"...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!"