Rawlins turned back suspiciously, asking why he loitered.  He continued almost indifferently.  He still wanted to know Paredes’s goal, but his disappointment and its meaning obsessed him.

When they crept up the growing light exposed the scars of the deserted house.  Everything was as Bobby remembered it.  At the front there was no decayed wood or vegetation to strengthen the doctor’s half-hearted theory of a phosphorescent emanation.

The tangle of footsteps near the rear door was confusing and it was some time before the three men straightened and glanced at each other, knowing that the doctor’s wisdom was proved.  For Paredes had been there recently; for that matter, might still be in the house.  Moreover, he hadn’t hidden his tracks, as he could have done, in the thick grass.  Instead he had come in a straight line from the woods across a piece of sandy ground which contained the record of his direction and his continued stealth.  But inside they found nothing except burnt-out matches strewn across the floor, testimony of their earlier search.  The fugitive had evidently left more carefully than he had come.  The chill emptiness of the deserted house had drawn and released him ahead of the chase.

“I guess he knew what the light meant,” the detective said, “as well as he did that queer calling.  It complicates matters that I can’t find a woman’s footprints around here.  She may have kept to the grass and this marked-up path, for, since I don’t believe in banshees, I’ll swear there’s been a woman around, either a crazy woman, wandering at large, who might be connected with the murders, or else a sane one who signalled the foreigner.  Let’s get back and see what the district attorney makes of it.”

“It might be wiser not to dismiss the banshees, as you call them, too hurriedly,” Doctor Groom rumbled.

As they returned along the road in the growing light Bobby lost the feeling he had had of being spied upon.  The memory of such an adventure was bound to breed something like confidence among its actors.  Rawlins, Bobby hoped, would be less unfriendly.  The detective, in fact, talked as much to him as to the doctor.  He assured them that Robinson would get the Panamanian unless he proved miraculously clever.

“He’s shown us that he knows something,” he went on.  “I don’t say how much, because I can’t get a motive to make it worth his while to commit such crimes.”

The man smiled blandly at Bobby.

“While in your case there’s a motive at least—­the money.”

He chuckled.

“That’s the easiest motive to understand in the world.  It’s stronger than love.”

Bobby wondered.  Love had been the impulse for the last few months’ folly that had led him into his present situation.  Graham, over his stern principles of right, had already stepped outside the law in backing Katherine’s efforts to save Bobby.  So he wondered how much Graham would risk, how far he was capable of going himself, at the inspiration of such a motive.