The door opens.

A young woman walks in, looks around, grins, and sticks her head back out. A few minutes later she and another young woman walk into the bar.

"Hello!" says the first one.

"Hello. I had wondered when someone else would come in; Bar says it's unusual for a single patron to be alone here for long. My name is Linyabel. Komarr, 2999."

"Komarr, that sounds familiar."

"Remember I told you last time I was here? The planet with the revolutionaries?"

"Oh, right, them. My sister's been running into a lot of people from your universe, it sounds like."

"Really? Well, they've either been very uninspired about making use of the opportunity or very good at covering their tracks."

"The first one inquired about taking home technology a bit more advanced than what they had for reverse-engineering after I told him I'd been doing that but Bar said anything obvious was too big for her to do."

"Uninspired," pronounces Linyabel. "Books are small and can be made smaller, if nothing else."

"I may have distracted him."

Snort.

"With conversation, Edie, about our respective worlds. Hi, I'm Emily and this is Edie, we're from Earth, 1986."

"Oh? Where on Earth?"

"At the moment, Westchester, New York."

"Are all Komarrans as...exceptional as you?"

"Oh, I'm not from Komarr. Eta Ceta, originally. And most of the time these days I live on Barrayar."

"...Eta Ceta. That's part of Cetaganda, right?"

"Yes. You stayed long enough for a nexusography lesson?"

"Not exactly! Why do I keep meeting people from this one family?"

"...You met members of my family?"

"The two other people I met here were Ivan and Mark, respectively."

"Ah. How is Mark?"

"Okay. Ish. About as well as could be expected, I think."

"Well, that's better than any expectable alternative, I suppose. And I imagine Ivan is well enough?"

"He was fine when I saw him."

"Good. At this rate perhaps you'll run into my husband. I can only imagine what he'd do with the place; I suppose it will depend on whether he finds it before or after I've told him about it."

"I imagine if I do it will go something like: 'Mark! So good to see you again!' 'Who on Earth are you?'"

"He's pretty unlikely to narrow it down as far as Earth if he doesn't know of the place, and if he does it will be because I told him about it, perhaps mentioning you."

"...Right. Thoughtless use of idiom, I suppose."

"A little. So you got along with Mark?"

"Yeah. He explained the circumstances of his existence and I summarized the ways my world is different from standard 1986 Earth and we both think Ivan is lovely."

"In rather different ways."

"That's how Ivan can tell the difference between Mark and Miles. Miles doesn't like Ivan quite that much and Mark can't fake it. I just bought a medical scanner."

"Peculiar."

...

"Shut up, Edie."

Linyabel blinks at Edie, who didn't say anything.

"Emily mentioned that our world was divergent from the standard 1986. I'm a telepath."

"A telepath who makes unhelpful comments."

"If you're asking if I can read minds, the answer is 'yes, but I don't on nonconsenting targets.' I haven't observed anything more of your mind than that it exists. If you're asking if I could do things to peoples' minds the answer is 'theoretically but I've never tried it,' because finding a consenting volunteer for that is neither trivial nor something I particularly care to pursue."

"That's good to hear."

"Uh-huh. Telepathy is one possible manifestation of a phenomenon that Ivan was particularly startled when I referred to it casually because we're called mutants."

"I hope he didn't offend you too badly."

"He eeped. He apologized for it later, which from what was later said was fantastic for someone raised on the infanticide planet."

"...It's not principally characterized by infanticide and if you meet Miles I don't recommend describing Barrayar that way, but yes, Ivan is between Miles and me positively enlightened compared to some people on Barrayar."

"He was...vaguely skeptical about some of it, but yeah."

"Skeptical that a mutation would produce a telepath? Well, I would be too, if I hadn't been talking to Bar for hours. I'm sure you're working on some kind of revised physics relative to our own, but that's bog-standard for Milliways, it seems."

"Skeptical that a mutation could produce someone who shoots plasma beams out of their eyes but the Cetagandans hadn't been able to do it on purpose."

"Well, he is not fully apprised of all the considerations that go into deciding exactly what the Cetagandans will and will not engineer, but there are engineers nearly so clever and much less restrained. Tetrachromats, of course. Winged people, yes - Cetagandans have done that, even, although it hasn't been rolled out into general use, interferes with other desiderata. Plasma eye beams - no."

"We have a few people who have wings."

"Which is genetically doable but absolutely preposterous as a single-step mutation - on my world. Not that I wouldn't be intensely curious to have a look at samples."

"Mutant's a bit of a misnomer. What we have is one gene that activates a lot of what would otherwise be junk DNA. It's recessive, so when you have two perfectly normal people who have a weird kid--it looks like a mutation."

"And yet humans have no ancestors with wings, nor plasma eye beams - on my world at least - so the junk DNA explanation also does not explain single-step wings."

"You're not wrong. For all I know we were genetically engineered by hyper advanced aliens or something, but we haven't seen any evidence of that in particular."

"Although I am a human, designed entirely by humans, I suspect I am hyper-advanced relative to your society - but still could not pull off plasma eye beams, not with a laboratory that was the stuff of dreams, not with anything short of 'copying it from somewhere'. Bar makes copying a more viable means of advancement than previously supposed, but still."

"This is all further complicated by the fact that when two mutants have children, the resulting offspring may have one of their parents' powers verbatim, or something similar to one or both, or something completely different."

"Given the existence of these powers - are they always only powers, never anything deleterious? - and the leading hypothesis involving junk DNA, that's not overwhelmingly surprising."

"Well, eye beam guy can't turn them off without technological assistance..."

"There are also miscellaneous physical alterations--our aunt has blue skin, for example."

"But no one who, oh, has their bones fused together or has no skin or anything like that?"

"Ew!"

"None that have come to our attention, but they usually don't come to our attention until they're old enough that having no skin probably would have killed them already."

"Oh, I didn't realize you weren't keeping comprehensive statistics. I suppose it's possible that truly deleterious mutations of this magnitude will be almost invariably fatal by the time you notice them if you're waiting for them to reach some age past five or so."

"We would like to but we're a private institution, not the government, and...there is no way that asking the government to try to keep comprehensive statistics on mutants is going to go well. If it's happened it hasn't happened often, anyway, we would have found out if it happened often."

"Which is itself surprising. Most changes are not improvements. But if you can get wings or telepathy in one step, maybe all the changes are so dramatic that anything unsafe causes spontaneous abortion? If not outright killing the carrier - how did the plasma eye beam one develop to term in a living person?"

"The living person has a mutation that lets them adapt to otherwise-fatal situations. They literally reconstituted themself after being disintegrated by similar plasma beams generated in a far less perilous fashion."

"Oh. I suppose that would help. So, all right, bizarrely coherent but perhaps high-variance anomalous traits, some of which cause miscarriage before anyone would notice them and some of which produce useful - powers. This sounds like an interesting world."

"Pretty interesting, yeah."

"I do bizarrely-controllable magnetism," Emily volunteers.

"Really? That sounds very versatile if you're creative enough and keep ferrous metal on hand."

Emily raises her arms; snakes of liquid metal pour out of her sleeves.

"That's amazing."

"I know! And I can fly by pushing myself off the Earth's magnetic field, it's great."

"Oh, that sounds like tremendous fun."

"It so incredibly is. I can't do it in Milliways, though, Milliways isn't on a planet and doesn't have the requisite magnetic fields."

"Alas."

"Totally worth it, though, Milliways has the previously mentioned reverse-engineerable technology and also beverages made of fruits that don't exist back home. Speaking of which, Bar? What would you recommend today?"

"Sure, yes please."

"Bar's recommendations are pretty much never wrong. Emily gets a different fruit thing pretty much every time she's here."

Bar supplies an Escobar pear nectar. Linyabel puts away the last couple bites of her meal and the dishes vanish. "I've enjoyed her expertise myself."

"If I didn't know better I'd suspect she was a telepath too, but even I can't do drink orders like that when someone gives me permission to read them."

"Well, like I said, I do know better."

"Mm-hm. So what exciting reverse-engineerable technology have you been bringing home to the nineteen hundreds?"

"Medical stuff, mostly."

"That's a good choice. I'm importing some of the same. Bar says that when Ivan was here she could not find Miles useful anaesthetic without knowing more about his medical properties, but I always carry," she pats a small object, "a medical scanner which has a recent scan of him, and I have his complete genome on my pen, so between the two it's only a little worse than if she had him here to look at, and I think he'll be delighted. He has the oddest allergies."

"My father can walk again."

"I'm so glad."

"We all are."

"In the case of many technologies Bar knows to exist the problem isn't that there's anything wrong with the technology but that the information that counts to her as 'published' isn't sufficient to reconstruct it from scratch. I wonder if you could use holo-pens where you're from, as long as I'm here to consult on them anyway?"

"I'd ask how they work but my brand-new degree is in education, not engineering."

"They're - computer technology has not advanced in the way that was promised in the nineteen hundreds and the two thousands," says Linyabel. "It's a cryptography and security problem, principally - I can't remember off the top of my head if you already have computers that are more portable than the average comconsole in my world, but you soon will, assuming a similar tech track. Our software is smarter, though, and I condensed the necessary cryptography and other equipment into this," she displays her pen, "which also does gesture recognition and three-dimensional holoprojection into the air. The simple model - low-security crypto that will still more than suffice against anything you're dealing with unless you have data mutants, cabochon-style nib, etcetera - you might be able to make yourself with a small handful of technological jumps I could help you get. But while the idea of using a turn-of-the-twenty-first-century portable computer fills me with dread I imagine it doesn't look like such a large jump coming from the other direction. So you might not consider it worth the trouble."

"...That sounds like the kind of thing it would be useful to have the plans for socked away in a database somewhere for when cryptography gets to the point it was when you invented them."

"Keeping up with the cryptanalysis is actually not the problem. The crytography keeps up. It just gets bigger. The real breakthrough was how I shrank it, and you'll have - Bar, an example of a relevant portable computer, late nineteen hundreds?" Bar shows them a laptop, presented open, and then vanishes it again. "You'll have those, which aren't as snazzy as my pens, but you also won't have the kinds of hacks that necessitated the arms race."

"Well, your pens are at least aesthetically interesting..."

"Thank you. I wanted mine to look like jewelry to a casual observer. They come in different colors, and Miles wanted one with a pointed tip - purest vanity and the hardest optics project I've ever pulled off, but they come with pointed tips now as an option."

"Vanity as cause for scientific breakthroughs. Well, I've heard of worse reasons."

"Well, he's very cute when he offers me engineering challenges."

"Aw, does he do that very often?"

"Not too frequently. I'm in a non-consumer-grade field at the moment - pens are down to occasional software upgrades and some delegated design, marketing, and fabrication work, not an ongoing concern in most of my working time."

"What field?"

"Neuroscience. I'm not the neuroscience expert in my operation, I hired someone, but I know enough to provide him software support and evaluate additions to the lab, and I'm picking up more."

"What are you trying to do with it?"

"Eventually? Uploading."

"Oooooh."

"It's a long way off. But pens make a lot of money and I am throwing it at the project as hard as I can."

"Sensible of you."

"We're hoping to find someone in Milliways with some kind of distributable immortality."

"Any luck? The haut have been trying to achieve biological immortality for centuries and have barely manged, well, 'centuries'."

"Not so far. Magic seems more likely than technology, though."

"Wouldn't that be nice. I'm planning to camp out in here for a few weeks at least, see what I can find. I'm certainly hoping for magic."

"We've met people with magic! Nothing we could take home, so far, but still magic."

"Oh? What kind?"

"Various. Some of them were single-task, more like the mutations from our world than the typical fantasy wizard, but some were more general. There was one who was some kind of dragon which came with several different kinds of species specific magic--like shapeshifting, which was how they could fit in the bar at all--and also a more generally practicable kind that only works in the world they're from."

"How disappointing that none of it was exportable. They sound interesting, at least."

"One of them might have been exportable--not everyone could do it even in the universe it came from, and we can't be sure that it wasn't just that we personally couldn't do it, not that no one from outside that universe could."

"If I find something like that, I'm waking up employees who can travel to my Komarr lab until I run out or someone can do it."

"The guy in question wasn't interested in hanging around long enough for us to oust the rest of the dorm. Maybe you would have been more persuasive."

"I'd probably have tried resorting to bribery. Bar can change currency."

"Fair enough."

"But she won't let me do arbitrage. It's very sad."

"How would you use Bar to do arbitrage if she let you?"

"Bar makes it trivial - if she'd let me. She can change currency, she doesn't take a cut, and she can do it between any economy and purchase back non-currency objects in adequate condition. If I buy a case of maple butter in Barrayaran marks at Vorkosigan hill district prices, and then sell it back for Zoavian credits at Twilight City prices, and then change those back into Barrayaran marks, I will have literally sixteen times what I started with, and that's just one of the first examples I thought of because I tend to tote Barrayaran maple butter around the galaxy. Bar can invent prices for objects in currencies from worlds that have never seen those objects, and it's largely her discretion whether she prices it as its theoretical value in that culture or just as an approximate translation of the buying power required to buy the object in its native location. There are no transaction costs, no shipping costs, and no difficulty obtaining pricing information. She can't handle particularly large volumes all at once, but she can perform trades almost instantly, and if I worked in small objects - selling aluminum to 1885 Earth, for instance - it would hardly matter. And yet. She is not allowed."

"But you're not actually transporting things between those economies, so wouldn't it basically amount to Bar giving you free money?"

"Yes. Which she can technically also do, if you're willing to run up a tab."

"Mm. Not quite the same thing, I think--there aren't any confirmed consequences to running up a tab, but there are suspected consequences, and a run-up tab is--definitely a thing, it's at least a guilt trip if nothing else."

"Yes. So arbitrage is a way to work around that, but the economic effect is still someone walking out of Milliways with more money that didn't strictly come from anywhere. But I wouldn't actually want to extract the fruits of my arbitrage in monetary form. From the perspective of the nexus economy that would just be uncontrolled inflation, albeit uncontrolled inflation more useful to me than most - and I'm still not sure what all this is going to look like on my First Galactic bank statement. I'd walk out with unsynthesizable elements or more gadgets of the sort I'm going to buy anyway."

"What I meant was more free value than free money per se, but I suppose I was unclear on that. But then in a way Bar gives out free value anyway, given the difference in cost between buying a gadget and taking it home and reverse-engineering it and funding the R&D work to develop it independently."

"Bar is lovely. And bound by seemingly arbitrary rules imposed by a mysterious outside force."

"I'm not sure they're arbitrary. They seem designed to prevent her from being too generous. A genuinely arbitrary rule would say she could sell anything but fudge and earmuffs and that she had to take half a subjective hour off if someone walked in from a place where it was Tuesday. Mysterious outside force, though, yes, I'm puzzled about that."

"Seemingly arbitrary in the sense that there isn't an obvious reason to prevent her from being generous."

"Yes. But it's oriented around something goal-shaped."

"Arbitrary and random aren't quite the same thing."

"As you like. Someone whose goal is to prevent Bar from being generous and can enforce that at all concerns me, and I'm only glad they aren't especially good at it. She confided in me that she will do small amounts of arbitrage for people who really need it; I simply don't qualify by any stretch of the imagination."

"Neither do we. All things considered I'm gladder than not."

"Oh, of course. It's a little curious that this is an exception to the rule that capital is the best tool for generating more."

Shrug.