Unsurprisingly, it was Asku Trashaw who reacted fastest. By the time the humans had spun around in a state of shock and confusion, the newcomer was already lit up by a dozen blue beams from the drone's mid-section.
"It's really not necessary to target me," the stranger said calmly, in unaccented Kurtursen, "Nor likely to be effective, for that matter."
At first glance, the stranger appeared to be a perfectly ordinary Xlephian garbed in the long flowing robes which were so popular here, with oiled hair tied in a topknot over a generically symmetrical face with the suggestion of facial hair above and below the mouth. Between the folds of the off-white fabric, the humans could just make out some coruscating kaleidoscope of colours: sometimes specularly metallic, sometimes the rich deep lustre of amber or jade or mother-of-pearl, and all - it seemed - glowing as if bathed in the flickering red light of some old-fashioned ironsmiths forge.
The blue beams flicked off, the drone apparently having decided there was no threat here it could counter.
"You're not human, are you?" Seich said carefully, somehow fascinated by the fireplace flicker.
"Not even slightly," Asku said, answering for the stranger, "Its internals are hot enough to melt lead and its metabolism seems to consist mostly of complex compounds of lanthanides and actinides - although at some eutectic point which means, I believe, that it's not quite a risk to boiling us all alive."
The figure snorted, giving every impression of mild amusement.
"I'm impressed by the sensitivity of your instrumentation," it replied, "Although it has to be said that I am making no attempt to disguise or otherwise hide my construction from you."
"What are you, then?" Olivero demanded, "And why are you here?"
The stranger smiled widely, disarmingly.
"I'm here to answer your questions, or at least Phage Rock's questions; the ones you have been sent here to find answers to."
"But you're not one of the Onlookers themselves, are you?" the Professor asked, narrowing his eyes.
"I am a synthetic entity - a machine, you would say, in the same way that Asku Trashaw here is a machine," it said, bowing fractionally in the direction of the drone, "But nevertheless I am a fully accredited representative of those who you know as the Onlookers."
"So, who are the Onlookers proper, then?"
"The Zihdren," the stranger intoned reverentially.
"Zihdren?" Olivero said, sounding perplexed.
"We, the Zihdren are an ancient vacuum-basker species," it replied, "Entirely space-based, evolved for hard radiation and the heat of the photospheres of stars. Hence the need for synthetic representatives in cold high-gravity environments like this."
Both Seich and Olivero's eyes widened. Neither of them had any idea that such species existed. The Professor nodded sagely.
"We have been a part of the greater galactic community for eons," the entity went on, "And there is a long-established tradition amongst the more advanced civilizations in the galaxy - the groups generally known as the Involved - about promoting the development of lesser species."
"Why?" Seich interjected, "To what end?"
"Well, partially, it's just charity, but there's another, rather more selfish reason," the representative admitted, "Civilizations come and go, in the Galaxy: grow indolent, die out, enter Retreats, Sublime or otherwise disappear from the everyday life of the Involved. Perhaps the Zihdren will follow one of these routes one day - although we have been around in the Real for longer than most - and it would be good to be remembered fondly by some species left behind."
The stranger appeared to take a deep breath, although its alien metabolism could not really have required such a thing.
"We have been guiding you, mentoring you for centeons - remotely, of course, and very discreetly - from before the time your precursor proto-sentient species emerged from the oceans or forests or savannas or jungles, and found it necessary to use intelligence and manual dexterity and social cohesion to survive in a hostile and unfamiliar environment."
"You've been breeding us?" Olivero demanded, sounding suddenly angry and stepping forward aggressively, "Creating us in your own image, remaking us to your own specifications?"
The representative held up both hands placatingly.
"No, no. There's no genetic meddling, no behavioural modifications. We want you to develop as close to naturally as possible. How could there be any originality, surprise, even amazement in your development if we guided you every step of the way?"
Olivero seemed mollified. He stepped away, flexing his hands to disperse the sudden tension he felt.
"Just the occasional hint, the gentlest of pushes," the stranger went on, adding calmly, "Even so, you are an experiment, a very profound one."
"What?" Olivero bellowed, spinning around.
"And entirely for your own benefit," the representative added, slightly hurriedly.
"How so?" Olivero demanded, glaring at the Zihdren machine under knotted brows.
"Usually, once a species makes its way into interstellar space or otherwise shows distinct signs of maturity, there is a stage of full and formal contact between the emerging civilization and their mentors. This usually leads to direct and prolonged collaboration between the two groups, often lasting for millennia. This process has clear advantages to the mentor civilization, but our hypothesis is that it sometimes dramatically stifles the development of the protégé species."
Seich nodded slowly; from the corner of her eye, she could see the Professor doing the same. From everything she knew about the nature of people - or at least humanoids - having a bunch of aliens who thought they knew better telling them what to do would be a recipe for either resentment or resignation. Even if the relationship was not quite tantamount to master and peon - and she personally convinced that unrestricted slavery of mentored species was entirely possible - no human she had ever met would perform at their best under these conditions.
"So we have been holding back from a full-on contact relationship," the Zihdren representative said, "Just passing minimal information to assist in technical improvements without - we thought - any inter-civilizational interactions, even hinting that we are no longer engaged in such contact."
"The Book of the Onlookers?" the Professor asked.
"Exactly so," the representative agreed, "But the idea of being alone in the galaxy is, according to our best analyses and projections, also decidedly an inhibitor to ambitious civilizational development."
Olivero and Seich glanced at each other. The interactions - of many and diverse kinds - between their two species had, she considered, been extraordinarily and almost universally positive for all concerned: not just at a personal level - she had never known a man quite as uninhibited and satisfying a lover as Olivero - but across all aspects of their several societies.
"So allowing us to discover others just like us," Olivero said, waving his hands to encompass Seich and Ngohan, "It is also part of the experiment?"
"Exactly so," the Onlooker said again, nodding, "In our experience, nothing like this has been tried before. The Culture's drive and ambitions are more likely to be fuelled by its mongrel nature, whatever species finally come together. Even we cannot reliably predict which ones will finally end up joining. But we have great hopes for the outcome."
Olivero held his head in his hands.
"This is big! Huge!" he said, sounding desperately confused.
"No doubt you are correct," the representative said, "You are not the first to have deduced the truth, nor will you be the last. But I would invite yourselves to consider carefully: do you want the Culture, as a whole, to know about all this? Or would you prefer this nascent society of yours to believe that the appearance of so many humanoid species in such a tiny volume is pure chance, entirely a coincidence?"
And then, without warning, the figure disappeared, with a soft pop and tiny flicker of light.
There was a silence, while the three humans tried to work out some kind of response.
"Can you keep a secret, Asku Trashaw?" the Professor asked, after a while.
"I can," the drone replied, "As long as nobody tries to read my mind."
"That would be very rude, wouldn't it?" Seich asked, sounding shocked.
"I think it would," Olivero said, "Surely nobody in the Culture would be so uncivilized to do such a thing."
Suddenly, the drone's body took on a soft rosy red glow.
"Asku Trashaw, you're glowing! Are you OK?" Seich demanded.
"Yes. Do you like it? The colour?" the drone replied, "It's supposed to indicate happiness."