Leith halted and beckoned to the two girls and Holman, who were some
distance in the rear. "Hurry up!" he cried. "You'll get the sight of
your lives in a few moments."

"What is it?" gurgled the Professor.

Leith grinned as the scientist dipped his lead pencil into his open
mouth so that he would be able to dab down first impressions the moment
he turned his thick lenses upon the wonders.

"You'll see in a moment," replied the big brute, as he walked slowly
forward, and just as he spoke, we did see.

A ridge of bright vermilion came up suddenly about one hundred feet from
the point where the road seemed to dip, and we walked forward wondering
what lay between the spot where the track ended and the bright barrier
of rock that appeared to rise higher as we approached the end of the
trail. We seemed to sense the approach of something that chilled and yet
attracted. The place possessed a devilish fascination. It seemed to
repel with its very uncanniness, and yet I was aware that I was
imitating Holman in thrusting forward my head in an endeavour to see
what filled the space that was hidden from our eyes.

The desire was soon satisfied. Fifteen paces brought us to a point that
left the strange curiosity naked to our eyes. The vermilion walls,
thirty yards in front of us, formed part of the sides of an enormous
circular crater, and we stood spellbound as we pulled up within a few
feet of the ledge and looked into the fearsome depths beneath.

"Ladies and gentlemen," drawled Leith, looking around at us with the