by Bob Shaw
As he stood at the rail, transfixed, he became aware that the incredible spectacle was drifting down the sky at undiminished speed. He turned and saw that Steenameert was staring out past him, jaw sagging, with eyes which had become reflective white disks—miniature versions of the phenomenon which was mesmerizing him.
"A quarter turn I told you," Toller bellowed. "Check the rotation."
"Sorry, sir." Steenameert stirred into action and the lateral jet mounted low down on Toller's side of the gondola began to spew miglign gas. Rings of condensation rolled away from it through the gelid air. The sound of the jet was puny, quickly absorbed by the surrounding void, but it gradually achieved the intended effect and the skyship came to rest with its vertical axis parallel to the sea of white fire.
"What's going on out there?" The querulous voice of Trye Kettoran issuing from the passenger compartment helped bring Toller out of his own tranced condition.
"Have a look over the side," he called out for the commissioner's benefit, then turned to Steenameert. "What do you think yonder thing is? Ice?"
Steenameert nodded slowly. "Ice is the only explanation I can imagine, but. ..."
"But where did the water come from? There is the usual supply of drinking water in the defense stations, but that amounts to no more than a few barrels. ..." Toller paused as a new thought struck him. "Where are the stations, anyway? We must try to locate them. Are they embedded in the. . . ?" His voice failed altogether as related questions geysered through his mind. How thick was the ice? How far away from the ship was it? How wide was the enormous circular sheet?
How wide is the circle?
The last question suddenly reverberated in his consciousness, excluding all others. Until that instant Toller had been overawed by the brilliant spectacle confronting him, but it had inspired no sense of danger. There had been a feeling of wonder—but no threat. Now, however, certain facts of aerial physics were beginning to assume importance. A disturbing importance. A potentially lethal importance. . . .
He knew that the atmosphere which enveloped the sister planets was shaped like an hourglass, the waist of which formed a narrow bridge of air through which skyships had to pass. Old experiments had established that ships had to keep near the center of the bridge—otherwise the air became so attenuated that the crews were bound to asphyxiate. Largely because of the difficulty of taking measurements in the region, there was some uncertainty about the thickness of that core of breathable air, but the best estimates were that it was no more than a hundred miles in diameter.
The enigmatic sea of sun-blazing ice was rendered featureless by its brilliance, and in the absence of spatial referents it could have been hovering "beside" the skyship at a distance of ten miles, or twenty, or forty, or . . . Toller could think of no way to ascertain its distance, but he could see that it spanned almost one third of the visual hemisphere, and that gave him enough information to perform an elementary calculation.
Lips moving silently, he stared at the radiant disk while he dealt with the relevant figures, and a coldness which had nothing to do with the harsh environment entered his system as he reached a conclusion. If the disk proved to be as much as sixty miles away—which it could quite easily be—then, by the immutable laws of mathematics, it was sufficiently wide to block the air bridge between Land and Overland. . . .
"Sir?" Steenameert's voice seemed to come from another universe. "How far would you say we are from the ice?"
"That is an excellent question," Toller said grimly, taking the ship's binoculars from the control station locker. He aimed them at the disk, striving to pick out detail, but could see only a shimmering field of brightness. The sun was now fully occulted, spreading its light more evenly over the vast circle, making an estimate of its distance more difficult than before. Toller turned away from the rail, knuckling round green after-images from his eyes, and examined the height gauge. Its pointer was perhaps a hair's breadth below the zero-gravity mark.
"You can't rely much on those devices, sir," Steenameert commented, unable to resist showing off his knowledge. "They are calibrated in a workshop, with no allowance for the effect of low temperatures on the springs, and—"
"Spare me," Toller cut in. "This is a serious matter—I need to know the size of that. . . thing out there."
"Fly towards it and take note of how it expands."
Toller shook his head. "I have a better idea. I have no intention of turning back unless all other options are denied me—therefore we will fly towards the edge of the circle. Its exact diameter in miles is not all that significant. The truly important thing is to ascertain whether or not we can fly our ship around the obstacle.
"Do you wish to remain at the controls?"
"I would value the experience, sir," Steenameert replied. "What burner rhythm do you require?"
Toller hesitated, frowning, frustrated by the fact that no practicable air speed indicator had ever been developed for use on skyships. An experienced pilot could get some idea of his speed from the slackening of the rip line as the crown of the balloon was depressed by air resistance, but the abundance of variables made accuracy impossible. It would not have been beyond Kolcorronian ingenuity to devise a reliable instrument, but the motivation had never been present. A skyship's job was to crawl up and down between the planetary surface and the weightless zone—a journey which always took roughly five days on each leg—and a difference of a few miles an hour was neither here nor there.
"Give it two and six," Toller said. "We shall pretend to ourselves that we are making twenty miles in the hour and base all our estimates accordingly."
"But what is the nature of the barrier?" Commissioner Kettoran said from close behind Toller. He was in an upright position, holding the edge of the cane partition with one hand and keeping a quilt around him with the other.
Toller's first impulse was to request him to lie down again to achieve the complete rest which had been prescribed by the base physician, then it occurred to him that in the absence of weight it made no difference which attitude was adopted by a person with a heart condition. Allowing his thoughts to be diverted into irrelevancies, he visualized a new use for the pathetic little group of defense stations in the weightless zone. Properly heated and supplied with good air, they could best serve as rest centers for those with certain kinds of ailment. Even a cripple would be. . . .
"I'm addressing you, young Maraquine," Kettoran said peevishly. "What is your opinion of that curious object?"
"I think it might be made of ice."
"But where would such a vast quantity of water come from?"
Toller shrugged. "We have had rocks and even pieces of metal descend on us from the stars—perhaps the void also contains water."
"A likely story," Kettoran grumbled. He gave a theatrical shrug and his long, solemn face—now purple with the cold —slowly sank from view as he returned to his cocoon of downy quilts.
"It's an omen," he added, his voice muffled and indistinct from behind the partition. "I know an omen when I see one."
Toller nodded, smiling thinly in skepticism, and returned to his vigil at the gondola's rail. By calling out-the firing times for the various lateral jets he helped Steenameert guide the ship into a course which closed with the fire-sheet at an unknown angle, aiming it for the westernmost edge. The main jet was roaring in a steady two-six rhythm and Toller knew that the ship's speed could easily be as much as his putative twenty miles an hour—but the aspect of the sheet did not alter noticeably with the passing of the minutes.
"Our friend, the omen, appears to be a veritable giant," he said to Steenameert. "We may have some trouble in getting around him."
Wishing he had the simple navigational instruments available on the humblest airship, Toller kept his gaze on the eastern rim of the great circle, willing it to descend and thus prove that the ship was making significant progress. He was just beginning to convince himself that he could indeed see a change in the vital angle, when the glowing sheet was
swept by waves of prismatic color. They moved at breathtaking orbital speed, crossing the entire disk in mere seconds and stilling Toller's heart with their message that cosmic events were taking place, reminding him of how unimportant the affairs of mankind were when measured against the grandeur of the universe. The sun, already hidden from his view by the icy screen, was being further occulted by Overland. As soon as the bands of color—engendered by the refraction of the sun's light in Overland's atmosphere—had fled into infinity the disk's overall luminosity began to decrease. Night was falling in the weightless zone.
Here, so close to the datum plane, the terms "night" and "littlenight" no longer had any relevance. Each diurnal cycle was punctuated by two periods of darkness approximately equal in length, and Toller knew it would be some four hours before the sun reappeared. The hiatus could hardly have come at a more inconvenient time.
"Sir?" Steenameert, a sentient pyramid of swaddling in the fading light, had no need to voice the full question.
"Keep going, but reduce thrust to one and six," Toller ordered. "We can shut down the jet altogether if we find we can't keep a check on our course. And be sure to keep the balloon well inflated."
Grateful for Steenameert's competence, Toller remained at the rail and studied the disk. Sunlight was still being reflected from Land—which was now directly behind him— so the icy wall remained visible, and with the change in illumination he began to see hints of an internal structure. There was a tracery of the palest violet, arranged like rivers which divided and kept on dividing until they faded from the sight, lost in distant shimmers.
They're like veins, Toller thought. Veins in a giant eye. . . .
As Land was gradually enveloped in Overland's shadow the disk steadily darkened to near-blackness, but its edge was still clearly defined against the cosmic background. The rest of the sky was now ablaze with its customary extravagance of galaxies—glowing whirlpools ranging from circles to slim ellipses—plus formless ribbons of light, myriads of stars, comets and darting meteors. Against that luminous richness the disk was more mysterious than ever—a featureless well of night which had no right to exist in a rational universe.
By occasionally ordering a slight pendulum movement of the ship Toller was able to look ahead and satisfy himself that it was on course for the disk's western edge. As the hours of darkness dragged by the air became progressively thinner and less satisfying to the lungs, evidence that the skyship was far from the center of the invisible bridge that linked the two worlds. Although Commissioner Kettoran did not voice any complaint, his breathing became clearly audible. He had mixed some firesalt with water in a vellum bag and could be heard sniffing from it at frequent intervals.
When at last daylight returned, heralded by a brightening of the disk's western rim, Toller found he could see the rim without having to tilt the ship. Perspective returned; geometry again became a useful tool.
"We're only a mile or so from the edge," he announced for the benefit of Steenameert and Kettoran. "In a few minutes we should be able to work around it and head back into the good air."
"It's about time!" Kettoran scowled face appeared above the passenger compartment partition. "How far to the side have we travelled?"
"Perpendicular to the ideal course, we must have done in the region of thirty miles—" Toller glanced at Steenameert and received a nod of confirmation—"which means we are dealing with a lake, a sea, of ice some sixty miles across. I find it hard to credit what I'm saying, even though I am looking straight at the thing. Nobody in Prad is going to believe what we say."
"We may have corroboration."
"By telescope?"
"By your lady friend—Countess Vantara." Kettoran dabbed a drop of moisture from the end of his nose. "Her ship departed not so many days before ours."
"You're right, of course." Toller was dully surprised to realize he had forgotten about Vantara for several hours. "The ice . . . the barrier . . . whatever it is . . . may have been in place when she made the crossing. It is something we will have to confer over in detail."
Having derived an unexpected grain of comfort from the discussion—a readymade reason to seek out Vantara, wherever she might be—Toller gave his attention to the task of steering his ship around the edge of the disk. The maneuver was not a difficult one in theory. AH he had to do was pass the western rim by a short distance, carry out a simple inversion and begin flying back into the thicker air at the core of the atmospheric bridge.
Leaving Steenameert at the controls, he remained by the rail in order to obtain the most advantageous viewpoint and started giving detailed handling instructions. The ship was moving very slowly as it drew level with the rim, probably at no more than walking pace, but after some minutes had passed it came to Toller that it was taking longer than he had expected to reach the limit of the ice wall. Suddenly suspicious, he trained his binoculars on the rim. The sun was close to his aiming point, hurling billions of needles of radiance into his eyes and making the viewing difficult, but he managed to get a clear look at the icy boundary. It was now less than a furlong away in reality, and the image in his glasses brought it much closer.
Toller grunted in surprise as he discovered that the rim of the ice sheet was alive.
In place of what he had expected—the inertness of frozen water—there was a kind of crystalline seething. Glassy prisms and spikes and branches, each as tall as a man, were sprouting outwards on the rim with unnatural rapidity. They were extending the boundary of the sheet with the speed of billowing smoke—each thrusting into the gelid air and glistening in the sunlight for a moment before being overtaken and assimilated by others in the racing, sparkling vitreous foment.
Toller stared at the phenomenon, tranced, his mind awash with the unexpected and incredible beauty of it, and it seemed a long time before the first coherent thought came to him: The rim of the barrier is moving outwards at almost the same speed as the ship!
"Increase speed," he shouted to Steenameert, his voice strained by the bitter coldness and the inimical nature of the thinning air. "Otherwise you'll never see home again!"
Commissioner Kettoran, who had seemed almost a well man during the passage through the weightless zone, had been struck by a fresh seizure when the ship was only a few thousand feet above the surface of Overland. In one second he had been standing with Toller at the gondola's rail and pointing out familiar features in the landscape below; in the next he was lying on his back, unable to move, eyes alert and afraid, beaconing an intelligence trapped inside a machine which no longer responded to its master's bidding. Toller had carried him to his nest of quilts, wiped the frothy saliva from the corners of his mouth, and had gone immediately for the sunwriter in its leather case.
The lateral drift had been greater than usual, bringing the ship down some twelve miles to the east of the city of Prad, but the sunwriter message had been picked up in good time. A sizeable group of coaches and mounted men—plus a sleek airboat in grey-and-blue royal livery—had been waiting in the touchdown area. Within five minutes of the landing the commissioner had been transferred to the airboat and sent on his way to an emergency audition with Queen Daseene, who was waiting in the overheated confines of her palace.
There had been no opportunity for Toller to pass on any words of reassurance or farewell to Kettoran, a man he had come to regard as a good friend in spite of the disparity in age and status. As he watched the airboat dwindle into the yellow western sky he became aware of a sense of guilt and it took him some time to identify its source. He was, of course, deeply concerned about the commissioner's health, but at the same time—and there was no getting around the fact—one part of him was thankful that the older man's misfortune had come along, like the answer to a prayer, exactly when he had needed it. No other circumstance that he could readily think of could have placed him back on Overland and within reach of Vantara in such a short time.
What sort of monster am I? he thought, shocked by his own selfishness. I must be the w
orst. . . .
Toller's bout of introspection was interrupted by the sight of his father and Bartan Drumme descending from a coach which had just arrived at the landing site. Both men were attired in grey trews and three-quarter-length tabards gored with blue silk, a formal style of dress which suggested they had come straight from an important meeting in the city. Toller strode eagerly to meet his father, embraced him and then shook hands with Bartan Drumme.
"This is truly an unexpected pleasure," Cassyll Maraquine said, a smile rejuvenating his pale triangular face, 'it is a great shame about the commissioner, of course, but we must assume that the royal physicians—a plentiful breed in these times—will quickly put him to rights. How have you been, son?"
"I am well." Toller looked at his father for a moment in that unique gratification which springs from an harmonious relationship with a parent, and then—as extraneous matters crowded into his mind—he shifted his gaze to include Bartan Drumme in what had to follow. The latter was the only surviving member of a fabled voyage to Farland, the local system's outermost planet, and was acknowledged as Kolcorron's leading expert on astronomical matters.
"Father, Bartan," Toller said, "have you been observing the skies within the last ten or twenty days? Have you noticed anything unusual?"
The older men exchanged cautiously surprised glances. "Are you speaking of the blue planet?" Bartan said.
Toller frowned. "Blue planet? No, I'm talking about a barrier ... a wall ... a lake of ice . . . call it what you will . . . which has appeared at the midpoint. It is at least sixty miles across and growing wider by the hour. Has it not been observed from the ground?"
"Nothing out of the ordinary has been observed, but I'm not even sure that the Glo telescope has been in use since—" Bartan broke off and gave Toller a quizzical stare. "Toller . . . Toller, you can't nave an accretion of ice at the midpoint—there simply isn't the water. The air is too dry."