in the family stage but they have not yet learned to live together
in tribes."

Michaelson sounded as if he thought this discovery was of the utmost
importance. Scientifically, it probably was important. But Craig had
other things on his mind.

"Ask him who he thought we were when he first saw us," he said. "Ask him
why he was so badly scared of us. Ask him who the Ogrum are."

Craig was talking to the scientist but he was watching Guru. When he
mentioned the Ogrum, the dawn man flinched. Fright appeared in his eyes.
Michaelson spoke to him, consulting a notebook in which he had already
jotted down words that he had learned, and listened carefully to his
reply. The scientist turned to Craig.

"Guru says the Ogrum are very bad," he said. "He says they are much
fiercer than the _death-that-flies_, by which he means the bird that was
attacking him when we came up. He says the Ogrum fly too, and that they
are like us, only different. He says he thought we were Ogrum when he
first saw us. He says the Ogrum hunt down his people, and capture them,
and take them to their city, and there feed them to the monster that
eats forever."

"The monster that eats forever!" Craig whistled thoughtfully. "What the
devil is that?"

Michaelson repeated Craig's question to Guru. The answer came haltingly,
slowly. The scientist turned to Craig. "I am not at all certain what he
means. Another definition would be the bright beast that is always
hungry. But I do not know what this beast is, and Guru seems unable to
tell me. He has never seen it, he says, only heard about it. He is much
afraid of the Ogrum."

"I don't blame him," Craig said. "But what are they?"

Guru seemed unable to grasp the meaning of this question. He showed a
strange disinclination to discuss the subject. He was so much afraid of
the Ogrum that he did not even want to talk about them. And yet--this
fact put a worried frown on Craig's forehead--Guru was no coward. They
had seen him fearlessly face the flying dragon, the death-that-flew.
What was there about the Ogrum that made Guru so terribly afraid of
them?

Guru seemed nervous and uneasy. He looked all around the ravine as
though he sensed the presence of hidden danger. Suddenly he looked up. A
single word fell from his lips.

"_Ogrum!_" he whispered. "_Ogrum!_"

Craig looked skyward. A single wedge-shaped plane was diving on silent
wings through the air. His first thought was that it was diving at them.
Th