Harry turned to Jim.
"Come," said he, and led the way beneath the darkened archway. Cortes and Fernando followed at their heels.
But Harry Urquhart had not taken ten paces forward when he stood transfixed in wonderment at the solemn magnificence and beauty of the Caves of Zoroaster.
The place was like a great cathedral. It was divided into three aisles by two lines of pillars. These pillars were extraordinarily massive. They had not been built up from the floor to the ceiling, but were part of the living rock, joining the roof to the floor. In other words, the aisles had been hollowed out by human labour, and the rounded pillars left at regular intervals to support the immense weight above.
The cave was lighted from above by several shafts that pierced the mountain, and which threw convergent beams of light across the shadows. Giving upon each of the side aisles were three doors constructed of wood, but barred with iron and studded with scores of nails. Above these doors, around three sides of the cave, was a kind of gallery, connected with the roof by a series of smaller and more frequent pillars.
At the far end, upon an altar, a single oil-lamp was burning. Behind the altar, and about twenty paces distant, was a wall of rock which immediately attracted the attention of the boys.
This rock was rough, as in its natural state, whereas elsewhere in the cave—on the floor, the ceiling, and the pillars—the rock was so smooth that it resembled masonry. Moreover, the aisles were of grey limestone; but the rock behind the altar was of red granite, in which the quartz and mica crystals glittered in the flickering light of the lamp.
By the side of the granite rock was something which Harry Urquhart recognized at once. On a single axis, supported at each end by grooves cut in the pillars, were nine enormous wheels of bronze. On the outside—or what would correspond to the "tyres"—of each of these wheels, were hundreds of strange cuneiform characters.
There was no doubt that beyond the red granite rock lay the vault which contained the treasure, and these wheels composed the Bramah lock by sole means of which the vault itself could be opened.
But without the Sunstone the wheels were useless. On the obverse side of the Sunstone was the explanation, or solution, of the riddle.