planet, Nizar was entirely different from its predecessors. There was
considerable top soil, and here grew a tall reed-shaped plant that gave
off varying chords of sound when the wind blew.

It was as if we were progressing through the nave of a mighty church
with a muted organ in the distance. There was animal life too, a strange
lizard-like bird that rose up in flocks ahead of us and flew screaming
overhead.

"I don't exactly like it, Bagley," he said. "There's something
unwholesome about this planet. The evolution is obviously in an early
state of development, but I get the impression that it has gone
backward; that the planet is really old and has reverted to its earlier
life."

Above us the sky was heavily overcast, and a tenuous white mist rising
up from the _hensorr_ trees formed curious shapes and designs. In the
distance I could hear the swashing of waves on a beach.

Suddenly Mason stopped. "Look!" he said.

Below us stretched the shore of a great sea. But it was the structure
rising up from that shore that drew a sharp exclamation from me. Shaped
in a rough ellipse, yet mounted high toward a common point, was a large
building of multiple hues and colors. The upper portion was eroded to
crumbling ruins, the lower part studded with many bas-reliefs and
triangular doorways.

"Let's go," Mason said, breaking out into a fast loping run.

The building was farther away than we had thought, but when we finally
came up to it, we saw that it was even more of a ruin than it had at
first appeared. It was only a shell with but two walls standing, alone
and forlorn. Whatever race had lived here, they had come and gone.

We prowled about the ruins for more than an hour. The carvings on the
walls were in the form of geometric designs and cabalistic symbols,
giving no clue to the city's former occupants' identity.

And then Mason found the stairs leading to the lower crypts. He switched
on his ato-flash and led the way down cautiously. Level one ... level
two ... three ... we descended lower and lower. Here water from the
nearby sea oozed in little rivulets that glittered in the light of the
flash.

We emerged at length on a wide underground plaisance, a kind of
amphitheater, with tier on tier of seats surrounding it and extending
back into the shadows.

"Judging from what we've seen," Mason said, "I would say that the race
that built this place had reached approximately a grade C-5 of
civilization, according