ed as we crept up to it. Gazing above
me, I could see the top of the dam, now looming above the Power House.
There was a break in the spillway at this point. The arching cascade
of water under which the catwalk hung ended here. We came out where
there was a vista of the lower Hudson beneath us, showing dimly down
past the docklights and skeleton landing stages to the bay.

* * * * *

The sky was visible now and the open wind struck us full. It was a
crazy pendulum wind. A storm was breaking overhead. There were flares
of lightning and thunder cracks--from disturbed nature, outraged by
the temperature changes of the Robot's red and violet rays.

The Power House, so far as we could see, was dark and deserted. Its
normal lights were extinguished. Was Tugh in there? It was my weapon
against his. The white-ray was new to Tina; we had no way of
estimating this cylinder's effective range.[3]

[Footnote 3: The cylinder of the white-ray which I carried was not the
one with which Tugh murdered Harl. Mine was portable, and considerably
smaller.]

I kept Tina and Larry well behind me. It was a desperate approach, and
I was well aware of it. The catwalk now was illumined at intervals by
the lightning; Tugh from many points of vantage in the Power House
could have seen us and exterminated us with a soundless flash swift as
a lightning bolt itself. But we had to chance it.

We reached the small lower platform. The catwalk terminated. The Power
House was a roof over us. I stood at the foot of the spiral staircase,
which went up through a rectangular opening in the floor. There was a
vista of a dark room-segment.

"Keep behind me," I murmured, and I started up. Was Tugh lurking here,
waiting for me to raise myself above this opening? If he had been, he
could have held his position against a score of assailants.

But he was not. I soon stood breathlessly in a dark metal room. Tina
and Larry came up.

"He's not here," I whispered. It was more silent in here: the
cascading water was further away from us now. There came a flash of
lightning, followed in a few seconds by its accompanying thunder
crash.

I started. "What's that?"

* * * * *

On the floor near us lay a gruesome, crumpled thing. I bent over it,
waiting for another flash. When one came I saw it was a heap of
clothes, covering a white skeleton. By the garments Tina knew it was
one of the guards.

We c