect any sort
of telepath or mind reader with this device. To be frank, I very much
wish that we could; it would make everything a great deal simpler.
However, the laws of psionics don't seem to operate that way."

"Well, then," Burris said, "what does the thing do?" His face wore a
mask of confusion. Momentarily, Malone felt sorry for his chief. He
could remember how he'd felt, himself, when that law professor had come
up with a particularly baffling question in class.

"This machine," Dr. O'Connor said with authority, "detects the slight
variations in mental activity that occur when a person's mind is _being_
read."

"You mean, if my mind were being read right now--"

"Not right now," Dr. O'Connor said. "You see, the bulk of this machine
is in Nevada; the structure is both too heavy and too delicate for
transport. And there are other qualifications--"

"I meant theoretically," Burris said.

"Theoretically," Dr. O'Connor began, and smiled again, "if your mind
w