"Who are you and what the hell—" I got this far before I recognized him. Samuel Herker, president of the company that had been organized to develop Tom's inventions commercially. He had gotten rich off of Tom's discoveries, but his main ambition in life was to get richer. "Sorry, Mr. Herker," I called out.

He came across the drive to me. He was hot. "I want to tell you one thing, Shaw!" His voice grated like a dull file being drawn across tough metal. "Either this criminal expenditure of company funds comes to a stop or I'm going into court and ask for the appointment of a referee to conserve the assets of the company, then I'm going to ask for a lunacy hearing to determine if Calhoun is mentally fit to order equipment on company credit without my prior authorization!"

His feet kicked gravel as he stalked across the drive to his own car. The door slammed. The rear wheels spun as he jammed the accelerator to the floorboard. I headed into the lab.

Tom and Ann were there. Their heads close together, they were so deeply engrossed in the papers spread all over the big lab table that they did not hear me enter. How many times had I come in and found them like this, deep in some problem? The sight always made me feel good. Here were two people who were doing their dead-level best to solve some of the problems that confront the human race. All day long and as far into the night as he wanted her, Ann was always in the lab with him, slipping away to steal a few hours of badly needed sleep so that she could return to work bright-eyed and eager the next morning. She was head over heels in love with Tom, and had been since the first day she came to work. So far as I had been able to see, he had never even discovered that she was a woman. A competent research worker, a thorough technician with a keen brain, yes; but a woman, no. He had not noticed that.

"Tom, I didn't want to interrupt, but I just met Herker outside—"

He looked up. A grin came over his face at the sight of me. "Would you like to see what Sam is so upset about?" Without waiting for an answer, he rose and moved to the back wall. New drapes had been hung there. With an expression on his face that said Earth's last secret was about to be revealed, he pulled the drapes aside.

I don't know what I was expecting, but I guess my jaw dropped. Behind the drapes was a painting, of a girl. Her features were even and regular, her eyes looked upward, and her face had a slightly oriental cast. What held my gaze was the haunting quality of her smile. Leonardo Da Vinci had gotten something of this same haunting quality in the Mona Lisa. The girl in this painting smiled out at the world as if she knew everything that had ever been, or ever would be—and was laughing at the efforts of mere mortals to fathom her secret.