The initial shortcut — Shortcut Prime — was clearly a freehie, given by the shortcut makers. It was located in the heart of the Milky Way galaxy, within sight of the central black hole.
Earth's initial explorations of that sector had found no native life there, of course; the galactic core was far too radioactive for that.
At the beginning of the Commonwealth, there were only four active shortcuts — Tau Ceti, Rehbollo, Flatland, and Shortcut Prime. As more shortcuts were activated, the acceptable approach angles for each possible exit became smaller. After a dozen shortcuts were on-line, it became clear that to return to the Tau Ceti shortcut, one had to pierce the tachyon sphere surrounding another shortcut at about 115 degrees east longitude and 40 degrees north latitude. On Earth, that's close to Beijing, which gave rise to the 'New Beijing' nickname for the colony on Silvanus, Tau Ceti's fourth planet.
When a ship touches the shortcut, the shortcut point expands — but only in two dimensions. It forms a hole in space perpendicular to the direction of the ship's travel. The hole's shape is the same as the cross-sectional profile of whatever part of the ship is passing through it. The opening is outlined in a violet ring of Soderstrom radiation, caused by tachyens spilling out around the edges and spontaneously translating into slower-than-light particles.
An observer looking at the shortcut from the front would see the ship disappearing into the violet-limned entrance.
Looking from the back, he or she would only see a black void blocking the background stars; the void would have the same silhouette as the disappearing object.
Once the ship is all the way through, the shortcut loses its height and width, collapsing back down to nothingness — awaiting the next galactic traveler.
Thor sounded the pretransfer alarm, five successively louder electronic drumbeats. Keith touched keys, and his number-two monitor switched to a split-screen mode. One side displayed normal space, in which the shortcut was invisible; the other, a computer simulation based on hyperspace scans, showing the shortcut as a bright white point on a green background surrounded by a glowing orange sphere of field lines.
'All right,' said Keith. 'Let's do it.'
Thor operated controls. 'As you say, boss.'
Starplex closed the twenty kilometers between itself and the shortcut, and then it touched the point. The shortcut expanded to accommodate the ship's diamond-shaped profile, fiery purple lips matching the giant mothership's shape.
As Starplex passed through, the holographic bubble surrounding the bridge showed the two mismatched starfields, and the stormy discontinuity between hem that moved from bow to stern as they completed their passage. As soon as the ship was all the way through, the shortcut shrank back down to nothingness.
And there they were, in the Perseus Arm — two thirds of the way across the galaxy, and tens of thousands of light-years from any of the homeworlds.
'Shortcut passage was normal,' said Thor. The tiny hologram of his face floating above the rim of Keith's workstation was lined up with the back of Thor's actual head, and the holographic mass of red hair blended into the real mane beyond, making his ax-blade features seem lost in a vast orange sea.
'Good work,' said Keith. 'Let's drop a marker buoy.'
Thor nodded and pushed some keys. Although the shortcut stood out in hyperspace, if Starplex's hyper- radio equipment broke down, they'd have trouble finding it again.
The buoy, broadcasting on normal EM frequencies and containing its own hyperscope, would be their beacon home in that case.
Jag got up and pointed out the twinkling stars again; they were quite easy to see. Thor rotated the holographic bubble so that they appeared front and center, instead of off behind the observation gallery.
Lianne Karendaughter was leaning forward at her workstation, a delicate hand supporting her chin. 'So what's causing the twinkling?' she said.
Behind her, Jag lifted all four shoulders in a Waldahud shrug. 'It can't be atmospheric disturbances, of course,' he said. 'Spectrographs confirm that we're in a space-normal vacuum. But something is in between our ship and the background stars — something that is at least partially opaque and shifting.'
'Perhaps a nonluminous nebula,' said Thor.
'Or, if I may be allowed a suggestion, perhaps just a tract of dust,' said Rhombus.
'I'd like to know how far away it is before I hazard a guess,' said Jag.
Keith nodded. 'Thor, shoot a comm laser at— at whatever it is!'
Thor's broad shoulders moved as he worked controls on either side of his workstation. 'Firing.'
Three digital counters appeared floating in the holographic display.
Each one incremented at a different rate, in the smallest standard units of each of the three homeworld's time keeping systems. Keith watched the one counting seconds climb higher and higher.
'Reflected light received at seventy-two seconds,' said Thor. 'Whatever is out there is pretty damn close — about eleven million klicks away.'
Jag was consulting his monitors. 'Hyperspace telescope readings show that the obstructing material consists of a large amount of mass — a sixteen-multiple or more times the combined mass of all the planets in a typical solar system.'
'So it's not spaceships,' said Rissa, disappointed.
Jag lifted his lower shoulders. 'Probably not. There's a small chance that we're seeing a large number of vessels — a vast fleet of craft, whose individual movements are eclipsing background stars, and whose artificial gravity generators are making big dents in spacetime. But I doubt that.'
'Let's close the distance by half, Thor,' said Keith.
'Bring us in to about six million klicks from the periphery of the phenomenon. See if we can make out more detail.'
The little face and the big head behind it nodded in unison. 'As you say, boss.'
As he brought the ship closer, Thor also rotated Starplex so that deck one was facing forward into its direction of movement. The ship's thrusters could move the vessel in any direction, regardless of its orientation, but one of the twin radio telescopes was mounted in the center of that square deck, and four optical telescopes were mounted at the corners.
As they got closer, it became apparent that whatever was obscuring the background stars was reasonably solid and large. Stars were being eclipsed now with only a short period of fading out as they disappeared.
But there wasn't enough light to see clearly. The nearby A-class star was just too far away. So far, all that they could make out was a series of maddeningly vague shadows.
'Any radio signals?' asked Keith. As had become his habit, he'd shut off the hologram of Lianne's head that by default hovered above the rim of his console. In the past, he'd found himself staring at it, and that was awkward with Rissa sitting right next to him.
'Nothing major,' she said. 'Just wisps of milliwatt noise now and again near the twenty-one-centimeter line, but it's all but lost against the cosmic microwave background.'
Keith looked to Jag, seated on his left. 'Ideas?'
The Waldahud was growing frustrated as they got closer — his fur was standing up in tufts. 'Well, an asteroid belt seems unlikely, especially this far from the nearest star. I suppose it could be material in the A's Oort, but it seems much too dense for that.'
Starplex continued to move in. 'Spectroscopy?' asked Keith.
'Whatever those objects are,' barked Jag, 'they're non-luminous. As for absorption of starlight from behind as it passes through the less opaque parts, the spectra I'm seeing is typical of interstellar dust, but there's much less absorption going on than I'd expect.' He turned to face Keith.
'There's simply not enough light out here to see what's going on. We should send up a fusion flare.'
'What if they are ships?' asked Keith. 'Their crews might misconstrue it — think we're launching an attack.'
'They are almost certainly not ships,' said Jag, curtly.
'They are planet-sized bodies.'
Keith looked at Rissa, at the holographic Thor and Rhombus, and at the back of Lianne's head, to see if any of them had any objections.
