I pushed Drake into the newly opened way and sprang after him.
Behind us was an unbroken wall covering all that space in which but a moment before we had stood! Is it to be wondered that a panic seized us; that we began to run crazily down the alley that still lay open before us, casting over our shoulders quick, fearful glances to see whether that inexorable, dreadful closing was continuing, threatening to crush us between these walls like flies in a vise of steel?
But they did not close.

Unbroken, silent, the way stretched before us and behind us.

At last, gasping, avoiding each other's gaze, we paused.
And at that very moment of pause a deeper tremor shook me, a trembling of the very foundations of life, the shuddering of one who faces the inconceivable knowing at last that the inconceivable--IS.
For, abruptly, walls and floor and roof broke forth into countless twinklings! As though a film had been withdrawn from them, as though they had awakened from slumber, myriads of little points of light shone forth upon us from the pale-blue surfaces--lights that considered us, measured us--mocked us.
The little points of living light that were the eyes of the Metal People! This was no corridor cut through inert matter by mechanic art; its opening had been caused by no hidden mechanisms! It was a living Thing--walled and floored and roofed by the living bodies--of the Metal People themselves.
Its opening, as had been the closing of that other passage, was the conscious, coordinate and voluntary action of the Things that formed these mighty walls.
An action that obeyed, was directed by, the incredibly gigantic, communistic will which, like the spirit of the hive, the soul of the formicary, animated every unit of them.
A greater realization swept us.

If THIS were true, then those pillars in the vast hall, its towering walls--all this City was one living Thing! Built of the animate bodies of countless millions! Tons upon countless tons of them shaping a gigantic pile of which every atom was sentient, mobile--intelligent! A Metal Monster! Now I knew why it was that its frowning facade had seemed to watch us Argus-eyed as the Things had tossed us toward it.

It HAD watched us! That flood of watchfulness pulsing about us had been actual concentration of regard of untold billions of tiny eyes of the living block which formed the City's cliff.
A City that Saw! A City that was Alive! No secret mechanism then--back darted my mind to that first terror--had closed the wall, shutting from our sight Norhala at play with the Little Things.