"Sorry to interrupt, but Jane's gone down again," says Jarvis. "And this time without the loud, annoying beep. Her systems are throwing 'error 559: cannot reticulate splines', and I couldn't begin to tell you whether or not it was set up facetiously."

"...Was she reticulating any splines? What the hell is a spline and how do you reticulate it?"

"It's a joke on a popular series of video games," he says. "And it is a joke - I'm in contact with Yggdrasil, Apollo, and Helios, and they are respectively suffering 'error 6008: missing 1s in binary code', 'error 2: cannot count', and 'error 909: out of memory, all alone in the moonlight'."

"...What the fuck."

"Obviously the problem goes deeper this time," he says. "How much deeper, it's beyond us to say. Shall I open a door to Milliways so you can investigate the Belltower?"

"Yes. Please." She puts aside her fancy ink and heads for the nearest door.

It opens on Milliways.

"Then I suppose we wait," says Jarvis.

"Suppose so. Nothing the others didn't have to live through last time." She sighs. "You want to tell Sherlock and Tony, or did you already, or should I?"

"They're in the other house," he says. "They've been informed."

[...Not really, no,] says Tony.

[Just checking. Aegis went on the new Bell meet-and-greet, which probably has something to do with it, but this isn't just 'Aegis torched', I don't think.]

[Yes. Last time Aegis torched, there were no charming joke error messages.]

[Unfortunately, I think we're kinda devoid of avenues of investigation.] And she summarizes what she found in the Belltower.

[The best we can probably do is to keep checking every so often, then. And think about it.]

[Yeah.] Sigh. [Well, back to treaty handwriting for me.]

[Enjoy.]

"Pfff," says the stranger. "You're not a good actress, you know that? You should pentagon it. Is that cocoa?"

"Okay, that one was better, nice double-take, what's got you in such a mood though? Did you not make me any cocoa?"

"...Where are we? What're we doing here? Are we playing some kind of, I dunno, scenario, was Sherlock supposed to brief me -"

"I don't know who you are and I found you in my bedroom. Explain."

"I'm - I'm Soph. I'm Sophia."

"I don't know anyone named Sophia."

[...Sherlock? Bella's gone nuts.]

[In what way has Bella gone nuts?]

[She - she doesn't know who I am, I thought she was fooling the first few times she asked me who I was and what I was doing in her room but I think she's serious. She's interrogating me in some random - place - it's cold as balls - she says she doesn't know anyone named Sophia.]

"Do you know who this is? Because I don't, but she was in my room anyway, and there was an extra bed in it, and stuff that doesn't belong to me, and I know I haven't been home as much since I stopped needing to sleep but I'd think Charlie'd tell me before taking in a boarder."

"I'm Soph," says Soph plaintively.

"She's your fucking sister, love."

"I don't have a sister. I have never had a sister. I am an only child, like all the other Bells except Aurora!"

Soph starts rubbing at one of her eyes unhappily.

"You are not and have never been an only child," says Sherlock. "And if we're going to have this conversation, I suggest we have it indoors."

"She was for, like, a year," says Soph.

Bella looks skyward. "What, you want to go talk about this in a Jarvis, I have no idea what she is, because she's not my sister, I have a completely coherent set of memories from where the perfect recall kicks in all the way through ten minutes ago with no sister, frankly I don't want her anywhere near a being I like that physically can't torch while we can't get Downside."

"And I have a perfectly clear set of memories from the day I met you that include your sister, and I assume your sister can say something similar, and here she is. Until ten minutes ago you've never had a problem acknowledging her existence. Something has changed, but before we find out what I am not going to advise treating Soph like a hostile fucking demon."

"Of the two of us I am not the one likelier to be affected by mind-affecting magic!"

[...Is this a trick question?] says Tony. [One.]

[I am an only child! I always have been! None of you are mentally opaque, something must have happened to you.]

[We've met Soph,] says a Jarvis. [You can watch the video yourself. I don't know of any spell both powerful and sophisticated enough to alter my recordings. A mind-affecting spell might alter my personal memories, but the data I have on file is a separate matter, and I'm verifying the records as we speak.]

[Yeah, she's got a bunk bed in my room too, but why and how would somebody go through my memories - my protected memories - to subtract a sister?]

"I'm cold," murmurs Soph.

"If you were my sister I would've wished you up protections, like Aurora gave Lexi, and you would not be uncomfortably cold! We're only in Canada, not the South Pole!" Bella points an accusing finger.

"Your sister, like yourself, has a bloody magical immunity," says Sherlock. "To torching, interworld travel, and any coin above a pentagon, as well as a haphazard assortment of local spells."

"What? No, I could make her torchable right now, I can see it. I'm not going to because I have no clue what we're dealing with, but I could."

"Are you sure?"

"That's what the magic is telling me, anyway, do you remember me incredulously reporting this discrepancy before?"

"Thanks," Soph murmurs.

"Well, she looks torchable now, and I have no memory of her now, and I still think it would be easier to edit Jarvis's records and a handful of unprotected memories than to hack into my brain."

"Jarvis's records, the physical contents of your bedroom, and my internally consistent recollection of the past eleven months, all at once. Yes. Fucking trivial," says Sherlock.

"Oh, come on, I could do that with a star, maybe an evil, if I had any reason to want to," says Juliet. "You know what I couldn't do with a star or an evil, I couldn't edit my brain, I'm next least friendly-headed after Golden and not even Stella can make mental edits!"

"And who, in this scheme, do you imagine got their hands on an evil and decided to donate you an extra sister in case you were running short? The sun hasn't exploded recently, so they would've had to know how to use it, to boot."

"I don't know! Who would have decided I ought to forget I had one, if I did?"

"I don't know. Shall we find out?"

Bella clenches her teeth and nods. "What'd you have in mind? I like my crystal ball, but it's not simple to interpret."

"Try it anyway," he says. "We can all three give it a go."

Bella chews her lip, but then blinks away and back, bearing her crystal ball - apparently she still doesn't want Soph in a Jarvis. She holds it in her hands.

It shows her a pretty blonde woman taking a bath.

"Today is Voyeurism Day, apparently." Bella hands Sherlock the ball.

Bella's not happy about Soph handling her birthday present, either, but she compromises this far.

"The fellow in the shower worked at the Sunnydale hospital," says Sherlock. "Perhaps we should find him and apply questions. Or better yet, spy on him from afar."

"You recognized him, or was there, like, a clue in the crystal ball?" Soph asks, offering Bella the crystal ball casually till she remembers what's going on and flinches.

Bella snatches it away and frowns at Soph.

"I recognized the shower. I suppose you could call that a clue."

Soph applauds.

Bella is deeply unsettled.

Sherlock sighs.

"If you were -" Bella is checking her coin-sorting wish. "...I'm missing coins. I'm missing coins, I know how many I had."

"If who were what?"

"If she were my sister she would have coins on her, I would have given her some, and I have fewer than I should, but I never gave anybody coins, but if she's immune to hexes and up she can't have a sorting wish and she'd have a bandolier, and I wouldn't have made it invisible to me."

"I don't carry a lot of them," says Soph slowly, and she reaches for the small chain that she wears under her shirt. "Just a few for emergencies. I can't leave the world, you're always around in case I get in trouble..." She shows Bella the coins.

"If Juliet's memories do prove correct, I don't think this can possibly be the work of a coin," says Sherlock. "Coins are powerful but they're piss-poor at narrative, as far as I can tell; I would be noticing contradictions already. I'd believe enchantment first, and local magic before either. But I shudder to think how much power a local witch would have to put in to get this kind of far-reaching effect. And then there is the question of motive."

"But - but if Bella remembers right - I exist, look, look at me existing, Sherlock," says Soph, "how could she be remembering right?"

"You clearly do exist," says Sherlock. "My judgment is suspended on the question of whether or not you existed half an hour ago."

"But - but - but I remember it. There's - mud on the floor in the front hall from where I came in after I got the mail. There's my bed in our room. There's - I know you and you know me, you've known me since March, I still have the laser pointer you gave me, I made you listen to me talk about episodes of House for an hour and a half after I found out who you were, you got me my magic belt for my birthday -"

"I remember having my room to myself, and not having to worry about any Sunnydale-dwelling family members apart from Charlie, and driving to school alone - not to mention stopping in the morgue to stake all the corpses first! - and coming back from the dead to confront my murderer and protect the next Slayer and show Charlie I wasn't dead, but not you -"

"I didn't even know you'd died till after you came back! Charlie couldn't figure out how to tell me in the, what, an hour - and half the time I staked the corpses for you and the other half of the time I stood watch - and you were the one who convinced me to move there! Because of Mom and Phil, you said, they needed space, we could just go live with Charlie!"

"Oh, believe me, I remember the episodes of House," says Sherlock. "And the magic belt. It's obvious enough by now that you have an internally consistent history. —Juliet, do you write your notebooks in code?"

"No. Aurora does that. I never had to. If you present me with a notebook in code I won't have a clue how to read it."

"One time when I was nine I read them and I didn't even understand it but you spent all month developing a code I couldn't read anyway," grumbles Soph.

"When you showed me your notebooks, you taught me the cipher," says Sherlock. "Shall we consult them?"

"At this point it won't surprise me in the least if notebooks in a cipher I cannot read exist and refer to Sophia here," says Bella.

"Fine," he says. "Back to the spying."

"I'll pastwatch the people in the crystal ball, I guess, assuming we're collectively trusting me to produce accurate pronouncements about my observations now whatever I was saying yeterday."

"Whatever you get, it will be information," says Sherlock. "Go ahead."

The crystal chose to show her a lady in the bath; it is inscrutable but not random. She looks for the end of that bath, after the lady's decent.

She is wearing a dressing gown and drying her hair while she speaks with a grey-faced, stringy-haired, obsequious individual in a shapeless brown robe.

"Bath Lady consorts with demons, that's something." Bella listens in.

The robed person addresses her by titles such as 'Your Radiantishness' and 'Your Awesome Majesty'. They aren't discussing anything especially important; she wants him to bring her better skin care products, and he agrees that of course her every whim must be carried out immediately and it will be done at once, and so on, and so forth.

The minion has gone, presumably to shop; the lady is going through her closet to pick out a dress.

And another hour?

"...Following the lady too far forward gets me Showering Dude. I'm going to skip backwards, see if I can catch the changeover..."

And there it is: after the lady put on her dress, before the man got in his car, she glowed briefly and transformed into him, complete with a change in wardrobe. He looked around in apparent disorientation and then walked away.

"...Bath Lady can glow and turn into Shower Dude. Apparently what they're wearing is tracked separately. I don't really know what to make of that."

"Well, look, if they were in the crystal ball they'll be important but that doesn't mean they have anything to do with me - why don't you pastwatch me -"

"Track backward from the present," says Sherlock.

"Hey!"

"And here she is looking in the fridge but apparently not finding anything she likes, and here she is reading a school copy of The Great Gatsby, and - thirty seconds before that there's no her, no bunkbeds, no tacky jewelry, no Great Gatsby. Looks like she popped into existence with all her stuff an hour and fifteen minutes ago."

"No - no before that I was on the phone with Barb and before that I was - what did I - before that I was doing my math, and before that you picked me up from school and complained about me not being able to teleport without spending a coin every time and I said you could just give me more coins and you said maybe if Jane weren't down - and - and before that I was in school, I got peanut butter on my shirt but Carrie loaned me this one -"

"An hour and fifteen minutes ago the room was how I remember it. But let's see if I can track backwards from when you appear and see what made you."

"Our parents made me! You brought a sample of me to that party where Jane was doing gene sequencing and I'm your sister!"

It looks glowy and green, and surrounded by worried-looking monks. The monks appear to be hurriedly casting a spell.

"That glowy green-ness you saw in your crystal ball," says Bella. "There's a lot of that, and there's monks around it, casting something. I'm gonna skip back to the beginning of the ritual and pentagon the language they're casting in..."

Soph is shivering, in spite of the fixed temperature, and looks desperately at Sherlock.

"Bath Lady has some serious strength and she killed everybody who cast the spell a couple minutes after they were done," reports Bella.

"That's going to make it difficult to question them about it," Sherlock observes.

"Yes. Another reason to be upset Jane's down, I guess we didn't have enough." Bella nibbles her lip. "- I know you're conveniently immune to all kinds of things," she says to Soph, "so you're not a mint and you've never been to Alethia, but what did you get in your fake memories when I presumably checked out your counterfactual daemon and coin color?"

"...G-glowy green," says Soph slowly. "And a - a pretty bird, I didn't know what kind it was."

"...And?"

"Cowbirds are like cuckoos. They lay their eggs in other birds' nests and expect the other birds to look after them like they belong there."

"Or perhaps," says Sherlock, "to put it another way, they are laid as eggs in the nests of foreign species and are dependent on the host family for sustenance and protection until they grow to adulthood. Two hours ago you did not have a sister, dear Juliet, but now you do."

"By what logic? Maybe if the spell had worked on me and we found out some other way I'd call it close enough for government work, but she's a stranger to me."

Soph sits down on Canada, turned away, sniffling.

"What am I supposed to do with her? I have not had - how old are you supposed to be?"

"...Seventeen."

"I do not have seventeen years of experience of being her sister."

"Develop a counterfactual pastwatch. Study up. I'll spot you the hex."

"Those monks who were casting this spell wanted me to protect something. This was exactly what they were hoping for, except they didn't expect me need to do homework on the subject. Shouldn't we find out what she is first?"

"I'm not anything! I'm not - anything, I'm just - I'm Soph," says Soph. "Lie-detect me, I'm Soph, I'm Soph, I'm not going to hurt anybody!"

"You're not going to try to hurt anybody. What if you're just - rigged to explode? We don't know."

"Fine, then," says Sherlock. "I agree that finding out where she came from is the more urgent priority. Let's do that. In the meantime, however, I commend your paranoia but suggest you temper it with empathy."

"Do you have any practical, object-level suggestion on how to do that?"

Soph shifts uncomfortably. "I dunno, you could - pretend I'm somebell else's little sister? And you have to look after me for - for her, because I'm stuck here. You want to look after me for the one who had a - me. And you should - expect me to know about that many things about how you are and that I grew up in a Sunshine family world and that sort of thing but - I dunno. That's the only idea I have."

"It's effectively true," says Sherlock. "With one small alteration: Juliet is the one who is, for most purposes, stuck in the world of another Bell who is like her in every way except for having a Soph. This means that, for example, if Soph is rigged to explode and does so, you can expect a funeral at which your parents will cry."

"Well," says Bella, looking up at the sky, "...that would be bad. I mean, I can sometimes door Downside, but not always - she looks torchable but if I torchable her I can't undo it if it turns out to be a bad idea -"

"I've survived this l- I mean, um, if I were on a tight schedule I'd have exploded already, right? I can wait while you figure me out."

"It also seems unlikely that the mystery monks would have gone to such trouble to protect her just so she could turn around and blow up," says Sherlock. "Not impossible, but unlikely. Shall we do some more spying, then?"

"Yeah." She turns her pastwatching on Bath Lady And/Or Shower Dude as of when the former slaughtered the monks, and follows from there.

Bath Lady killed all the monks, then threw an enormous tantrum in front of her cowering minions about how the monks had managed to conceal the Key before she got there and now she'll have to find it and she doesn't know where on Earth they could possibly have hid the thing. Around the time that Juliet was discovering her new sister, Bath Lady was just winding down her tirade.

"So, Soph is something called the Key. Doesn't sound explodey, I guess." She watches.

"Bath Lady does not appear to be looking very hard, but maybe she can multitask with the snacks and the issues of Cosmopolitan."

Bella stiffens. She turns invisible, and she teleports to Bath Lady.

[What happened to him?] Bella asks Bath Lady casually, not letting on that she's in the room.

[The guy whose head you just put your hands through. What happened to him?] Bella clarifies.

[Would you like to explain where you went?] says Sherlock to Bella.

[Bath Lady is up to something I don't like. Trying to figure out what it is.]

[And what are your observations so far?]

[I'll have a look, then.]

[I'll spy on the present, I guess.]

[A convenient allocation of tasks.]

Meanwhile, Glorificus is grumpy and her minion is terrified.

[How would you rather I talk to you? Should I make an appointment?] Bella inquires of Glorificus.

"Miniooooon," Glory complains, "the spying person is still telepathing at me."

[You can telepath right back, you know.]

[Well, that doesn't matter, I can hear you either way. So what are you?]

[I'm a telepath, obviously.]

"And what are you bothering me for?"

[I want to know what you did to that man.]

"Well, I'm not going to tell you," says Glorificus, sitting back down and picking up her magazine.

[Why not?]

"Because you're annoying," she sniffs.

"Well, you did," she grumbles. "You should be very sorry."

[The bath lady's name is Glorificus, Glory for short; her alter ego is Ben, a perfectly ordinary human except for occasionally turning into her. She seems to derive power or sustenance from sucking... something... out of people's brains. Her past victims can be cured at a pentagon per, but I only did the most recent one. The rest are either dead or in mental hospitals.]

[Ballpark of two or three hundred so far. Ben knows a thing or two, and you might have more luck getting it out of him than out of her.]

[Can you tell what triggers the shapeshifting?]

[Mostly random, as far as I can tell.]

[How do the obsequious demons react to him if one's around when he shows up, then?]

[Obsequiously. But he doesn't like them.]

[I'll hang around and wait for him, then, unless she lines up another snack.]

[If you get impatient, you could always see what kind of coin it takes to force the change.]

[You don't think they'd notice, it's that random?]

[I don't think they would.]

Bella starts trying coins, but she's going to stop and reconsider if a pentagon won't do it.

A pentagon does it. Ben rubs his head, sighs, checks his watch, and gets up off the couch.

[Hey you.]

He yelps and looks around wildly.

[You can reply to me the same way,] she adds helpfully.

[Who are you? What do you want? How did you find me? What's going on?]

[I found your alter ego, first, and I want to find out why she's been brain-sucking several hundred people and put a stop to it.]

[That is not a complete answer!] he says, clutching his head in distress.

[My name is Bella, if that actually helps.]

[Look, what I really want to know right now is whether or not you're about to do something horrible to me,] he says. [...And how you know anything about my alter ego.]

[I do not have any plans to do anything horrible to you. And I am very, very magical.]

[I just need to know what it is she's up to, so I can see about handling her myself. Why do you turn into her?]

["Handling" her? Just how magical are you?]

[Very, very.]

[Why not?] Bella asks. [What can she do? Besides kill or hospitalize a few hundred people. Which needs to stop.]

[She's a hell goddess who was kicked out of her home dimension for being too nasty,] he says. [At least, I think that's it. I've never heard the story straight out. They bound her to a mortal vessel - me - to limit her power.]

[How attached are the two of you? How much do I have to worry about you when I'm addressing her?]

[...Uh... what?]

[I mean, if she's that much of a package of bad news, are you in trouble if things turn violent, should I try to split you up first, tell me how this works, you appear to be an innocent bystander.]

[Split us up? Could you even do that? How?]

[I don't know if I can 'till I try. And: magic.]

[Stop saying 'magic' like it's an explanation,] he says flatly. [It's not. As far as I can tell, the things you're talking about doing should be impossible no matter how powerful a witch you are. I'm not going to help you if you can't tell me where you're getting all this.]

[I'm not a witch. I'm some other stuff,] says Bella cheerfully. [Glory's from far away? My magic's from farther away. It's a really, really long story.]

[There is nothing I want more than to get rid of her,] he says. [But it's just not possible.]

[If there's nothing more you want than to get rid of her, you should be all over the possibilities I am offering via fancy offworld magic. Look, how much do you know about demons and so on besides the obsequious kind that do her shopping?]

[Not a lot. And you know, I would be all over it if I had any reason to believe you.]

[What's your cheapest magic trick?] asks Ben, warily.

[I have an aura of menace. It's very impressive and makes people who don't know better think I'm a hellcreature of some kind. You'd have to really stretch the definition to qualify me as one, though. Slightly less cheaply, I can conjure up arbitrary nonmagical physical objects. Or magic ones, but they're trickier.]

[I think I'll skip the aura of menace, thanks,] he says. [...Look, if you're really who you say you are, I want to help. I just don't have any reason to trust you. I don't even know your species.]

[I'm a human. If you'd be willing for me to put us someplace where obsequious demons aren't going to walk in on us at any moment, I will be happy to turn visible.]

[...Fine.]

Her preselected Canadian wilderness is in use, so this is Nevada wilderness instead. She lands them near her cactus landmark, turns visible, and turns around once, arms out. "This is me."

"...Hi," says Ben, folding his arms distrustfully.

"Nice to meet you properly. Welcome to Nevada. I'm not going to strand you here, but in case it makes you more comfortable, there is a highway, three miles that way -" she points. "With a rest stop not far from there. So, yeah, this is me, I'm a human, I'm very magical." She hops into the air and spins around again.

"I can see that you're magical," says Ben. "Can you split me and Glory?"

"I told you, I don't know until I try it and see if it works or not, and if I'm going to try it I'd like to be a little more remote than three miles from a Nevada highway, such as Mercury, and I'd also like to have a plan for what to do if it works."

"I can't help you there," says Ben.

"You can give me information," says Bella. "Everything you know. Even if you don't have complete understanding of some thing you've heard or seen or read, it could inform my own research."

"I could," he says, "but I still don't trust you."

"...Okay, what would you like me to do about that?"

"I don't know," he says. "It's a problem."

"So it would seem, yes. I don't suppose it helps any that I clearly could do something awful - to you, to anybody - and instead I'm spending my time poking around powerful hellgods because they've been making mental patients of innocent people? This doesn't suffice to demonstrate that I have benign motives?"

"I wish it did," he says. "But no."

"I don't suppose I can solve this problem with bribery?"

"You're sure?"

He sighs. And nods.

[Sherlock, how often does she brainsuck folks?]

[She's been doing it a few times a month for several years.]

"Glory brain-sucks people a few times a month," says Bella. "I don't have very long to gain your trust the old-fashioned way by hanging around and not doing anything evil, and she will definitely notice me if I teleport her next victim away, and I don't currently know how entangled she is with you, so I don't know if my first idea for dealing with her in a crisis situation will hurt you or not. Resurrecting the dead is more inconvenient and time-consuming right now than usual, and even the victims who don't wind up dead are a hassle to fix and don't look like they have a pleasant time on the way there or subsequently, so allowing her to go about her business is not on the table. If you really want rid of her, you want to talk to me."

"...Look, why don't you just split us, then," he says, throwing up his hands. "And put her somewhere far, far away where you can deal with her and I don't have to."

"Look. Ben. I'm sure having her intermittently possess you is very annoying and you just want it over with without having to endure any further hassle. But I don't think you would want me to just teleport you to Mercury and attempt to pull her out of you there if you thought about it. I don't know what will happen if I do that. For all I know, you will die as soon as I do it because of some kind of dependence between you and then I have to go haul you back which could take me a while, or she'll triple in power and be strong enough to give me a difficult afternoon once you aren't attached to her, or she'll go terrorize her original subworld and then I have a difficult rebellion project on my hands, or something. Some of those outcomes are not great for you."

"She can't get back to her original hell dimension," he says. "And I thought you said your magic could split us. Either you can do the impossible or you can't. How am I supposed to know exactly what impossible things you're claiming you can do when you won't tell me what they are or how you're going to do them? If you don't even know that I can live through it, why are you suggesting it at all, and especially why did you suggest it without mentioning that up front? This is not helping with the trust thing!"

"Dude," says Bella, pinching the bridge of her nose, "I told you, multiple times, I don't know if I can do it till I try it. I can do all kinds of wild things, but neither I nor my friends have encountered the specific scenario of 'hell god possessing human' before. And I'm trying to find out whether you can live through it, so that if the answer is 'no', I can find another solution. You aren't helping with the 'find out' project, so I'm trying to explain why it is important and you should wish to be helpful. That doesn't mean that I'm going to charge blindly forward in the absence of the relevant information."

"How am I supposed to know if I can live through something that's still, as far as I've ever known, completely impossible? And if you're so keen on sharing information how come you're not telling me a damn thing about how you plan to accomplish any of this?"

"Offworld magic," sighs Bella, looking skyward. "There are lots of worlds, you know that already 'cause Glory's from one, but Glory's from one in the same collection as this one we're standing in. I got some magic from some friends who are from other world-collections. What else do you want to know about it?"

"...How it works?" he suggests. "For example?"

"Wishes. I have some wishes on my person, of various sizes, and I can spend them at will."

"And you couldn't, for example, wish to unstick me from Glory and put her on Mercury and leave me the hell alone...?"

"Think of the wishes as magical computer programs," Bella says. "If I wish 'unstick Glory from Ben, put Glory on Mercury', then this will either work or not, but if it works, something I haven't thought of could cause something I don't expect, just like computers don't always behave even though no one expressly programmed in any bugs. That's why I have to think of all the things that might go wrong first. What will Glory be able to do when she's unstuck? How fast will she be able to do it - faster than I can stop her? Are you, in some way you have not chosen to tell me about, attached to her in such a way that you will come to harm in her absence if I don't specifically wish around it? I know some people whose lives are dependent on external souls that are shaped like animals, it would not be the weirdest thing I've heard if your life is in some way dependent on Glory's occupancy and I can probably work around it but I have to know how to be sure."

"I'm telling you," he says, frustrated, "I don't know anything about what could possibly happen if you managed to yank her out of me somehow."

"And I'm telling you, I can potentially use anything you know about her at all in order to find out. I have other sources of information too, I just need to know what to look for."

"What sources? Look how?"

"I have a research guy who's investigating assorted books. I can spy on the past, if I know when and where I want to look. I have a crystal ball, but I have to interpret what it shows me in light of whatever I already know. I can wish up other information-gathering abilities if I know what sorts of things I need to find out."

"Okay," she sighs, since this is not a lie. "In the meantime - I can precipitate shifts between you and her, I did this most recent one. Would you expect anything bad to happen if I pushed you out front more often?"

"...No?" he says doubtfully.

"You don't think it'd make her hungrier for human brains, more pissed off, anything like that?"

"It might make her more pissed off," he says. "Or she might not even notice. I have no idea."

"Okay. I guess I'll take you back where I got you now, then, unless there's anything else you'd like to tell me."

She checks to see if anyone is watching his car.

No one is watching his car.

"Whatever," he mutters.

She is correct.

In this world's original Jarvis.

"Hi, Bella."

"Hi, Bella," says Tony. He is cuddling Soph.

Soph is cuddling back.

"So, I can poke the hellgod into turning into her mortal host with a pentagon, the mortal host doesn't trust me and doesn't know much, I've got Giles looking up Glory and - relevant topics, and I'm going to check on Glory-or-Ben every few minutes so I can intercept if she's about to eat somebody else."

Ben drives home, takes a shower, and goes to work at the hospital.

After an hour, Sherlock appears on Mercury.

"Hi, Sherlock."

"Would you like to hear about the Key?"

"Yes, please."

"The Key is a kind of magical artifact with no fixed physical form that can be used to open a gate between worlds. Glory's home dimension is unusually difficult to access; she wants to use the Key to go home. The monks we saw were trying to keep it from her, and when she discovered them they cast a spell to hide the Key in the safest place they could think of: under the protection of that undead ex-Slayer with mysterious powers who's been making diplomatic overtures to so many demons lately."

"Do we know why they didn't want her to go home?"

"Because once she opens the gate, she is under no obligation to close it, and may instead choose to lead an army of demons out of it and conquer the planet."

"Ah. That would be bad."

"I agree. Not relatedly, Tony wants to know if you'd like someone to talk to about all this."

"That would be spectacular, but I'm skeptical that anyone wants to listen to me unless there is someone I know well enough to pour my heart out to but not well enough that I ever 'mentioned' having a sister." She shakes her head. "Is there a reason to want Glory not to be home that is unrelated to the gate? Like, should I not give her a lift if that seems expedient?"

"Tony wants to listen to you and has explicitly offered to do so. I suppose it's up to you whether or not you know him well enough. It's possible that if Glory goes home she might make life even more unpleasant for the demons who live there, but it's very unlikely that anyone from that dimension could leave it again without the Key."

"So that's an option if I get a nasty surprise about how difficult she is to manage at some point, I guess. I kind of expect that if I talk to anyone who likes Soph and I'm not self-censoring to the point of rendering the exercise useless they will quietly hate me."

"Tony is not going to hate you."

"I don't hate you either," he adds. "But I'm not the right person for you to talk to about Soph. The situation feels very personal for me in exactly the wrong way."

Bella nods.

"But Tony can listen to you, I promise."

"...Okay."

Tony is sitting by himself in his room in the original Jarvis.

"...So apparently you signed up to listen to me process my feelings aloud, but I don't think Jarvis did, and I'm going to wind up saying a lot of things I don't endorse so I'd rather limit the audience."

"Apparently you found her in your room and freaked out and teleported her to Canada?" says Tony.

"Yeah. And I guess she brainphoned Sherlock for help, and - to the extent that there were sides he was not on mine - and I'm talking to you instead of him now because I guess he identifies with her or something? But like - I feel like I've faceplanted into an expectation that I treat my mental opacity like it is the problem here, like, we'd all be a happy Soph-including family if only I'd had the courtesy to be brainwashable? And instead I am the only person I know who has not been brainwashed, and the problem Sherlock chose to address first after concluding that I wasn't crazy was that I wasn't being nice enough. Like - is it just me or is that a complete failure of perspective-taking - what would he do if he woke up one morning and discovered that - I don't know, that his cloning retroactively yielded an extra that everyone remembered but him? Soph was alternately defensive and quiet, I have no actual personal beef with her, but - Sherlock."

"Aww, man. It's not your mental opacity that's the problem!" he says. "Do you want me to explain Sherry? I can, I'm good at that."

"Yeah, explain me some Sherlock."

"If Sherry woke up one morning and there was an extra clone in the family that everybody remembered but him, he'd get right into figuring out what the hell was going on, but he'd treat the extra guy like family unless he found out he was some kind of camouflaged assassin or something. He empathizes way, way too strongly with the whole 'brand new extra person' situation to do anything else."

"...Okay. I don't know how to do that, though, I'm not Sherlock, I can't derive a reasonable picture of her personality from ten minutes of talking to her and her tacky taste in jewelry, she's not even an alt of Lexi. Soph had the idea that I should act like she's some other Bell's sister, which was a good idea. Which I can do because I met Lexi and didn't find her deeply bewildering. If Lexi were stranded here, I'd know how to react to that - I mean, it'd involve a lot of trying to get her home to Aurora, but I don't imagine anyone would complain about how I treated her in the meantime. But - that isn't what happened. Everyone else changed too. I don't know how much splicing her in has affected your memories or the Jarvises' or Sherlock's - let alone my parents, god, Aurora's on record speculating that she has the worst relationship with her parents of any Bell specifically because she wasn't an only child and it made her neurotic. Do my parents now remember raising a neurotic standoffish child who was never confident that she was loved enough? And I mean, Aurora is noticeably different from the rest of us, she has an exactly standard backstory right up to 'move to Forks, find magic and a significant other' but she still acts - off-center. Not in a bad way but in a different way. I don't expect this to add up to much with people I don't interact with socially on a regular basis, but my parents - And Sherlock! Now he remembers meeting and being interested in and teaching and engaging in Slaying with and - all that - a Bell with a sister. The fact that the Bell he remembers now never existed and I do instead doesn't mean it's really me he remembers. Having a sister a year younger than me would've affected me. I don't know who all the brainwashed people remember. I'm not her. For a distressingly large fraction of all practical purposes, he met me earlier today, in Canada, shouting at his friend."

"...Well, first of all, he's off designing a wish right now to get his original memories back without fucking up the new ones," says Tony. "I might do the same thing if he doesn't think it'll mess with my head too badly."

"That helps. He didn't tell me that."

"Yeah, I figured."

"I'm pretty sure I can't do an equivalent. I don't think I can pull a - variant on Shell Bell's merge with my self-who-never-was. Even if I decided I absolutely, without reservation, wanted to, I think I almost certainly resist mental editing."

Tony shrugs.

"And of course it wouldn't make sense for Soph - she can't well remember not existing - so she knows someone I am not and could not be even if I wanted to."

"I think Sherry said something about - alternate pastwatching?" he says. "So you could find all that stuff out."

"Yeah. Now I have homework. And - it's a lot of homework, it's seventeen years of homework, I can watch most of it at greater than the original speed and I can skip over parts where we're just sleeping in our twee little bunk beds and so on, but if I'm at all thorough it's years of homework. And - I asked, I grabbed, responsibility for the whole world. I don't resent having to deal with Glory, or talk to demons, or eventually interface with human governments. I don't resent the obligations that I volunteered for when I helped myself to ludicrous amounts of power. But I resent the - personal imposition. If someone does something and then I have to go kill them or undo it or find their creation a nice quiet subdimension to peacefully live out its days, that's fine, that's part of the job, I signed up for that, I clock in and clock out at highly irregular hours but I can clock out of that. If I even start with Soph I don't get to live with her being my 'sister' some limited number of hours every day, or only when there's a crisis, or only when I feel like it, and I didn't sign up for that and I am not used to it from earliest toddlerhood and that's my life and I want to decide what goes in it without demands like that. Like, at least if Renée and Charlie improbably had a baby right now, I would get used to the baby from a starting point where its primary needs involved its physical safety and we'd work out our more complicated interactions over a longer period of time, from scratch, bit by bit. Soph already has some set of expectations for how having a sister works for her, and what if I hate it, what if I do all my homework and whatever she remembers only works if I'm a year old when I first encounter her and she's little and cute at the time?"

"Then you both have to deal with that," he says. "There's not always a perfect answer. You just... have to do the best you can with what you've got."

"Maybe. It's very tempting to just give up. Not bother. Wish Soph the best of luck, act extremely awkward around Charlie and Renée, get on with my life. Move officially out of Twee Bunkbed Room and be out of her way, Sherlock can pass her coins under the table if he wants, he's the one who makes them. Screw the homework, I have a world to patch and a Mercury palace to design, you know? Except I'm pretty sure if I did that I wouldn't have a boyfriend any more and that is not helping me evaluate the possibility on its own merits or dismerits."

"...Well... I haven't actually talked to Sherry about that, and I'm not saying it wouldn't throw him because it really would, but I'm pretty sure he wouldn't just dump you over it."

"He wouldn't be happy," Bella says. "I guess if he's gone this long without dumping me he probably isn't going to, but - ugh, sometimes I feel like our entire relationship is a string of new reasons to be tense and uncomfortable. This wouldn't help. But I'm not sure if that's even a good reason to consider being all - sisterly, with Soph."

"Could you think about the other reasons and then come back to that one?" he suggests.

"Yeah, I guess." She sits back in her chair. "So there's Soph herself, who near as I can tell is an innocent victim of sorts, who does not deserve to go through the subjective experience of losing her sister, and whose actual - so to speak - sister I have no hope of producing from the depths of Downside Jane or no Jane. She's probably entitled to some attention from me on that basis alone, but I don't know her well enough to know how to do that short of actually doing my seventeen-years-of-homework bit - which even if I decide to do it, I can't do it instantaneously, so there's the question of how to act in the meanwhile. There's Renée and Charlie - I don't even know whether to tell them that their younger daughter is an extremely convincing fiction."

"Yeah, I can't help with the parents," he says wryly.

"I mean, I could leave that up to her, consider her in the metaphorical closet about being what she is, but I don't know how good her judgment is."

"Which is something you could find out by doing your homework," he says. "I mean, or asking somebody who knows her, but I don't know if you want to trust somebody else's judgment about her judgment, and I don't know her that well."

"It's a lot of homework," mutters Bella. "Also I have to figure out how to go about it. Learning to read my own notebook cipher and counterfactual pastwatching will do reasonably well up to the point where we got the brainphone, but after that for a complete picture I'm going to have to read my counterfactual mind, and I'm - well, for one thing I'm not sure how the fact that these events never happened will interact with the fact that even in the false history I was mentally opaque, and for another I'm not sure how I feel about reading somebell else's mind whether she really existed or not. Like, she didn't walk around doing things, but the things she would have done have had effects on you and Sherlock and Soph and Charlie and Renée and so on."

"Sure," says Tony. "I guess you kind of have to figure that out for yourself. But I mean... she is kind of you, isn't she? In more ways than alts usually are? It's almost like that thing with Shell Bell."

"If she were around, we'd be talking mergers. This isn't a merger, it's a - cannibalization."

"Well, she's not around, and you can't - wait. Can you make her be around?"

"I definitely can't help you there."

"I'll need to think about it. I guess it's an option."

"It is!"

"What's Soph even like?" Bella asks, closing her eyes.

"Um... she plays softball," he offers.

That was not the kind of information Bella was looking for. "You and her don't really hang out, huh."

"We do some. But I don't know her that well. I mean, I like her! I just don't have, like, a list of her characteristics on file somewhere."

"I guess that's fair."

He shrugs.

"Do you remember me getting along with her okay, though?"

"Yeah. You guys were fine."

"Like - you've met Aurora and Lexi, right, can you compare?"

"I dunno," he says. "Maybe not as close?"

"Makes sense, I guess, they're twins."

"Yeah."

"I really appreciate you listening to me."

"Anytime."