r side bludgeoned into it,
and evenly spaced, shrewdly delivered at the vital middle point.
_Whrang, whrang_--even strokes, ringing throughout the barred
laboratory--_whrang ... whrang_....

And then a similar piece settled into clanging routine on another door;
then on the remaining two. The bolts holding them jumped with each
deafening thud. Friday scowled, forgot to search farther for the switch,
took a few short, indecisive steps, and then stood still again, looking
questioningly at his master. The Hawk stood silent also, smoothing the
bangs of flaxen hair above one temple, his face knit in concentration.

He had been afraid they would use the great projector on the door, and
had been somewhat cheered by the reflection that they dared not, for
fear of destroying the contents of the laboratory, especially the
irreplaceable brains. But this was worse; Ku Sui was without question
directing their efforts now. And that being the case, he could expect to
see one door after another battered down--and then a concerted,
four-point rush which would end everything....

* * * * *

Eliot Leithgow said the extraordinary thing that pointed a way out. "May
I suggest," he said mildly, "that we try to get Dr. Ku Sui's brains to
help us?"

"What do you mean?"

The older man smiled, a little sadly. "Those brains--they once were
friends of mine. It's possible they'll answer our questions. It won't
hurt to try. We'll ask them how it might be possible to get out."

Hawk Carse cried: "Eliot, you've got it! There is a chance!"

But the negro shivered. The brains stood for magic, for ghosts--for
awful, unknown things he wanted nothing to do with.

Carse shoved back the screen concealing the infamous device.

"We know where this switch is, at least. If only the current's not been
turned off!"

"Probably not," the Master Scientist said, out of his own technical
thought-train.

Friday hung back, loath to be concerned. He looked askance at the thing,
his open mouth a small round circle.

The Hawk was at the switch, but his hand hesitated. In spite of the
emergency at the doors, in spite of his innate promptness of action, he
hesitated. This thing he was about to do--this awful human mechanism
before him--they were so weird and unnatural....

Then he heard a faint click inside the laboratory--in a place where no
one should be. Instinctively he whirled and crouched--and an orange ray
strea