"Sure I do, Bob," Blair said worriedly. "Do you think I haven't beaten out my brains over it? I know the idea's monstrous. But just suppose there was a branch of humanity—if you could call it human—living off us unsuspected. A branch that knows how to eliminate—competition—almost by instinct."
"Now hold on a minute, Jim. You've taken Jean's reaction to this last death, plus a random association with a cuckoo clock, and here you are with a perfectly wild hypothesis. You've always been rational and analytical, old man. Surely you can realize that a perfectly normal urge to rationalize Jean's conclusions is making you concur with them against your better judgment."
"Bob—"
"I'm not through, Jim. Just consider how fantastic the whole idea is. Because of a series of accidents you can't accuse a child of planned murder. Nor can you further hypothesize that all orphans are changelings, imbued with an instinct to polish off their foster-siblings."
"Not all orphans, Bob. Not planned murder, either. Take it easy. Just some of them. A few of them—different. Growing up. Placing their young with well-to-do families somehow, and then dropping unobtrusively out of the picture. And the young growing up, and always the natural children dying off in one way or another. The changeling inherits, and the process is repeated, step by step. Can you say it's impossible? Do you know it's impossible?"
"I wouldn't say impossible, Jim. But I would say that your thesis has a remarkably low index of probability. Why don't others suspect, besides you?"
Jim spread his hands hopelessly. "I don't know. Maybe they do. Maybe these creatures—if they do exist—have some means of protection we don't know about."
"You need more than maybes, Jim. What about Joanna Simmons' mother? According to your theories she should have been well off. Was she?"
"No, she wasn't," Jim admitted reluctantly. "She came here and took a job with my outfit. Said she was divorced, and had lived in New York. Then she quit to take a position in California, and we agreed to board Joanna until she got settled. Warrenburg was the town. She was killed there quite horribly, in a terrible auto accident."
"Have you any reason for suspecting skulduggery? Honestly, Jim? Or for labelling her one of your human—er—cuckoos?"