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 grasp the language of the dawn man. He still did not understand Guru as well as Michaelson did but he could understand enough for his purpose. "Just the two of you going down there?" Michaelson questioned. "Yes. Any more would only increase the chances of discovery. We've got to know the lay of the land and we've got to have some idea of what we will meet down there before we attempt a rescue. We probably will not be able to make an attack before tomorrow night anyhow." After disposing his force and ordering them to get as much rest as possible, Craig and Guru started down to the city of the Ogrum. Michaelson had to be restrained from accompanying them. "You stay here," Craig bluntly told the scientist. "You're not as young as I am and you need a rest." Overhead was a broad tropic moon. There was no wind. From the great swamp came the only sound that broke the silence of the night, the scream of the dinosaurs, the roaring of the great lions of this time. Below lay the strange city of the Ogrum. * * * * *