parabolas. ‘That was just the start,’ Vuilleumier said. They showed him how the mass streams from the three dismantled moons converged on a single point in space. It was a point in the orbit of the system’s largest gas giant, and the giant planet would arrive at that point at exactly the same time as the three mass streams. ‘That was when our attention switched to the giant,’ Irena said. The Inhibitor machines were fearfully difficult to detect. It was only with the greatest of effort that she had managed to discern the presence of another smaller swarm of machines around the giant. For a long time they had done nothing but wait, poised for the arrival of the matter streams, the hundred billion billion tonnes of raw material. ‘I don’t understand,’ Thorn said. ‘There are plenty of moons around the gas giant itself. Why did they go to the trouble of dismantling moons elsewhere if they were going to be needed here?’ Those aren’t the right sort of moon,‘ Irina said. ’Most of the moons around the giant aren’t much more than ice balls, small rocky cores surrounded by frozen or liquid-state volatiles. They needed to rip apart metallic worlds, and that meant looking further afield.‘ ‘And now what are they going to do?’ ‘Make something else, it seems,’ Irina said. ‘Something bigger still. Something that needs one hundred billion billion tonnes of raw material.’ Thorn returned his attention to the eye. ‘When did this start? When did the matter streams reach Roc?’ ‘Three weeks ago. The thing — whatever it is — is beginning to take shape.’ Irena tapped at a bracelet around her wrist, causing the eye to zoom in on the giant’s immediate neighbourhood. Most of the planet remained in shadow. Above the one limb that was illuminated — an off-white crescent shot through with pale bars of ochre and fawn — something was suspended: a filamentary arc that must have been many thousands of kilometres from end to end. Irina zoomed in further, towards the middle of the arc. ‘It’s a solid object, so far as we can tell,’ Vuilleumier said. ‘An arc of a circle one hundred thousand kilometres in radius. It’s in an equatorial orbit around the planet, and the ends are growing.’ Irina zoomed in again, focusing on the precise midpoint of the growing arc. There was a swelling, little more than a lozenge-shaped smudge at the current resolution. She tapped more controls on the bracelet and the smudge bloomed into clarity, expanding to fill the entire display volume. ‘It was a moon in its own right,’ Irina said, ‘a ball of ice a few hundred kilometres from side to side. They circularised its orbit above the equator in a few days, without the moon breaking apart under the dynamic stresses. Then the machines built structures inside it, what we must assume to be additional processing equipment. One of the matter streams falls into the moon here , via this maw-shaped structure. We can’t speculate about what goes on inside, I’m afraid. All we know is that two tubular structures are emerging from either end of the moon, fore and aft of its orbital motion. On this scale they appear to be whiskers, but the tubes are actually fully fifteen kilometres in thickness. They currently extend seventy thousand kilometres either side of the moon, and are growing in length by a rate of around two hundred and eighty kilometres every hour.’ Irina nodded, noting Thorn’s evident incredulity. ‘Yes, that’s quite correct. What you see here has been achieved in the last ten standard days. We are dealing with an industrial capacity beyond anything in our experience, Thorn. Our machines can turn a small metal-rich asteroid into a starship in a few days, but even that would seem astonishingly slow by comparison with the Inhibitor processes.’ ‘Ten days to form that arc’ The hairs on the back of Thorn’s neck were standing up, to his embarrassment. ‘Do you think they’ll keep growing it until the ends meet?’ ‘It seems likely. If the ends are to form a ring, they’ll meet in a little under ninety days.’ ‘Three months! You’re right. We couldn’t do that. We never could; not even during the Belle Époque . Why, though? Why throw a ring around the gas giant?’ ‘We don’t know. Yet. There’s more, though.’ Irina nodded at the eye. ‘Shall we continue?’ ‘Show me,’ Thorn said. ‘I want to see it all.’ ‘You won’t like it.’ She showed him the rest, explaining how the three individual mass streams had followed near-ballistic trajectories from their points of origin, like chains of pebbles tossed in precise formation. But near the gas giant they were tightly orchestrated, steered and braked by machines too small to see. They were forced to curve sharply, aimed towards whichever constructional focus was their destination. One stream rained down into the maw of the moon that was extruding out the whiskers. The other two streams plunged into similar mawlike structures on two other moons, both of which had been lowered into orbits just above the cloud layer, well within the radius at which they should have been shattered by tidal forces. ‘What are the other two moons doing?’ Thorn asked. ‘Something else, it seems,’ Irina said. ‘Here, take a look. See if you can make more sense of it than we’ve been able to.’ It was difficult to surmise exactly what was going on. There was a whisker of material emerging from each of the two lower moons, ejected aft, against the direction of orbital motion. The whiskers appeared to be about the same size as the arc that was being built by the higher moon, but they each followed a sinuous snakelike curve that took them from a tangent to the orbital motion into the atmosphere itself, like great telegraph cables being reeled into the sea by a ship. Immediately behind the impact point of each tube was an eyelike wake of roiling and disturbed atmosphere many thousands of kilometres long. ‘They don’t come out again, as far as we can see,’ Vuilleumier said. ‘How fast are they being laid?’ ‘We can’t tell. There aren’t any reference points on the tubes themselves, so we can’t calculate how fast they’re emerging from the moons. There’s no way we can get a Doppler measurement, not without revealing our interest. But we know that the flux of matter falling into each of the three moons is about the same, and the tubes are all about the same width.’ ‘Then they’re probably being spooled into the atmosphere at the same speed as the arc is being formed, is that it? Two hundred and eighty kilometres per hour, or thereabouts.’ Thorn looked at the two women, searching their faces for clues. ‘Any ideas, then?’ ‘We can’t begin to guess,’ Irina said. ‘But you don’t think this is good news, do you?’ ‘No, Thorn, I don’t. My guess, frankly, is that whatever is taking place down there is part of something even larger.’ ‘And that something means we have to evacuate Resurgam?’ She nodded. ‘We still have time, Thorn. The outer arc won’t be finished for eighty days, but it seems very unlikely that anything catastrophic will happen immediately
