the mighty granite kopje, outside the city's walls, where lay the
entrance to the passage-way leading to the treasure vault, gave
the Belgian ample cover as he followed Tarzan toward Opar.

He saw the giant ape-man swing himself nimbly up the face of the
great rock. Werper, clawing fearfully during the perilous ascent,
sweating in terror, almost palsied by fear, but spurred on by
avarice, following upward, until at last he stood upon the summit
of the rocky hill.

Tarzan was nowhere in sight. For a time Werper hid behind one of
the lesser boulders that were scattered over the top of the hill,
but, seeing or hearing nothing of the Englishman, he crept from
his place of concealment to undertake a systematic search of his
surroundings, in the hope that he might discover the location of the
treasure in ample time to make his escape before Tarzan returned,
for it was the Belgian's desire merely to locate the gold, that,
after Tarzan had departed, he might come in safety with his followers
and carry away as much as he could transport.

He found the narrow cleft leading downward into the heart of the
kopje along well-worn, granite steps. He advanced quite to the
dark mouth of the tunnel into which the runway disappeared; but
here he halted, fearing to enter, lest he meet Tarzan returning.

The ape-man, far ahead of him, groped his way along the rocky
passage, until he came to the ancient wooden door. A moment later
he stood within the treasure chamber, where, ages since, long-dead
hands had ranged the lofty rows of precious ingots for the rulers
of that great continent which now lies submerged beneath the waters