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 of light, a glassite pane in a house wall nearby. The commotion was louder, and under it now we heard a vague humming: something electrical. It was an indescribably weird sound, like nothing I had ever heard before. Snap clutched at me. "In here, but where is the accursed door?" There was a glassite pane, but we could find no door. In our hands we held small electronic bolt-cylinders, short-range weapons. The hum and hissing was louder. It seemed to throb within us, as though vibration were communicating to every fiber of our bodies. Light was streaming through the glassite pane, and we glimpsed the interior of the room. The light now came from a strange mechanism set in the center of the metal cubby. I caught only an instant's glimpse of it, a round thing of coils and wires. The metal floor of the room was cut away, exposing the gray rock of Manhattan Island. And against the rock, in a ten-foot circle, a series of discs were contacted, with wires leading from them to the central coils. The whole was glowing with opalescent light. It was dazzling, blinding. Within in it the goggled figure of Molo was moving, adjusting the contacts. He stooped. He straightened, drew back from the light. Only an instant's glimpse, but we saw the girls, crouching with black bandages on their eyes. Meka, goggled like her brother, was holding them. A tall shape carrying a round black box darted through the light and ran. Molo leaped for the girls; the hum had mounted to a wild electrical scream. Molo flung his sister back out of the light. They all vanished. There was nothing but the light, and the mounting dynamic scream. Beside me, Snap was pounding on the glassite panel. I joined him. Everything was dreamlike, blurring as though unconsciousness was upon me.