“Such as?”

“Circuits. For this synthetic gravity.”

“No. I don’t think we’ll find any circuits in our sense of the word.”

“What then?”

“Atoms with their interiors rearranged or specially designed to do a job. Perfect machines.”

“It sounds incredible.”

“We’ve taken the first step in that direction ourselves with our magnetic resonance engines. Anyway, what could be more incredible than all this?” Some instinct prompted Garamond to push the soil back into the hole and tamp it down with his foot, repairing the damage he had done to the grassy surface. In the region close to the aperture the soil was thinly distributed, but there were hills in the distance which looked as though they could have been formed by drifting. “As soon as your men have got over the shock tell them to gather vegetation and soil samples,” he said.

“I already have,” Kraemer replied carelessly. “By the way — none of the suit radios is working, though mine was all right again when I went back out through the aperture.”

“There must be a damping effect — that’s something else for O’Hagan to investigate when he gets here. Let’s have a look at some of those ruins.”

They walked to the nearest of the indistinct mounds. Under the blanket of climbing grasses there was just enough remaining structure to suggest a floor plan of massive walls and simple square rooms. Here and there, close to the black lake of stars, were distorted metallic stumps which had once been parts of machines. They had a sagging, lava-flow appearance as though they had been destroyed by intense heat.

Kraemer gave a low whistle. “Who do you think won? The people who were trying to get in, or the ones who were trying to keep them out?”

“I’d say the invaders won, Lieutenant. I’ve been thinking about all those dead ships hanging out there. They can’t be in their battle stations because even if they had been stationary during the fight the forces used against them would have kicked them adrift and there would have been nothing for us to find. It looks as though they were rounded up and carefully parked just outside the aperture.”

“Why?”

“For salvage, perhaps. There may be no metals available within the sphere.”

“For beating into ploughshares? It’s good farming country, all right — but where are the farmers?”

“Nomads? Perhaps you don’t have to till the soil. Maybe you just keep moving for ever, following the seasons, with the grain always ripening just ahead of you.”

Kraemer laughed. “What seasons? It must always be high summer here — and high noon, too. It can’t even get dark with that sun right above your head.”

“But it is getting dark, Lieutenant.” Garamond spoke peacefully, all capacity for surprise exhausted. “Look over there.”

He pointed at the horizon beyond the black ellipse of the aperture to where the shimmering blue-greens of the distance had begun to deepen. There was an unmistakable gathering of shade.

“That’s impossible,” Kraemer protested. He looked up at the sun.“Oh, no!”

Garamond looked up and saw that the sun was no longer circular. It had one straight side, like a gold coin from which somebody had clipped a generous segment. Shouts from the other men indicated that they had noticed the event. While they watched, the still-brilliant area of the sun’s disc grew progressively smaller as though a shutter were being drawn across it. At the same time, keeping pace, the darkness increased on the corresponding horizon and a new phenomenon made itself apparent. The delicate ribbed effect which Garamond had noticed in the sky earlier became clearer, the alternating bands of lighter and darker blue now standing out vividly. In the space of a minute, as the sun began to disappear completely, the slim curving ribs became the dominant feature of the sky, swirling across it from two foci, sharply defined as the striations in polished agate. Near the horizon, where they dipped behind denser levels of air, the bands blurred and dispersed into a prismatic haze. The last searing sliver of sun vanished and Garamond glimpsed a wall of shadow rushing over the landscape towards him at orbital speed, then it was night, beneath a canopy of stratified sapphire. Garamond stayed beside the lake of stars for an hour before returning to his ship and sending a tachyonic signal to Starflight House.

eight

It was almost exactly four months later that Elizabeth Lindstrom’s flagship took up its station outside the sphere’s entrance.

Garamond had spent part of the time carrying out investigations into Orbitsville — the name for the sphere had originated with an unknown crew member — but, as it was primarily equipped for locate-and-report missions, the Bissendorf did not carry a large science team, and the studies were necessarily limited. The astronomy section, under Sammy Yamoto, made the most profound discovery of all — that there was yet another sphere surrounding Pengelly’s Star.

It was smaller than Orbitsville, non-material in nature yet capable of reflecting or deflecting the sun’s outpourings of light and heat. Yamoto described it as a ‘globular filigree of force fields’, a phrase of which he appeared inordinately proud, judging by the frequency with which it was used in his reports. Of the inner sphere’s surface area, precisely half was made up of narrow strips, effectively opaque, curving in a general north-south direction. Their function was to cast great moving bars of shadow on the grasslands of Orbitsville, producing the alternating periods of light and darkness, day and night, without which plant life could not survive. Yamoto was not able to observe the inner sphere directly, but he could chart its structure by studying the bands of light and darkness as they moved across the far side of Orbitsville, 320 million kilometres away in the ‘night’ sky. And he was able to show that the shadow sphere not only created night and day but was also responsible for a progression of seasons. In one quarter of the sphere, corresponding to winter, the opaque night-producing strips were wider and therefore separated by narrower gaps of light; at the opposite side the strips were reduced in width to engender the shorter nights and longer days of summer.

To facilitate Yamoto’s work a small plastic observatory was prefabricated in the Bissendorf’s workshops and transferred to a site within Orbitsville. Several more buildings were added as other sections found reason to prolong their work in the interior, and the nucleus of a scientific colony was formed.

A substantial portion of the effort was put into trying to solve the annoying riddle of why no radio communicator would work inside the sphere. At first it was anticipated that a simple solution and practical remedy would be found, but the weeks slipped by without any progress being made. It appeared that the equally inexplicable synthetic gravity field was responsible for damping out all electromagnetic radiation. In an effort to get new data on the possible mechanics of the phenomenon, O’Hagan’s team took a photographic torpedo and gave it enough extra thrust to enable it to take off from the inner surface of Orbitsville. The purpose of the experiment was to measure the gravity gradient and to see if the radio guidance and telemetry systems would operate if the signals were travelling at right angles to the surface. After a flawless programmed start, the torpedo began tracing random patterns in the sky and made a programmed automatic landing several kilometres away from the aperture. Pessimists began to predict that the only long-range communication possible on Orbitsville would be by modulation of light beams.

Another discovery was that the utterly inert and incredibly hard shell of the sphere was impervious to all radiation except gravity waves. The latter were able to pass through, otherwise the star system’s outer planet would have tangented off towards interstellar space, but not even the most energetic particles entered Orbitsville from the outer universe, except by means of the aperture. Certain peculiarities in the measurements of radiation levels from Pengelly’s Star itself led O’Hagan to give Garamond a confidential report in which he suggested that flickerwing ships might not be able to operate within the sphere, due to lack of available reaction mass. The subject was earmarked for priority investigation by the fully equipped teams which would arrive later.