Breach of Protocol
The ROU Negotiation Is Overrated was spun off the GSV Absolutely No You-Know-What with absolutely no ceremony whatsoever. Under happier circumstances, the departure of a daughter craft from a General Systems Vehicle was an excuse for a certain amount of celebration. Human and drone well-wishers would turn out to offer good fortune on the leaving ship and its crew; there would be fireworks and banners and balloons and an all-round party atmosphere.
The current emergency had put paid to such niceties; there was simply no time. There was effectively a queue to leave the ship. Both the GSV's Superlifters were in near-continuous operation, flinging craft after craft into the void on missions variously obscure, incompletely-specified, desperately urgent, changed at the last minute, and all the other effects of an unexpected and still not entirely fully-comprehended emergency.
The ROU slid out of its Bay then moved at high-subsonic speeds while still inside the GSV's innermost field structure - the one which retained the external atmosphere around the giant craft. It rendezvoused with the Cliff class Superlifter Greased Lightning. Together the twinned ships slipped through the outer fields and decelerated hard to a speed that the ROU’s engines could cope with unaided. There was a brief formal farewell, then the Superlifter powered away chasing the GSV, ready for the next dispatch operation.
"We've just left the Absolutely No You-Know-What," the voice of the Negotiation Is Overrated interjected, "It will take us about fifty hours to reach the Chaosarium."
Foklane Valbada stood and took a deep breath, then flexed her shoulders slowly.
"Thank you, ship," she said formally, adding, "No change of getting there any faster, then?"
"No chance," the ship replied, "I have no desire to compromise my engine field capabilities given where we’re heading. So, we're now on our own. To return to your previous question: we don’t know what is the importance of the Chaosarium. All we know for sure is that the Castophrenic Widowhood want the Culture to hand over complete control to them. It was part of the ultimatum."
"Surely we're not preventing anybody from visiting the Chaosarium?" Histoker insisted.
"We're not," the drone Formali-Kai said, "Indeed, there's been a continuous trickle of visits from a diverse collection of Involved and quite a few of the more determined Aspiring civs."
"We are, de facto, the unofficial curators of this particular alien artifact," the ship interjected, "But we've never been formally confirmed by the Galactic Council, or firmly refuted for that matter."
"So, if it's not our problem," Valbada asked, "Why don't we just abandon the thing, let the Widowhood know we're leaving it to them? One less reason to fight?"
"Two reasons, really," the ship replied immediately, "The first is that the Castophrenic Widowhood might be planning on destroying the Chaosarium - there's vague intelligence to this effect - although their rationale for that course of action is not clear. Perhaps they hope to learn something from it - although that seems unlikely, given the studies that so many others have undertaken. Or maybe they are afraid that the artifact will reveal to others some secret they already know."
"Deeply inscrutable," the drone muttered darkly, "But not really a reason for action."
"Perhaps not," the ship agreed, "Although some have argued to resist the destruction of such a unique artifact purely on moral grounds. Not to mention the potential loss of knowledge, should we ever really understand how the thing works."
"Not convinced," Formali-Kai said, its fields displaying the blue-grey aura of politely held-in-check frustration.
"The second reason, and the real reason why we are heading there as fast as I can reasonably manage," the ship went on, ignoring the drone, "Is that somebody else - one of the Involved, perhaps even some party within the Culture itself - is planning to deliberately disrupt an element of the Chaosarium."
"What?" Histoker shouted. Valbada glared at Formali-Kai, whose fields briefly flashed rainbow with surprise. She strongly suspected that there was suddenly a great deal of high-speed private communication going on between the ship and the drone.
"You've been keeping that one to yourself," Formali-Kai said after a moment, its fields returning to blue-grey.
The Culture had always been very careful to avoid accidentally influencing the motion of the Chaosarium. Ships had to keep a good distance away, and carefully null out the gravitational attraction from their significant mass using their fields; a million-tonne GCU or, still worse, a billion-tonne GSV would unquestionably affect objects as small as the whirling habitats. Probes and sensor platforms were designed to be as small and light as possible, and not assert any significant force as they moved about. And the Culture had always encouraged similar behaviour from other visitors, especially those whose ship-field technology was less sophisticated.
"Somebody? You said, somebody. You mean an actual person? Not a ship-Mind?" Valbada demanded.
"The intelligence - if I can apply the word to something as nebulous and, frankly, scrappy as the information we have gleaned - is unspecific," the ship replied, sounding exasperated, "So it could be anything - Mind, drone, human, alien - although there seems to be a connection to the Culture somehow."
"So that's our mission, then?" Histoker asked, now a little calmer, "To identify whoever or whatever it is that is planning on disrupting the Chaosarium, and stop them?"
"Not quite," the ship replied, sounding insufferably smug, "Let me tell you a story."
One of the techniques routinely employed by the Culture ships studying the Delphic Chaosarium was to model the chaotic system of moving, whirling habitats in order to predict their future positions. This kind of detailed simulation was of course child's play to an intellect as immensely powerful as a Mind - although, like a child at play, the ultimate result of any game was not infinitely predictable. When compared with the actual motions of the spheres, tiny differences between predictions and reality exploded exponentially as the time interval between the present and the predicted future grew.
In an attempt to compensate, sims developed by the Minds would be performed millions of times, each introducing an infinitesimal delta between point-in-time measurements of all the habitats' positions and speed, and the starting values in the simulation. Each simulation run would include a different delta; the nature of chaotic systems meant that the results of these different rounds would rapidly diverge over time, but at least they did tend to bracket the actual observed behaviour of the Chaosarium.
On one notable occasion, now some years in the past, all the multiple concurrent simulations seemed to converge on a single conclusion: that there would be a collision between two of the spheres. At first, the spread of possible outcomes was considerable: a head-on collision with enough force that might shatter either or both of the habitats in question; or just a glancing blow, a mere kiss which would send both objects off on slightly different trajectories. In any case, the sims definitely indicated that an intersection of the trajectories would occur.
As the predicted time of the collision grew closer - and the uncertainly over the precise nature of the impact became less - the behaviour of the Chaosarium was being studied extremely closely by the coterie of Minds and other intelligences - biological and otherwise - still gathered in the vicinity. Every sense and sensor available was at maximum sensitivity, attempting to identify any kind of corrective manoeuvre or collision-avoidance action performed by the mysterious spheres; or, to observe what happened after the smash.
Just when a glancing impact was thought to be inevitable, a wandering interstellar asteroid was spotted heading towards the Chaosarium at non-relativistic speed by some more-than-averagely paranoid GCU who had persisted in deploying its long-range scanners in random directions away from the immediate locale. It was a perfectly ordinary irregular piece of low-grade iron-ore spinning lazily around its own centre of gravity, a commonplace rock which had probably been thrown out of its original stellar system millions of years before.
There was no chance of a collision between the asteroid and any element of the Chaosarium but - much to the astonishment of the Minds when they re-ran their sims to take into account the proximity of the newly-spotted rock - there was sufficient gravitational attraction from several million tonnes of iron-rich asteroid to deflect several of the spheres just enough so that the previously-considered-inevitable crash was averted.
"And so the apparently-unavoidable impact never happened," the voice of the Negotiation Is Overrated concluded, "Through the unpredictable - at least, by us - appearance of a previously-unknown asteroid."
"So, the appearance of this unexpected rock was also predicted, some unimaginable length of time ago," Valbada said slowly.
"That's one interpretation. If true, then it would be a clear demonstration that the Delphic Chaosarium is in fact interacting with the rest of the universe - albeit very slightly, and over extremely long time intervals - and thus it might provide an insight into the future evolution of the galaxy and the societies therein."
"There's another interpretation?" Histoker demanded anxiously.
"Several," the ship replied, "But the one which is really worrying us is the possibility that there is something or someone out there who is actively interfering with the Chaosarium, guiding and shaping its behaviour in the most subtle and undetectable fashion."
"So our real mission," Formali-Kai said calmly, presumably having been briefed at length by the ship a few moments earlier, "Is to identify whatever agent out there is planning on experimenting with the music of the spheres, before they actually get to carry out their planned action, and observe things extremely closely to see exactly what the outcome might be."