The big GSV was already moving, rolling and twisting to point directly upwards out of the system. Its engine fields reconnected with the energy grid, its scanners were all already back on line and the rest of its multi-layered field complex was rapidly configuring itself for sustained deep-space travel.
It moved off, not especially quickly. Its Displacers had switched to pick rather than put now; in a matter of seconds they had snapped almost its entire fleet of smaller ships out of the system, their genuine yet deceptive delivery missions completed. Only the furthest, most massive vessels were left behind.
The Yawning Angel was already frantically making its own preparations to depart in pursuit, closing off most of its transit corridors, snap-Displacing drones from the Orbital, hurrying through a permission-to-depart request to the world's Hub and drawing up schedules for ferrying people back to the Orbital on smaller craft once it had got under way while at the same time bringing other personnel back before its own velocity grew too great.
It knew it was wasting its energy, but it signalled the Sleeper Service anyway. Meanwhile, it watched intently as the departing ship accelerated away.
The Yawning Angel was gauging, judging, calibrating.
It was looking for a figure, comparing an aspect of the reality that was the absconding craft with the abstraction that was a simple but crucial equation. If the Sleeper Service's velocity could at any point over time be described by a value greater than.54 x ns2, the Yawning Angel might be in trouble.
It might be in trouble anyway, but if the larger vessel was accelerating significantly quicker than its normal design parameters implied — allowing for the extra mass of the craft's extraneous environments — then that trouble started right now.
As it was, the Yawning Angel was relieved to see, the Sleeper Service was moving away at exactly that rate; the ship was still perfectly apprehendable, and even if the Yawning Angel waited for another day without doing anything it would still be able to track the larger craft with ease and catch up with it within two days. Still suspecting some sort of trick, the Yawning Angel started an observation routine throughout the system for unexpected Displacings of gigatonnes of water and gas-giant atmosphere; suddenly dumping all that extra volume and mass now would be one way the Sleeper Service could put on an extra burst of speed, even if it would still be significantly slower than the Yawning Angel.
The smaller GSV retransmitted its polite but insistent signal. Still no reply from the Sleeper Service. No surprise there then.
The Yawning Angel signalled to tell other Contact craft what was happening and sent one of its fastest ships — a Cliff class superlifter stationed in space outside the GSV's own fields for exactly this sort of eventuality — in pursuit of the escaping GSV, just so it would know this precocious, irksome action was being taken seriously.
Probably the Sleeper Service was simply being awkward rather than up to something more momentous, but the Yawning Angel couldn't ignore the fact the larger craft was abandoning a significant proportion of its smaller ships, and had resorted to Displacing people and animals. Displacing was — especially at such speed — inherently and unfinessably dangerous; the risk of something going horribly, terminally wrong was only about one in eighty million for any single Displacement event, but that was still enough to put the average, fussily perfectionist ship Mind off using the process for anything alive except in the direst of emergencies, and the Sleeper Service — assuming it had rid itself of its entire complement of souls — must have carried out thirty-thousand plus Displacements in a minute or less, nudging the odds up well into the sort of likelihood-of-fuck-up range any sane Mind would normally recoil from in utter horror. Even allowing for the Sleeper Service's Eccentricity, that did tend to indicate that there was something more than usually urgent or significant about its current actions.
The Yawning Angel looked up what was in effect an annoyance chart; it could leave right now — within a hundred seconds — and aggravate lots of people because they were on board itself instead of the Orbital, or vice-versa… or it could depart within twenty hours and leave everybody back where they ought to be, even if they were irritated at their plans being upset.
Compromise; it set an eight-hour departure time. Terminals in the shape of rings, pens, earrings, brooches, articles of clothing — and the in-built versions, neural laces — woke startled Culture personnel all over the Orbital and the wider system, insisting on relaying their urgent message. So much for keeping everybody happy with a week's leave…
The Sleeper Service accelerated smoothly away into the darkness, already well clear of the system. It began to Induct, flittering between inferior and superior hyperspace. Its apparent real-space velocity jumped almost instantly by a factor of exactly twenty-three. Again, the Yawning Angel was comforted to see, spot on. No unpleasant surprises. The superlifter Charitable View raced after the fleeing craft, its engines unstressed, energy expenditure throttled well back, also threading its way between the layers of four-dimensional space. The process had been compared to a flying fish zipping from water to air and back again, except that every second air-jump was into a layer of air beneath the water, not above it, which was where the analogy did rather break down.
The Yawning Angel was quickly customising thousands of carefully composed, exquisitely phrased apologies to its personnel and hosts. Its schedule of ship returns, varied to reflect the different courses the Sleeper Service might take if it didn't remain on its present heading, didn't look too problematic; it had delayed letting people venture far away until the Sleeper Service had sent most of its own fleet out, an action even it had thought over-cautious at the time but which now seemed almost prescient. It delegated part of its intellectual resources to drawing up a list of treats and blandishments with which to mollify its own people when they returned, and planned for a two-week return to Dreve, packed with festivities and celebrations, to say sorry when it was free of the obligation to follow this accursed machine and was able to draw up its own course schedule again.
The Charitable View reported that the Sleeper Service was still proceeding as could be expected.
The situation, it appeared, was in hand.
The Yawning Angel reviewed its own actions so far, and found them exemplary. This was all very vexing, but it was responding well, playing it by the book where possible and extemporising sensibly but with all due urgency where it had to. Good, good. It could well come out of this shining.
Three hours, twenty-six minutes and seventeen seconds after setting off, the General Systems Vehicle Sleeper Service reached its nominal Terminal Acceleration Point. This was where it ought to stop gaining speed, plump for one of the two hyperspatial volumes and just cruise along at a nice steady velocity.
It didn't. Instead it accelerated harder; that.54 figure zoomed quickly to.72, the Plate class's normal design maximum.
The Charitable View communicated this turn of events back to the Yawning Angel, which went into shock for about a millisecond.
It rechecked all its in-system ships, drones, sensors and external reports. There was no sign that the Sleeper Service had dumped its extra mass anywhere within range of the Yawning Angel's sensors.
Yet it was behaving as though it had. Where had it done it? Could it have secretly built longer-range Displacers? (No; half its mass would have been required to construct a Displacer capable of dumping so much volume beyond the range of the Yawning Angel's sensors, and that included all the extra mass it had taken on board over the years in the form of the extraneous environments in the first place… though — now that it was thinking in such outrageous terms — there was another, associated possibility that just might… but no; that couldn't be. There had been no intelligence, no hint… no, it didn't even want to think about that…)
The Yawning Angel rescheduled everything it had already arranged in a flurry of re-drafted apologies, pleas for understanding and truncated journeys. It halved the departure warning time it had given. Thirty-three minutes to departure, now. The situation, it tried to explain to everybody, was becoming more
