"It was. Down behind a rock-mass or something."
We waited, watching closely, but those yellow eyes did not gleam again through that Stygian gloom.
"Must have been at quite a distance," I remarked at last.
"It seems so, Bill; and that means that this cavern is very straight for a mile or more or that it is one of enormous size."
"It may be both."
"It may be, of course," he nodded. "And it may be that those lights were not so far away as they appeared to us to be. One may easily be deceived in such matters."
"We don't know what this means," I said; "but we know this: we're spotted."
"Oh, we're seen, all right, Bill. Our every movement will be watched."
Some minutes passed, during which we stood peering down the cavern and waiting; but no light gleamed forth again.
Then we started back.