Hours later Craig stood on the side of a mountain looking down at an incredible scene. Guru, 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 d.a.m.ned 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.

Craig felt the weirdness of the scene as he and Guru started down the side of the mountain. What kind of creatures were the Ogrum? What secret lay behind their existence? They had left no mark on history as he knew it. So far as the human race knew, the Ogrum had never existed. And yet--the sudden thought was startling--there was a word in the English language that came close to describing these creatures--ogre! Ogre and Ogrum were very similar. Were these the original ogres, those mythological monsters who devoured human beings? Had the Ogrum, known, feared, and named by the dawn men, come down through legends as ogres?

The thought sent a shivery feeling up Craig's spine. Was he going down into a city of monsters? Were Stinky Higgins and Margy Sharp and hundreds of men from the Idaho held as prisoners by ogres? What horrible secret was hidden down there in that silent city?

They reached the edge of the city. It was larger than Craig had thought.

Hundreds, possibly thousands of rude huts, were hidden in the jungle growth. The place smelled bad. Apparently no effort at sanitation had ever been made. A nauseous stench arose from the ground. Craig wrinkled his nose in disgust.

"Filth!" he muttered. "This place needs nothing so much as it needs burning to the ground. Where Ogrum, Guru?" he said, turning to the dawn man.

"Ogrum sleep," Guru answered. "In little caves," he said, nodding toward the huts. "Ogrum sleep."

"Where prisoners?" Craig asked. He had to rephrase the question and repeat it several times before the dawn man understood.

"In big cave," Guru said, understanding at last.

"Where big cave?" Craig asked.

"Big rock cave," Guru answered, pointing toward the large stone temple that stood in the center of the city.

"Then that is where we are going," Craig said. "Come on."

Guru hung back. Craig sensed the dawn man's fear. "What's wrong?" he asked.

"Monster that is always hungry in big cave," Guru answered.

"Ah," Craig said. The monster that is always hungry! The bright beast that eats forever! A shiver pa.s.sed through him as he remembered how Guru had described whatever was in the cave. "What is the monster?" he questioned.

But Guru either did not understand or could not explain, and Craig was left with no knowledge of the nature of the monster. However he could guess that the Ogrum regarded the thing in the temple as a G.o.d and offered sacrifices to it, an impression which Guru confirmed.

"Tomorrow when sun goes," Guru said. "Ogrum feed one man to bright beast that is always hungry. Next day when sun goes feed beast again. Keep up until no one left to feed. Then go hunt more people."

Craig recognized the performance as an incredibly ancient ritual of sacrifice to ensure the return of the sun. The Ogrum seemingly had no real knowledge of the universe. Each night when the sun went down they were not sure that it would rise again. To make certain the bright light in the sky would return again, they offered a sacrifice to it.

"What do they do when they run out of captives?" he asked.

"Catch Ogrum, feed him to beast," the dawn man answered.

When they ran out of captives, the Ogrum sacrificed their own people!

"Well, we've still got to find out what is in that temple and where our people are being held," Craig said grimly. "If Guru is afraid, Guru may stay here. I will go alone."

Guru was afraid. There was no doubt about that. Craig did not criticize the dawn man for being afraid. He regarded it as evidence of good, sound sense. But, afraid or not, Guru went with him. Slipping like a pair of ghosts through the rough paths that served as streets, they entered the silent city. Guru was as noiseless as a shadow, and Craig, every sense alert, moved as quietly as an Indian. The big American knew that from any of the huts an Ogrum might emerge at any moment.

They reached the temple un.o.bserved.

It was a bigger building than had been apparent from the mountain above.

Unlike the huts, it was constructed of stone. Roughly circular in shape, a line of columns circled the outer edge. The construction was crude.

The Ogrum either had not yet invented the arch or scorned to use it.

Numerous holes big enough for a man to enter standing erect, but not much bigger, served as entrances. The holes were without doors, another invention the Ogrum apparently had not yet made, and Craig was again struck by the strangely warped development of this race that knew how to build airplanes and to use poison gas but still did not know how to build arches.

Unlike the city, the temple was guarded. Yellow-robed, shaven-headed sentries paced around the building keeping inside the circles of the columns.

"Friends of the bright beast that is always hungry," Guru called them.

Craig decided they were priests, temple guards. He saw they were armed with spears and swords. In addition each guard carried a pouch of small, round objects that looked like grenades.