He threw the curve down on his desk and, soothed by the whirring of the tracer motor, fell into a brown study. Suddenly, the image of the brunette with the violet eyes appeared. No reclining nude, she; she shook her head in that habitual gesture and her long bob fell perfectly in place. She turned, with demurely downcast lashes and looked up at him with her violet eyes, and Norm came out of his trance with a start.
He removed the last curve—a simple hyperbolic curve, probably a problem in attenuation or decay of some kind—and put in the last punch-card. The machine started up immediately; the curve was elliptical. Then a vertical down-stroke, retraced and with a gentle half-loop added. It was writing! P-r-o-p-i-n-q.... What might this be? He watched, fascinated, as the letters continued. "Propinquity is the mother of love," it said, and stopped.
His trained mathematical logic gave him an immediate solution to the enigma: he was cracking up. It was utterly impossible to derive the equation to write "propinquity" in Spencerian script in less than a hundred man-hours, nor could a mathematical calculator be hired for so frivolous a purpose. It was fantastic, impossible; therefore, it was not so, and he was either dreaming or crazy. Maybe thinking about that little brunette.... Surely not; still, he had been driving himself pretty hard. In the morning he would be fresh and alert. If it were a trick, he'd catch the trickster. And if it turned out to be a perfectly logical curve, he'd see a doctor.
He left the curve in the machine, closed the ventilator in the wall over his desk, and turned on the burglar alarm. This was nothing so crude as a loose board with a switch, but a quite elaborate electronic circuit that produced a field near the door. It wouldn't work on ghosts, but if any material body entered that field, it would trip the alarm and start a regular Mardi Gras. Security required by government contracts hardly demanded so much, but for a small plant it was sufficiently cheap, and Charley had had a lot of fun with it. Charley! Have to keep him out, too; and being its daddy, he'd know how to disable the alarm. Of course, it would really be sufficient to tie a thread across the door which would break if anyone entered. He had no thread, but after a moment's thought, he pulled a three-cent stamp out of his bill-fold, and turned out the office-light. After glancing up and down the hall, he stuck the stamp on the door so that it would tear if the door opened.
n the morning, the stamp was still intact, and it was hard to see, even in broad daylight. The paper in the curve-tracer was perfectly blank, and there was no punch-card in the transmitter head. It might still be an elaborate joke, but the chances were small. He might be cracking up, or may have imagined the whole thing. The best thing to do would be to put it entirely out of his mind.
He succeeded in this until mid-morning, when ICWEA called him a "handsome devil." He jerked the punch-card out of the transmitter and called Vic.
"Hermosa."
That voice! It made chills run up and down his backbone. A man had no right to a voice like that. "Vic? Bring up the calculations for the last batch of punch-cards, will you? I want to check something. The card numbers are F-141 through F-152."