Black Gods and Scarlet Dreams by C. L. Moore

suppose we'll never really know. Must have had some relation to the other — the white thing, possibly some force or element out of that other dimension; because just as dark couldn't touch the whiteness of that thing, so light had no effect on the dark. I got the impression, somehow, that the dark space is a fixed area there, as if a section out of the other world has been set down in the cave, for the white thing to roam about in — a gather of blackness across the way. And I don't suppose that it can move outside the darkness. But I may be wrong — let's go!”
    “Right behind you!” said Yarol. “Get along.”

    The cave extended for another fifteen-minute walk, cold and silent and viciously rough underfoot, but no further mishap broke the journey. Tomlinson lights gleaming, they traversed it, and the glow of cold day at the far end looked like the gleam of paradise after that journey through the heart of the dead rock.
    They looked-out upon the ruins of that city where once the gods had dwelt — jagged rock, great splintered teeth of stone upflung, the bare black mountainside folded and tortured into wild shapes of desolation. Here and there, buried in the debris of ages, lay huge six-foot blocks of hewn stone, the only reminder that here had stood Mars' holiest city, once, very long ago.
    After five minutes of search Smith's eyes finally located the outline of what might, millions of years ago, have been a street. It led straight away from the slope at the cave-mouth, and the blocks of hewn stone, the crevices and folded ruins of earthquake choked it, but the course it once had run was not entirely obliterated even yet. Palaces and temples must have lined it once. There was no trace of them now save in the blocks of marble lying shattered among the broken stones.
    Time had erased the city from the face of Mars almost as completely as from the memories of man. Yet the trace of this one street was all they needed now to guide them.
    The going was rough. Once down among the ruins it was difficult to keep in the track, and for almost an hour they clambered over broken rock and jagged spikes of stone, leaping the crevices, skirting great mounds of ruin. Both were scratched and breathless by the time they came to the first landmark they recognized — a black, leaning needle of stone, half buried in fragments of broken marble. Just beyond it lay two blocks of stone, one upon the other, perhaps the only two in the whole vast ruin which still stood as the hands of man had laid them hundreds of centuries ago.
    Smith paused beside them and looked at Yarol, breathing a little heavily from exertion.
    “Here it is,” he said. “The old boy was telling the truth after all.”
    “So far,” amended Yarol dubiously, drawing his heat-gun. “Well, we'll see.” The blue pencil of flame hissed from the gun's muzzle to splatter along the crack between the stones. Very slowly Yarol traced that line, and in spite of himself excitement quickened within him. Two-thirds of the way along the line the flame suddenly ceased to spatter and bit deep. A blackening hole appeared in the stone. It widened swiftly, and smoke rose, and there came a sound of protesting rock wrenched from its bed of eons as the upper stone slowly ground half around on the lower, tottered a moment and then fell.
    The lower stone was hollow. The two bent over curiously, peering down. A tiny breath of unutterable antiquity rose in their faces out of that darkness, a little breeze from a million years ago. Smith flashed his light-tube downward and saw level stone a dozen feet below.
    The breeze was stronger now, and dust danced up the shaft from the mysterious depths — dust that had lain there undisturbed for unthinkably long ages.
    “We'll give it awhile to air out,” said Smith, switching off his light. “Must be plenty of ventilation, to judge from that breeze; and the dust will probably blow away before long. We can be rigging up some sort of ladder while