"Where?"
"There—standing by that window. You can see the window and curtain in the photograph."
The Tracer gazed intently at the picture.
"She looked at me," said Harren, steadying his voice. "She was as real as you are, and she stood there, smiling faintly, her dark, lovely eyes meeting mine."
"Did you speak?"
"No."
"How long did she remain there?"
"I don't know—time seemed to stop—the world—everything grew still. . . . Then, little by little, something began to stir under my stunned senses—that germ of misgiving, that dreadful doubt of my own sanity. . . . I scarcely knew what I was doing when I took the photograph; besides, it had grown quite dark, and I could scarcely see her." He drew himself erect with a nervous movement. "How on earth could I have obtained that photograph of her in the darkness?" he demanded.
"N-rays," said the Tracer coolly. "It has been done in France."
"Yes, from living people, but—"