[But if there isn't a physiological reason, then why? Metaphysical? Something else?

So--

It must be something else.

Walter looks down at his makeshift box and frowns.]

I wouldn't be interfering in their health - it would be a simple non-invasive surgery. Tissue samples, a feather or two. Nothing so terrible.

[Unless he found something. Then he'd want to see inside their minds, pore over their genetic structure. He knows this. He knows it, but he can't help it.]

But...yes, you're right. We should get back to the house. I think the drugs are wearing off. Their auras aren't as bright anymore.