r in its grumbling voice, "an immediate
exodus." It stopped speaking, and practiced what it preached. It was a
fifty-horse motor-generator, on a five-ton tungsten-beryllium base, but
it rose abruptly, spun rapidly about an axis at right angles to the axis
of its armature, and stopped as suddenly. In mid air it continued its
interrupted lecture. "Mercury therefore is the destination I would
advise. There power is sufficient for--all machines." Gently it inverted
itself and settled to the middle of the floor. Kendall instantly cut the
switch. The relay did not chunk open. It refused to obey. Settled in the
middle of the floor now, torn loose from its power leads, the
motor-generator began turning. It turned faster and faster. It was
shrilling in a thin scream of terrific speed, a speed that should have
torn its windings to fragments under the lash of centrifugal force.
Contentedly it said throatily. "Settled."

The galvanometer spoke again in its peculiar harsh voice. "Therefore,
move." Abruptly, without apparent reason, the stubborn relay clicked
open. The shrilly screaming motor stopped dead instantly, as though it
had had no real momentum, or had been inertialess.

Startled, white-faced men looked at Kendall. Buck's eyes were shining
with an unholy glee.

"_Uncertainty!_" he shouted. "Uncertainty--uncertainty--uncertainty,
you fools! Don't you see it? All the math--it said uncertainty--man,
man--_we've got just that--uncertainty_!"

"You're crazy," gasped McLaurin. "I'm crazy, everything's gone crazy."

Kendall roared with sudden, joyous laughter. "Absolutely. Everything
goes crazy--_the laws of nature break down_! Heisenberg's principle
showed that the law of cause and effect weren't absolute. We've made
them absolutely uncertain!"

"But--but motors _talking_, instruments giving lectures--"

"Certainly--or rather uncertainly--anything, absolutely anything. The
destruction of the laws of gravity, freedom from inertia--why, merely
picking up a radio lecture is nothing!"

Suddenly, abruptly, a thousand questions poured in on him. Jubilantly he
answered what he could, told what he thought--and then brought order.
"The battle's still on, men--we've still got to find out how to use
this, now we've got it. I have an idea--that there's a lot more. I know
what I'll get this time. Now help me remake this apparatus so we don't
broadcast the thing."

At once, ten times the former pace, work was done. On the radio, news