another tiny lever thickly encrusted with
rust, secreted behind a movable brick in the first tier below the lake's
bottom. This he placed in position, securing it in a niche so that it
became immovable.

"Now," he said, "we may descend without fear," and with these words knelt
down, and after lighting a torch he had brought with him, commenced the
descent into the cavernous gloom. I quickly followed, my feet resting
for a brief instant upon the fatal iron projection, but no spikes came
forward, for the terrible mechanism was now locked. Deep down into this
circular shaft we went, the smoke and sparks from Omar's torch ever
ascending into my face as I lowered myself from rung to rung, until at
last, at considerable depth, we found ourselves in a kind of natural
cavern. The place seemed damp and full of bad odours, to which submitting
with patience we, by a long passage, sometimes crawling under rugged
arches, sometimes wading in mud and dirt, attained the end of the cavern,
where we stumbled on some narrow steps; but the torch shed little light,
and we became nearly suffocated by the noisome vapours.

"I thought you said the air was fresh here," I exclaimed good-humouredly
to my companion.

"So I did," he answered. "I cannot make out why it has become so foul.
The air-holes must have become accidentally stopped up."

The widening ascent was so intricate and clogged with dirt and rubbish
that we worked like moles in the dark; nevertheless, by diligent industry
we gained ground considerably, yet as we endeavoured to mount, the slimy
steps slipped from under us, and ever and anon we would come tumbling
down with a weight of dirt upon us.

After various labours, however, we suddenly entered a great cavern, quite
dry. From its roof hung great stalactites that glittered and sparkled in
the torch's uncertain light, while around the rough walls of this natural
chamber were heaped in profusion great heavy chests of iron and adamant.

With the torch held high above his head Omar rushed across to the pile
and bending, examined one chest after the other. Then, raising himself
as the truth suddenly dawned upon him, he cried in a hoarse, excited
voice:

"By the power of Zomara, we have been tricked!"

"Tricked! How?" I gasped in alarm.

"Cannot you see?" he wailed. "This, the Treasure-house of the Sanoms, has
been entered and its contents, worth a fabulous sum, have been extracted!
See! Each trunk has been forced by explosi