The professor whistled.  Here was enlightenment indeed!  A very sufficient explanation of the old man’s grim determination to block any self-dependence on desire’s part which would mean “removal from” his “care.”  Here was someone paying a steady (and perhaps a fat) allowance for the young girl’s maintenance—­someone of whom she herself had certainly never heard and of whose bounty she remained completely ignorant.  It was easy enough now to follow Li Ho’s reasoning.  If it was for this allowance, and this alone, that the old doctor had kept Desire with him, long after her presence had become a matter of indifference or even of distaste, the ending of the allowance meant also the ending of his tolerance.  “No more safe, being married.”  The difference, in Li Ho’s opinion, was all the difference between comparative safety and real danger.  Money!  As long as Desire had meant money there had been an instinct in the old scoundrel which, even in his moon-devil fits, had protected the goose which laid the golden eggs.  But now—­now this inhibition was removed, Desire, no longer valuable, was no longer safeguarded.  And who could tell what added grudge of rage and vengeance might be darkly harbored in the depths of that crafty and unbalanced mind?

And Desire, unwarned, was even now almost within the madman’s reach. . . .  Spence sternly refused to think of this . . . there was time yet . . . plenty of time. . . .  The thing to do was to keep cool . . . steady now!

“Kind of pretty, going through these here mountains by moonlight,” observed the tobacco traveller, inclined to be genial even under difficulties.  “She’ll be full tomorrow night.  Queer thing that them there prohibitionists can’t keep the moon from getting full!” He laughed in hearty appreciation of his own cleverness.

The professor, a polite man, tried to smile.  And then, suddenly, the meaning of what had been said came home to him.

Tomorrow night would be full moon!

He had forgotten about the moon.

“Queer cuss,” thought the travelling man.  “Stares at you polite enough but never says anything.  No conversation.  Just about as lively as an undertaker.”

But if Benis had forgotten to remove his eyes from the travelling man, he did not know it.  He did not see him.  He saw nothing but moonlight—­moonlight across an uncovered floor and the white dimness of a bed in the shadow! . . .  But he must keep cool . . . was there time to stop Desire with a telegram?  She was only a day ahead . . . no—­he was just too late for that.  He knew the time-table by heart.  Her train was already in . . . impossible to reach her now!