"Stand back!" he cried in a terrible voice. "Do not go near that mirror. Above all, do not pass in front of it!"
Mark stared at the savant open-mouthed. His earlier black despair was gone, now, replaced by sudden, inexplicable hope.
"Why not? What's wrong?"
The other licked dry lips.
"Nothing, I hope. The chances are a thousand to one that I am wrong. Yet an idea came to me, my boy. An incredible idea, and a horrible one. And if it is right"—he shook his head slowly—"may God have mercy on Elaine!"
Carefully, then, they approached the mirror. The professor studied it through narrowed eyes from a vantage-point far to one side. At last he turned to Mark.
"Do you notice any defects or flaws in the surface of that glass?" he demanded.
His daughter's fiance nodded.
"The whole thing's out of kilter, professor."
"How would you describe it? What do you mean by 'out of kilter'?"