ntage--would
be fifteen thousand years. Even that's thousands of years older than any
human civilization; fifteen thousand years ago was the Late Stone Age in
the history of mankind.

"So Leroy and I crept up to those tremendous buildings feeling like
pygmies, sort of awe-struck, and talking in whispers. I tell you, it was
ghostly walking down that dead and deserted street, and every time we
passed through a shadow, we shivered, and not just because shadows are
cold on Mars. We felt like intruders, as if the great race that had
built the place might resent our presence even across a hundred and
fifty centuries. The place was as quiet as a grave, but we kept
imagining things and peeping down the dark lanes between buildings and
looking over our shoulders. Most of the structures were windowless, but
when we did see an opening in those vast walls, we couldn't look away,
expecting to see some horror peering out of it.

"Then we passed an edifice with an open arch; the doors were there, but
blocked open by sand. I got up nerve enough to take a look inside, and
then, of course, we discovered we'd forgotten to take our flashes. But
we eased a few feet into the darkness and the passage debouched into a
colossal hall. Far above us a little crack let in a pallid ray of
daylight, not nearly enough to light the place; I couldn't even see if
the hall rose clear to the distant roof. But I know the place was
enormous; I said something to Leroy and a million thin echoes came
slipping back to us out of the darkness. And after that, we began to
hear other sounds--slithering rustling noises, and whispers, and sounds
like suppressed breathing--and something black and silent passed between
us and that far-away crevice of light.

"Then we saw three little greenish spots of luminosity in the dusk to
our left. We stood staring at them, and suddenly they all shifted at
once. Leroy yelled '_Ce sont des yeux!_' and they were! They were eyes!

"Well, we stood frozen for a moment, while Leroy's yell reverberated
back and forth between the distant walls, and the echoes repeated the
words in queer, thin voices. There were mumblings and mutterings and
whisperings and sounds like strange soft laughter, and then the
three-eyed thing moved again. Then we broke for the door!

"We felt better out in the sunlight; we looked at each other sheepishly,
but neither of us suggested another look at the buildings inside--though
we _did_ see the place later, a