p, the ten-foot insect-like shapes of workers. Three or
four of the brains came bouncing up, moving along the ground catwalk
with little leaps. All the figures entered the distant main dwelling
house. The contact was over.

"Probably hardly anyone left down below," Snap whispered. "Now's our
chance."

"If we can get into that opening without being seen," I said.

"Shadows, down the rocks to the left. Damnation, Gregg, we can make it
in one calculated leap."

"I'll try it first. I'll get in and wait for you."

"Right."

We each had a gravity cylinder at our belt and a ray-gun in our hand.
The slope of the depression was dim here, merely starlit; it was a
steep, broken and fairly shadowed descent, fifty feet to the little
dome-like kiosk which marked the nearest subterranean entrance. I went
down it with a swoop, landed in a heap beside the kiosk and ducked
into it. Instinct made me fear a guard, but reason told me none would
be here; there was only the danger of encountering someone coming up.

I was at the top of a winding, descending passage, a step-terraced
floor; there were occasional lights in the ceiling. In a moment Snap
joined me. "Got here! I wonder how far down it goes?"

I gripped him. "Snap, no matter what happens, do it with a rush. Keep
with me. And if I shout to get out...."

"We go out with a rush!"

"Yes. Back to the girls. Use your ray-gun and the gravity projector in
getting back to them and get away without me, if I fall."

"Same for you, Gregg."

We went down the deserted passage. We had had experience in movement
on Wandl now; we handled ourselves more deftly. We went down several
hundred feet. The passage branched, but there always seemed a main
tunnel.

It was all deserted. There were distant, dimly-lighted, silent rooms.
Were these factories of the strange forms of electronic gravity
currents Wandl used? Some were in operation. A hum issued from them.
Workers moved about.

We stopped to consult. The girls, and Molo himself, had described what
we would find: a main route leading to the control room where the
delicate mechanisms which operated all this were centralized, the
nerve center of Wandl. It seemed that we were following that main
route.

A worker came with a swimming leap past us. We dropped into a hollowed
shadow at a tunnel intersection, and he went swooping by.

"Lord, Snap," I muttered, "that was too close for comfort."

Again we advanced. The tunnel turned sharp