It flashed into the doctor's mind that many a woman had fallen in love with a man merely because he seemed to be in need of some one to take care of him.

That is, the self-reliant kind of woman; and Billie certainly was self-reliant. Something of the same notion came vaguely to the geologist at the same time; and with a vigor that was quite uncalled for, he urged:

"I say, 'safety first.' We shouldn't have left the cube unguarded. I propose that one of us, at least, return to the surface while the others attend this meeting—or trap, for all we know."

"All right," said Billie promptly. "Get Estra to show you how to use the elevator, and wait for us in the vestibule."

Van Emmon's face flamed. "That isn't what I meant!" hotly. "If anybody goes to the cube, it should be you, Billie!"

If Billie did not notice the use of her nickname, at least the doctor did. The girl simply snorted.

"If you think for one second that I'm going to back out just because I'm a woman, let me tell you that you're very badly mistaken!"

Van Emmon turned to the doctor appealingly, but the doctor took the action personally. He shook his head. "I wouldn't miss this for anything, Van. Estra looks safe to me. Go and ask Smith; maybe he is willing to be the goat."

The geologist took one good look at the engineer's absorbed, unquestioning manner as he listened to the Venusian, and gave up the idea with a sigh. For a moment he was sour; then he smiled shyly.

"I'm more than anxious to meet the bunch myself," he admitted; and led the way back to Estra. The Venusian looked at him with no change of expression, although there was something very disconcerting in the precocious wisdom of his eyes. Their very kindliness and serenity gave him an appearance of superiority, such as only aggravated the geologist's suspicions.