[Illustration:  “Behind the bobbing lamp was the brute who held us in his grip.”]

I attempted to drop on my knees at that minute, but the moment was disastrous to the ambush which we had planned.  As I moved my hand forward I dislodged a skull that was evidently resting upon a shelf somewhat higher than the one before us.  With a noise that appeared terrific in that place, the object crashed down upon the stone, and the bobbing lantern halted about fifteen paces in front of us.

Leith broke the silence that followed.  “What was that?” he asked.

“A bat,” answered Soma.

“I don’t think so,” droned Leith.  “Lift up the light.”

Soma raised the lantern high above his head, and as he did so Holman fired.

The echoes were terrific.  High in the vaulted roof of the place echoes answered each other with the sharp reports of Maxims, and the thick air shivered.

Leith’s voice roared an order.  “Put out the light!”

Soma immediately crashed the lantern upon the ground, and I heard Holman groan.

“I missed him!” he whispered.  “Move along a little, Verslun; they’ve got a line on our position.”

We didn’t move a minute too soon.  Half a dozen shots broke out from the spot where the light of the lantern had been suddenly quenched, and we fired twice and shifted ground the moment we pulled the triggers.

But the opposition guessed the direction of our sidestep.  A bullet lifted my hat into the darkness, and, as I scrambled away, a hand touched my thigh and was immediately taken away.

I felt Holman’s body on the other side, and then, clubbing the big Colt, I drove it down through the darkness at a point that my imagination suggested would be the most likely place to find the head of the stranger whose hand touched my thigh.  The blow missed, and as I made a kangaroo-like jump sideways, a spurt of flame blazed out within a yard of my face.

I fired immediately, and the soft plop of a body settling into the dry dust upon the floor convinced me that I had settled one of our enemies.

For about ten minutes after that there was no more firing.  My skin, more than my ears, brought to my brain the information that there were others somewhere in the thick darkness, but the little air tremors that came to me were so faint that it was impossible to tell in which direction they were.  I had lost all trace of Holman.  With extreme caution I crawled toward what I thought to be the spot where I had left him, but my groping fingers found only the fragments of bone that covered the dusty floor of the charnel house.

I sat in the dust and endeavoured to make my addled brains direct me as to the best course to pursue.  The silence led me to infer that Leith and his party, who were evidently familiar with the cave, were making for the passage by which we had entered the place, and a cold chill passed over me as my imagination pictured Leith, One Eye, and the oily dancers waiting for Holman and me in the narrow corridor.  To escape from the place immediately was our only chance, and with a courage born of terror conjured up by the thoughts of imprisonment in that place of skulls, I started to crawl rapidly into the dark.