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 urgent.

The Sleeper Service's acceleration figures remained steady at their design maxima for another twenty minutes, though the Charitable View — keeping a careful watch on every aspect of the GSV's performance from its station a few real-space light days behind — reported some odd events at the junctions of the Sleeper Service's traction fields with the energy grid.

By now the Yawning Angel was existing in a state of quiveringly ghastly tension; it was thinking at maximum capacity, worrying at full speed, suddenly and appallingly aware how long things took to happen; a human in the same state would have been clutching a churning stomach, tearing their hair out and gibbering incoherently.

Look at these humans! How could such glacial slowness even be called life? An age could pass, virtual empires rise and fall in the time they took to open their mouths to utter some new inanity!

Ships, even ships; they were restricted to speeds below the speed of sound in the bubble of air around the ship and the docks it was joined to. It reviewed how practicable it would be to just let the air go and move everything in vacuum. It made sense. Thankfully, it had already shifted all vulnerable pleasure craft out of the way and sealed and secured its unconnected hull apertures. It told the Hub what it was doing; the Hub objected because it was losing some of its air. The GSV dumped the air anyway. Everything started moving a little faster. The Hub screamed in protest but it ignored it.

Calm; calm; it had to remain calm. Stay focused, keep the most important objectives in mind.

A wave of what would have been nausea in a human swept through the Yawning Angel's Mind as a signal came in from the Charitable View. Now what?

Whatever it might have feared, this was worse.

The Sleeper Service's acceleration factor had started to increase. Almost at the same time, it had exceeded its normal maximum sustainable velocity.

Fascinated, appalled, terrified, the Yawning Angel listened to a running commentary on the other GSV's progress from its increasingly distant child, even as it started the sequence of actions and commands that would lead to its own near-instant departure. Twelve minutes early, but that couldn't be helped, and if people were pissed off, too bad.

Still increasing. Time to go. Disconnect. There.

The Charitable View signalled that the Sleeper Service's outermost field extent had shrunk to within a kilometre of naked-hull minima.

The Yawning Angel dropped away from the orbital, twisting and aiming and punching away into hyperspace only a few kilometres away from the world's undersurface, ignoring incandescent howls of protest from the Hub over such impolite and feasibly dangerous behaviour and the astonished — but slow, so slow — yelps from people who an instant earlier had been walking down a transit corridor towards a welcoming foyer in the GSV and now found themselves bumping into emergency seal-fields and staring at nothing but blackness and stars.

The superlifter's continuous report went on: the Sleeper Service's acceleration kept on increasing slowly but steadily, then it paused, dropping to zero; the craft's velocity remained constant. Could that be it? It was still catchable. Panic over?

Then the fleeing ship's velocity increased again; as did its rate of acceleration. Impossible!

The horrific thought which had briefly crossed the Yawning Angel's mind moments earlier settled down to stay with all the gruesome deliberation of a self-invited house guest.

It did the arithmetic.

Take a Plate class GSV's locomotive power output per cubic kilometre of engine. Add on sixteen cubic klicks of extra drive at that push-per-cube value… make that thirty-two at a time… and it matched the step in the Sleeper Service's acceleration it had just witnessed. General bays. Great grief, it had filled its General bays with engine.