upside-down crescent of the moon and the smaller blue thumbnail slice of the Earth. Spence flew into the netting, tucked his head down, and landed on his back. He pulled himself across the net to a near wall.
Above him a group of cadets performed an intricate display of aerial acrobatics-doing flips and somersaults across the center of the dome. Around the perimeter several joggers sped along the track; another group ran perpendicular to the first. A couple of fluffy pidg birds floated down near the lift platform. No one seemed interested in getting up a game, so Spence swam to the edge of the net and walked up the great bulging sphere of the dome to the red strip designated as the track.
The track's surface bore a slightly irregular, bumpy grain which gave a runner that little extra bit of traction needed to get moving in zero gravity. Spence carefully set his feet on the track and then started walking smoothly, with exaggerated care; one false step and he would go spinning off toward the center of the dome. But he maintained his concentration and increased the pace, feeling the illusion of weight return to him. Actually it was only momentum he felt, and which held him to the track. Soon he was running easily around the inner wall of the dome.
He caught the other joggers on the track and fell into pace with them. In the rhythm of running his muscles relaxed and the tension flowed from him. Automatically his body took over and his mind turned once again to the enigma of his dreams.
That he dreamed was certain. His REM line on the scan showed plainly what he knew instinctively, and if he required further proof the emotional residue-that silt left behind when the angry waters had raced on-was real enough. Not to remember a dream was normal enough; one remembered only the tiniest fraction of one's dreams over a lifetime. They simply flitted by in the night-spun out of the stuff of the subconscious and reabsorbed into the fabric of the psyche upon waking.
But blackouts were not normal. Spence felt as if whole chunks of his life were missing. There were gaps in his memory which he could not cross, dark curtains behind which he could not see. That scared him.
More than the nightmares, more than the cargo bay incident, he feared the helplessness, the utter defenselessness of not knowing what was happening to him. The carefully reasoned and researched framework of his life teetered precariously, threatening to topple completely, and he did not know what to do about it.
He lowered his head and spurted past the others. His lungs burned and sweat stung his eyes, but he continued running faster and faster as if to escape the fear which came swimming out of the darkness of the star-spangled night beyond the netting. Closing his eves he thrust the fear from him as if it were a solid object he could throw aside. …
AFTER HIS RUN SPENCE lay motionless in the center of the dome, turning slowly on his own axis like a minor planet. The warm glow of exertion throbbed through his limbs. He had reached that blissful state of exhaustion where body and spirit were reconciled one to the other and the universe hummed with peace.
He listened to the play of others and watched through halfclosed lids as the red line of the track circled him aimlessly. It was, he thought, a tribute to the supreme egotism of the mind that he seemed completely stationary while the entire space city of Gotham revolved around him. Around and around it went, spinning in its own lazy orbit-now the black mirror of the observation bubble, now the red line of the track.
The red line of the track. Something about that seemed important. Spence jerked his head up and sent himself floundering away at an obtuse angle. In the same instant it came to him: the red line of the track was the red line of his sleep scan. He had meant to check it, but had forgotten, or the thought had been driven from his mind by the circumstances of his latest blackout.
Suddenly it seemed more important than ever. He dove for the nearest wall and then propelled himself toward the lift platform. He raced back to the lab with his heart pounding and the certainty drumming in his brain that he was very close to finding an answer to the riddle of his dreams.
10
… SPENCE SNAPPED THE SEAL and unrolled the strip to the beginning, watching meters and meters of paper tape unwind through his fingers. At the start of the tape he saw the date and time notation: EST 5/15/42 10:17 GM. The scan continued for nine and three-quarter hours without interruption. Each peak and every valley, every blip of an alpha spark or beta flash was duly recorded. He saw the minute fluctuations in cerebral blood flow; the rise and fall of body temperature, heart rate, and thyroid activity; the intermittent REM flutters. He saw, in short, the even, rhythmic progress of his night's sleep. His every moment was accounted for. Undeniably so-he held the evidence in his own hands.
But it was not enough. He turned to the cabinet where all the spools were kept. There were dozens of them, each one containing the polysomnographic information of one night's sleep session. He lifted the row containing the scans of the last week. He checked each one. They were all there, labeled and sealed correctly.
He checked the week before that and the next one, too. All was in order. Tickler was as precise as he was stuffy. Spence knew that if he looked at every spool over the last ten weeks he would find them in order. Still, a small gray shadow of doubt clung to his mind.
He turned once more to the scan he had unrolled-the one from the night of his first blackout three days ago. He pulled the tape through his hands and examined it closely. It was no different from all the others.
He spied the yellow plastic cover of the log book on the corner of the console and pulled it to him. On top of the log book lay a piece of green graph paper on which was plotted the averages Spence had requested for the last three sessions. Kurt must have come in and finished it while he was out. He glanced at the graph of the averages and then opened the log book and traced up the columns to the session of the fifteenth. He found no irregularities in any of the figures or information. He closed the book with the sinking feeling that all was in order and only he was out of sync.
He threw the book down on the console and leaned back with his hands clasped behind his head. If an answer existed to his problems it would have to exist in some form in the hard data before him. Somewhere in the miles of tape, or in the figures in the book, the key to the locked room of his mind could be found. Of that he was certain. His faith in the scientific method stood on solid, unshakable rock.
On a whim he swiveled to the data screen at one end of the console. The wafer-thin, half-silvered glass shone smooth as polished stone. 'MIRA,' said Spence, 'Spence Reston here. Ready for command.'
A mellifluous female voice said, 'Ready, Dr. Reston,' Spence uttered the simple command: 'Compare entries for PSG Seven Series LTST five-fifteen to five-eighteen for similarties. Display only, please.'
He laced his fingers behind his head and leaned back in his chair. Instantly the wafer screen flashed to life and the results began filling the screen. It seemed there were many similarities between one night's scan and the next in terms of basic numerical components. All of the information gathered during a scanning session was translated into numbers for purposes of data storage and retrieval. They were all alike in many ways, and yet all different.
The command was too broad. That much he could see, but he did not know how to narrow the question because he did not know precisely what he was looking for. He crossed his arms over his chest and frowned at the screen. Just what did he hope to find?
After several minutes of hard thought he stood and began pacing the cramped confines of the booth. Compare and contrast, he thought. That's where you start on a fishing expedition of this type. Compare and contrast.
He had already compared and that had not shown him anything out of the ordinary. Perhaps contrasting the same information would produce something. He turned to the screen and said, 'Contrast PSG LTST entries for five-fifteen to five-eighteen. Display only, please.'
The numbers vanished and in their place the screen began printing: Zero contrast within normal range of variability ± 3%. In other words, dead end.
Spence glanced at the digiton above the console. In a few minutes Tickler would arrive to begin the session. He did not want Tickler to find him here like this playing detective. A silly thought he knew-1 have a perfect right to examine the data of my own experiment, for goodness sakes-but he preferred that Tickler should know nothing about his inquiry.
Judging he had time for two more stabs in the dark, he said, 'Compare PSG LTST Seven Series entries five- fifteen to five-eighteen for similarities of less than one percent variability. Display only, please.' He nodded with
