uru, by devious paths known only to the dawn man, had
guided them here. Below them lay the city of the Ogrum.

The city was located on the edge of a huge, circular bay that had
apparently at some time in the remote past been the crater of a large
volcano. To the east where the walls of the volcano had crumbled down
was a vast swamp, a favorite feeding ground for the dinosaurs. Hundreds
of the great beasts could be heard screaming and fighting in the swamp.

The city itself held Craig's eyes.

He had seen the Ogrum in airplanes, he had seen them use gas, both of
which meant an advanced civilization, with a great knowledge of
technology. He had expected to find a city bright with lights, numbering
hundreds of thousands of inhabitants, with large factories, broad
streets, and--since they used planes--landing fields.

None of these things was visible. The city of the Ogrum was unlighted.
There were no wide streets, no factories in sight. There was only one
large building in the city, and the buildings which apparently served as
homes for the Ogrum were little better than crude huts. There was a
brilliant full moon overhead, clearly revealing the whole scene.

"It's not possible!" Craig whispered to Michaelson. "This can't be the
city of the Ogrum. Guru brought us to the wrong place."

The scientist questioned Guru. Craig could hear the dawn man's replies.

"Guru says this is the right place," Michaelson spoke. "He says this is
the city of the Ogrum, that there is no other city."

"But with the exception of that temple, this place is a dump!" Craig
protested. "I have seen Papuan head-hunters who had built more
pretentious cities than this. The Ogrum have planes. You can't build
planes without a complex industrial system."

"It is certainly strange," the scientist said musingly. "But Guru
insists this is the place and I am inclined to believe him. You will
note also that the city below us is not laid out in streets and I see no
evidence of a lighting system."

"Maybe they've got a black-out on," a sailor suggested.

Guru, consulted on this point, said no, the city of the Ogrum was always
dark at night. Guru had a great deal of difficulty in understanding what
was meant by light, but once he grasped the idea, he insisted the Ogrum
never used lights.

"Well, it's a damned mystery," Craig said. "And I'm going down there and
find out about it. Guru, come with me."

Craig had spent the hours in the boats trying to gr