Tarzan was sure that there was another and more lovely world than that which was confined to the darkness of the four stone walls surrounding him. He continued his search and at last found the doorway leading inward beneath the city and the temple. This he followed, most incautiously. He came to the stone steps leading upward to the higher level. He ascended them and continued onward toward the well.

Nothing spurred his hurt memory to a recollection of past familiarity with his surroundings. He blundered on through the darkness as though he were traversing an open plain under the brilliance of a noonday sun, and suddenly there happened that which had to happen under the circumstances of his rash advance.

He reached the brink of the well, stepped outward into space, lunged forward, and shot downward into the inky depths below. Still clutching his spear, he struck the water, and sank beneath its surface, plumbing the depths.

The fall had not injured him, and when he rose to the surface, he shook the water from his eyes, and found that he could see. Daylight was filtering into the well from the orifice far above his head. It illumined the inner walls faintly. Tarzan gazed about him. On the level with the surface of the water he saw a large opening in the dark and slimy wall. He swam to it, and drew himself out upon the wet floor of a tunnel.

Along this he passed; but now he went warily, for Tarzan of the Apes was learning. The unexpected pit had taught him care in the traversing of dark passageways—he needed no second lesson.

For a long distance the passage went straight as an arrow. The floor was slippery, as though at times the rising waters of the well overflowed and flooded it. This, in itself, retarded Tarzan’s pace, for it was with difficulty that he kept his footing.

The foot of a stairway ended the passage. Up this he made his way. It turned back and forth many times, leading, at last, into a small, circular chamber, the gloom of which was relieved by a faint light which found ingress through a tubular shaft several feet in diameter which rose from the center of the room’s ceiling, upward to a distance of a hundred feet or more, where it terminated in a stone grating through which Tarzan could see a blue and sun-lit sky.

Curiosity prompted the ape-man to investigate his surroundings. Several metal-bound, copper-studded chests constituted the sole furniture of the round room. Tarzan let his hands run over these. He felt of the copper studs, he pulled upon the hinges, and at last, by chance, he raised the cover of one.

An exclamation of delight broke from his lips at sight of the pretty contents. Gleaming and glistening in the subdued light of the chamber, lay a great tray full of brilliant stones. Tarzan, reverted to the primitive by his accident, had no conception of the fabulous value of his find. To him they were but pretty pebbles. He plunged his hands into them and let the priceless gems filter through his fingers. He went to others of the chests, only to find still further stores of precious stones. Nearly all were cut, and from these he gathered a handful and filled the pouch which dangled at his side—the uncut stones he tossed back into the chests.

Unwittingly, the ape-man had stumbled upon the forgotten jewel-room of Opar. For ages it had lain buried beneath the temple of the Flaming God, midway of one of the many inky passages which the superstitious descendants of the ancient Sun Worshipers had either dared not or cared not to explore.