le further along, we found
shelter. Snap murmured: "The girls went past here. But which way,
Gregg?"

As though I knew!

I felt at that moment, under the shirt against my skin, the anode of
my audiphone tingling. A receiving signal! In the gloom, I could see
Snap's white face as he watched me bring it out.

We heard a tiny microphonic voice, Anita's voice.

"Colonel Halsey. Yes I have the location. Lafayette 4--East corridor,
lowest level. A descending entrance. Don't you speak again; I've only
a minute! Venza safe--but send help. Something we don't understand--a
strange mechanism here."

Then Halsey's interrupting voice. "Anita, escape! You and Venza!"

"We can't. They've got us!"

"I'm sending men. They'll be there in ten minutes."

"Ten minutes will be too late. Molo is...."

It seemed that we heard her scream; then the waves blurred and died.

Lafayette 4--East corridor, lowest level. "Snap, that's here! A
descending entrance."

We stood back against the great curving side of the postal vacuum
tube. Within it I heard the hiss and clank as a mail cylinder flashed
past. Halsey's secret orders must be going out now. His men nearest
this place would come in a rush. But Anita said that would be too
late.

Snap and I were frantically searching. Somewhere here was an entrance
to Molo's lair. It seemed in the silence that Anita's scream was still
ringing in my ears. Had it been entirely from the instrument, or were
we so close that we had heard its distant echoes?

"Gregg, help me." Snap was tugging at a horizontal door-slide, like a
trap in the tunnel floor, partly under the vacuum tube. "Stuck!" he
gasped.

It yielded with our efforts. It slid aside. Steps led downward into
blackness. We plunged in, caution gone from us. The steps went down
some twenty feet; we were in another smaller corridor. It was vaguely
lighted by a glow from somewhere, and as my pupils expanded, I could
see this was a shabby alley, opening ahead into a winding passage with
the slide-port above us like its back gate. A warren of cubbies was
here, a little sequestered segment of disreputable dwellings.

We stood peering, listening. "Shall I try the eavesdropper, Gregg?"

"Yes. No, wait!" I thought I heard distant sounds.

"Voices, Snap. Listen."

More than voices. A thud: footsteps running. A commotion, back in this
warren, within a hundred feet of us.

"This way," I murmured.

We plunged into a black gash. There was a glow