“Size?” Wilson asked.
“The hole is seventeen kilometers across.”
“This wavelength doesn’t match Dyson Alpha’s known spectrum,” Tunde said. “That’s not the star shining out.”
Wilson couldn’t take his gaze off the sliver of light. “Any local activity that would indicate spacecraft or sensors?”
“No, sir.”
“I don’t suppose you know if that hole was open when we emerged from the wormhole?”
“We know the apex was flat, but the hysradar return doesn’t tell us if it was open.”
“Very well, recommendations?”
“Send a probe in,” Russell said immediately.
“Eventually, yes,” Tunde said. “But we’ll need to observe it for a while first.”
“While we’re doing that we could send a satellite on a flyby above the opening,” Oscar said. “Keep it at our current standoff distance, and take a look directly down inside. Our position gives us a lousy angle of view.”
Wilson was mildly surprised at the suggestion. He’d expected Oscar to be more cautious, although a satellite flyby was reasonable enough. If anything was in there, they must surely be aware of the Second Chance. “Go ahead.”
“I’ll start the prep sequence.” Oscar went over to the console Anna normally used, and called up the launch sequence.
“In the meantime,” Wilson said dryly, “does anyone have any ideas about what this thing is?”
Jean Douvoir chuckled softly. “Fortress of Darkness, where the evil lord hangs out.”
“Thanks. Anyone else?”
“I have a possibility,” Bruno said. He was close to blushing as the bridge crew all looked at him. “Well, it’s active, right? Something inside is generating gravity waves, and magnetic fields; and that’s just what we can detect. It’s also absolutely right on the equator; and as near as our sensors can tell, it’s perfectly aligned with the plane of the ecliptic. Though I’m not sure how relevant that is…” He glanced around, unnerved by the attention. “I just thought it might be a generator, that’s all, where the whole barrier is being produced from, or at least this area of it.”
Wilson looked at Tunde and raised an eyebrow in query.
“Gets my vote,” Tunde said. “Until something else comes along to disprove it.” He gave Bruno a thumbs-up. “Smart.”
Oscar launched the Moore-class satellite twenty minutes later. Its ion drive accelerated it away from the big starship, sending it curving over the apex of the dark hemisphere. Nearly every screen on board relayed the image from its visual spectrum cameras. The violet glow didn’t reveal much; certainly there was nothing lurking just inside. A very detailed analysis program picked up a slight but regular fluctuation to the output intensity. It didn’t match the oscillations of either the gravity waves or magnetic field.
Four hours after leaving Second Chance, the satellite was directly above the opening. Even on the highest magnification it could see nothing but the homogeneous dark blue glow, as if the hemisphere contained nothing but a fluorescent fog. Twenty minutes later, when half of the crew had lost interest, the light vanished, leaving the opening completely dark. Eighteen minutes later it reappeared.
Intensive slow-motion replays coupled with image enhancing programs showed that something had moved across the opening, cutting off the light.
“Your evil lord just blinked,” Oscar told Jean.
After three days of observation they knew the light was blocked on average every seven and a quarter hours, though this could vary by up to eight minutes. The eclipse duration was more constant, lasting a fraction over eighteen minutes, except once when it had gone on for nearly thirty-five.
As nothing had come out of the hole in all that time, Wilson finally authorized a close observation. A larger Galileo-class satellite left its launch bay on the Second Chance, equipped with a more expansive sensor suite than the Moore. Anna slowed its approach as it closed in on the hole, keeping it twenty kilometers above the hemisphere’s perfectly black surface. Telemetry showed her the little craft was taking a beating on the magnetic and electromagnetic wave fronts; even with circuitry hardened to withstand the kind of treacherous energy environment found around the most active gas giants she had to watch out for overloads and temporary glitches. Interference caused a lot of static within the datastream link back to the starship, resulting in poor imagery and broken instrument readings.
Everyone on board the starship watched as the hole slowly slipped into view, its gentle lavender radiance appearing like the dawn of a weak sun. It was an illusion that was broken soon enough as the satellite crept closer; the illuminated hole was small by any standards. Then the satellite passed over the rim, slowing to a relative halt. The magnetic flux in tandem with the gravity waves were strong enough to induce a detectable wobble, as if the satellite was floating on a sea. Anna did her best to counter the tiny vibrations, allowing the sensors to peer down carefully.
Four hundred kilometers below the hole, a curved lattice of immense dark strands were gliding slowly across the blue glow that came from deeper inside. As the satellite focused on the strands it became clear that the lattice was anything but a uniform hexagonal honeycomb. The interstices ranged from simple triangles up to twelve-sided grids with some of the strands curving them into near-ellipsoid geometries. The holes were the size of small countries, with strands up to a couple of hundred kilometers wide. One thing was obvious from the curvature and ponderous motion: the lattice was a sphere.
A thousand kilometers beneath it, a second lattice sphere was visible, also composed of dark strands, though this one had a more regular geography, mostly comprised of triangles and pentagons. It, too, was rotating, but in a completely different direction to the outer layer. And below that was a third lattice grid, with wider spacings. Its continent-long strands glowed a strong indigo, helping to create the pervasive glow. Its radiance was complemented to a large degree by streaks of amethyst light that came from underneath it, the indicators of a fourth lattice sphere spinning somewhere in the deeps. Exactly where was unclear; the third lattice appeared to be surrounded by some kind of lambent vapor.
“Son of a bitch,” Wilson whispered. Out of all the things he’d expected to see within the Dark Fortress, a kinetic sculpture bigger than planets was not high on the list. The scale of the barrier was already hammering at his beleaguered human senses. But that at least had been a projection, energy manipulated and folded on a stellar scale, while these lattice spheres looked resolutely solid. This was matter manipulated in quantities incomprehensible to Commonwealth technology. Yet the barrier creators had produced something that from a simple visual viewpoint was almost laughably mechanical, in the truest sense of the word. He wouldn’t be at all surprised now if they were to find gearboxes with cogwheels the size of moons driving the entire edifice. “Are those strands really solid?” he asked.
“I can’t tell,” Anna said. “The electromagnetic environment in there is playing hell with the satellite’s radar.”
“That much matter would coalesce under its own gravity,” Bruno said. “They have to be energy forms.”
“Not so,” Russell immediately claimed. “There’s nothing like a terrestrial planet mass in there. And their spin rates will keep them inflated.”
“Nonsense, they’d have to be metallic hydrogen to maintain their structural integrity under these conditions.”
“So? It’s metallic hydrogen. Apart from those glowing ones, I’d say they were exotic matter. There’s virtually no infrared emission coming from in there.”
“Is the outer shell complete?” Oscar asked. “I mean, is there a corresponding hemisphere on the inside of the barrier, or is this just some giant bearing groove for those lattice spheres?”
“Good question,” Tunde said. “Anna, can you focus the satellite telescope through those grids?”
“No, sir, no way,” she exclaimed. “That haze effect around the third sphere is like looking into a gas-giant cloudscape, and it gets thicker below it.”
“Like oil,” Oscar muttered. “It lubricates the gaps between the spheres.” He realized Tunde was looking at him and smiled an apology. “Just a thought.”
“Anna,” Wilson asked. “Will the satellite survive in there?”
She let out a long breath as she stared at the main image on the twin portals. “I don’t see why not, certainly as far down as the first lattice sphere, anyway. The sensor returns we’ve got show clear space that far in.”
“Okay then,” Wilson said slowly as a sense of real enthusiasm grew inside him. “Let’s do it.”
Anna launched a second Galileo-class satellite, flying it to the entrance hole at the top of what the crew now all called the Dark Fortress. Once it arrived, she sent the first satellite inside, using the second as a relay. As it descended toward the outermost lattice sphere, the energy surges around the satellite picked up noticeably. Eventually, Anna stopped trying to compensate. At that rate she would run out of fuel in a matter of hours. So she let the little craft wobble its way forward, blurring the visual sensor pictures. Every eighty kilometers or so she would stabilize it again, and run a quick check before allowing the vibrations to build up. There was nothing to see en route, the gap between the outer shell and the first grid sphere was empty, with the satellite sensors recording it as a hard vacuum.
When it was halfway there, one of the sphere’s massive struts slid underneath the hole, eclipsing the light pouring up from the inner lattice spheres. By now the crew were successfully recording the geography of the first lattice, and were making good progress charting the second. There seemed to be no logic behind the pattern. But predicting the times of the eclipses was now straightforward.
As the satellite grew nearer to the first lattice sphere, the radar return began to improve. “That’s odd,” Anna remarked as she stabilized the satellite once again.
“Problem?” Tunde asked.
“I’m using parallax to confirm the distance to the strut we’re heading for, but there’s a discrepancy between that and the radar return. Radar places it three klicks closer.”
“Maybe that optical haze effect is throwing the parallax reading?”
She shook her head. “Clear view. There is no haze around these struts.”
The discrepancy began to rise as the satellite closed in. Then they examined the magnetic flux around the strut, seeing the force lines warp like cyclone clouds around the surface.