And where was she now, in her endless explorations? As usual, she was sitting crouched in a swivel chair, while an image built up on the meter-wide screen that dominated one wall of her room. Craig could see that it was in hi-res mode—all two thousand lines—so even the supercomputer was going flat out to paint a pixel every few seconds. To a casual observer, it would have seemed that the image was frozen in a partly completed state; only close inspection would have shown that the end of the bottom line was creeping slowly across the screen.

“She started this run,” whispered Nurse Dolores, “early yesterday morning. Of course, she hasn’t been sitting here all the time. She’s sleeping well now, even without sedation.”

The image flickered briefly, as one scan line was completed and a new one started creeping from left to right across the screen. More than ninety percent of the picture was now displayed; the lower portion still being generated would show little more of interest.

Despite the dozens—no, hundreds—of times that Donald Craig had watched these images being created, they had never lost their fascination. Part of it came from the knowledge that he was looking at something that no human eye had ever seen before—or ever would see again, if its coordinates were not saved in the computer. Any random search for a lost image would be far more futile than seeking one particular grain of sand in all the deserts of the world.

And where was Edith now, in her endless exploring? He glanced at the small display screen below the main monitor, and checked the magnitude of the enormous numbers that marched across it, digit after implacable digit. They were grouped in fives to make it easier for human eyes to grasp, though there was no way that the human mind could do so.

…Six, seven, eight clusters—forty digits all told. That meant—