For an hour the little expedition rested upon the mountain-top,
and then Tarzan led them down into the valley below. There was no
trail, but the way was less arduous than the ascent of the opposite
face of the mountain had been. Once in the valley their progress
was rapid, so that it was still light when they halted before the
towering walls of the ancient city.

The outer wall was fifty feet in height where it had not fallen
into ruin, but nowhere as far as they could see had more than ten
or twenty feet of the upper courses fallen away. It was still a
formidable defense. On several occasions Tarzan had thought that
he discerned things moving behind the ruined portions of the wall
near to them, as though creatures were watching them from behind
the bulwarks of the ancient pile. And often he felt the sensation
of unseen eyes upon him, but not once could he be sure that it was
more than imagination.

That night they camped outside the city. Once, at midnight, they
were awakened by a shrill scream from beyond the great wall. It
was very high at first, descending gradually until it ended in a
series of dismal moans. It had a strange effect upon the blacks,
almost paralyzing them with terror while it lasted, and it was an
hour before the camp settled down to sleep once more. In the morning
the effects of it were still visible in the fearful, sidelong glances
that the Waziri continually cast at the massive and forbidding
structure which loomed above them.

It required considerable encouragement and urging on Tarzan's part
to prevent the blacks from abandoning the venture on the spot and