Probably the cover was misaligned on her copy. She flips through it in case there are any surprises. Whimsically scribbles ", and commitment to print quality" at the end of OUR VALUES.

A quiet thump to her right signals somebody plunking their bag on their desk as they scoot their seat in. 

"Anything interesting in there this year?"

"The hat ban has been clarified to include all non-religious headgear other than small functional accessories including barrettes but not including elastic or fabric-covered headbands. Riveting."

"Ah, the dress code. Maybe this year is the year I get somewhere with the administration on that. Or get expelled for too many dress code violations in protest."

"I think as worded this might technically forbid ponytails held together with anything other than a rubber band but somehow I don't expect it to be enforced on me! I'm not sure you can get all the way to expelled for dress code violations without showing up to school actually naked and that might get you put on a sex offender list too, though."

"I am not planning to show up to school in anything that would be actually unreasonable to wear, that would be entirely contrary to the point. Unless I can find something totally unreasonable to wear that manages to not be a dress code violation, to serve as contrast showing how ridiculous the whole system is, but probably not even then, I don't trust them not to take it the wrong way and just add more rules and call it good. I'm definitely not going to get myself arrested over the school dress code. If I get myself arrested as part of a peaceful protest it'll be protesting something way more important."

"I think it would technically not be a dress code violation to show up in..." Bella peers at the dress code. "Okay, 'distracting' covers a lot, that's unfortunate, they could say anything was distracting."

She makes a face. "Guess it's back to Plan A: Short Shorts until they get tired of sending me home. Good thing we live in Arizona, I don't think that tactic would work somewhere they have more in the way of seasons."

"It really wouldn't. I've seen a couple people wear short shorts over leggings and not get coded, though, it's not really consistent."

"I wore bandanas for weeks before somebody called me on it last year..."

"It's almost like they can tell you're not in a gang!"

"Gee! Almost like!"

She glances at the cover of Bella's handbook and makes a face. "Yikes."

"Yeah, mine got kinda -" She flips back to the cover to run her nails over it illustratively.

"Jeeze, don't they have rules against that or something? I wonder how it didn't get caught."

"It's not illegible and it's just the cover anyway. It's not a big deal."

"Yeah, but you know how big of a stickler the school is about these things. Remember last year when they insisted on reprinting all the yearbooks because there was a typo in one of the club names?"

"- I do not."

"People were bitching because they had already started passing around the misprinted ones to sign and everything."

Bella flips back to OUR VALUES.

The values statement printed in the book now ends with "and commitment to print quality." Printed in the same typeface as the rest of the statement. 

"Whatthefuckingfuck," breathes Bella.

"Huh?" 

Edie flips to the same page, not seeing anything weird. "Is yours as badly done inside as out?"

"No, it - I -"

She fumbles her pencil, catches it, strikes through the remark about print quality, looks back over at Edie.

Edie is frowning at the dress code page. "This is ridiculous, people dress like this outside of school all the time and it doesn't impair anyone's function," she bitches. 

"Hey Edie can you summarize our conversation so far for me real quick."

"I bitch about the dress code and you have practical opinions about defying it?"

"Do you remember remarking on the cover of my handbook."

"No? I guess it looked kinda janky, but like, public school, what do you expect."

"- okay. Cool. Guess I had, like, a - weird - dream? Maybe I didn't sleep super well last night and I'm dozing off."

"Ooh, what about."

"I scribbled in the handbook 'and commitment to print quality' under 'our values', because of how my cover looks, and then you acted like the cover looking like that was very much not public school what do you expect but in fact very startling coming from a school which, you said, last year insisted on reprinting the yearbook over a typo." Bella's writing this down for her own reference as she says it.

"Huh. Well, I certainly don't recall the school reprinting the yearbook last year over a typo."

"Yeah, I must be tired or something." She actually feels kind of wired but maybe that's not incompatible. She flips the rest of the handbook, and her schedule, till homeroom is over.

Corrects a typo in the handbook.

If she flips back to the page her markings and the typo are both gone. 

- okay, well, homeroom is over now so she can't check if she has revised Edie's memories. Twice. Fuck.

She checks, several times per class, if the handbook is still in her bag; but she doesn't write in it again before she can catch Edie at lunch.

Edie waves her over when she sees her with her tray. 

"How were your morning classes?"

"Completely unremarkable. Can I see your copy of the student handbook please."

"Sure?" 

She digs it out of her backpack and hands it over. 

Typo? The principal's name spelled with a extraneous double letter on page 6.

Any changes Bella made to her own handbook are present in Edie's. 

"Oh boy this is weird."

Are there any other typos. She is relatively unconflicted about fixing those. Only relatively, but.

"What's weird?" she asks, peering over Bella's shoulder. 

"Remember that weird dream I told you about in homeroom?"

"Yeah?"

"I'm increasingly uncertain that it's a dream but it - may be retroactively editing people's memories - which makes it hard to prove, among other things."

"I realize that your claim makes it more difficult for you to present evidence to me but can I have an expansion on what evidence you've experienced...?

"There's the part about print quality that I told you about, and then I fixed a typo - there was an extra letter in the principal's name on one page, it seemed like a relatively noninvasive change to fix it - and my handbook now has that typeset like it was never mistaken in the first place, and so does yours."

"I remember what you said about the print quality conversation, but if that already seemed like a dream...with anyone else, I would attribute the typo thing to unreliable memory, but you being you, that doesn't seem likely. Hmm. I wonder if there's anything you could change that would only affect my memory, I can consent to that."

"It didn't seem very much like a dream but it seemed more likely than me having a magical student handbook. - I guess it might be me and not the handbook. I can't think of anything that would only affect you, since... you did not write the handbook, and presumably whoever did remembers doing that. But I could - scratch out some of the more pointed details about student-led protest? As a small-scope change that would mostly localize to you."

"If you make a change and only interact with me before changing it back then probably it would just be like you hadn't changed it from everyone else's point of view...? I should try editing mine and yours and you should try editing mine, for science. Controlled variables etcetera."

"I don't know the metaphysics of this! Something that was definitely added since last year probably won't affect whether, I don't know, one of the teachers had a baby or not, but anything from longer ago will almost certainly affect somebody's baby at least to the level of which sperm. Agreed about editing each other's."

"You have a point..." Edie flips through the handbook looking for obviously-recent things. "We could try the print quality thing again, since any damage that caused is likely already done? Maybe I should poll people about babies since I'm known to do weird things involving talking to a lot of people--no, changes on the level of which sperm wouldn't necessarily be evident in a small child even if we knew what to look for, which we don't." 

"I'm not a hundred percent that I remember my exact wording but I'm pretty sure it was at least very close to what I wrote down separately, 'and commitment to print quality' at the end of Our Values. Do you want to try it in mine or vice-versa first?"

"You already have mine, you go ahead."

Bella preregisters her experiment, and then writes "and commitment to print quality" in Edie's handbook with more trepidation than anyone has ever written those words before.

"Well, I don't remember any yearbook reprints," she says after a moment. 

"Okay." She preregisters the other experiment and hands over her misprinted handbook.

She adds the print quality value, closes the book, and frowns. 

"I remember both the yearbook reprint and the yearbook not reprint. --Uh. I am not sure changing only recent stuff is going to avoid having the effects we want to avoid."

"I don't remember the yearbook reprint, so I guess that means I and the handbook are special. - why do you think so."

"Because it isn't just the school that changed, I remember learning about a Supreme Court case where somebody got killed in an accident and his family blamed a typo in the instruction manual and brought charges against the guys who printed it."

"Jesus! Did we just kill a guy? And unkill him and then return to kill again? - has this affected your memories of homeroom at all."

"Yeah, I remember being perplexed by the cover of your handbook. I'm gonna google the court case while the timeline is still this way and then we can put it back and I can google him again."

"Yeah do that good idea." Are her experimental preregistrations unchanged.

Her experimental predictions now predict changes from a baseline of the new timeline. 

"- shit, it can change my notes."

"That is both not ideal and not surprising. If it couldn't change your notes that would have implications."

"Yeah but it means I have to rely on my own personal brain - or yours and mine together, if you do the changes, which I guess implies you should -"

"I promise I won't go on a mad social justice rampage or otherwise make any changes without your approval. It would be nice if we could do small-scale controlled trials with this that only affected consenting participants but even if everyone in the school was willing to consent we don't really have a way of convincing them to tell us so."

"And it's not just the school, it is sometimes the Supreme Court."

"There are probably changes that could be made to the school that wouldn't need a Supreme Court ruling to justify, like, we ask a teacher something that's in the handbook that could've gone either way and we make it be the other way."

"I guess.

"...I'd be tempted to go public with it to get buy-in for experiments, but -

"- there's basically no way that ends well -"

"Yeah. I mean, if of non-you only the person who writes in it remembers what happened, it seems really hard to, like, scale people believing us. The most likely way would be to convince someone in a position of authority, and...yeah. Plus like. All the other reasons it doesn't end well."

"It's sort of plausible I should take out a safe deposit box and lock it in there and meanwhile spend a lot of time thinking about what to do, but it seems plausible it'll only work this year, or something -"

"It's entirely possible. If only there were a handbook for dealing with this handbook--I wonder if we could extend the period of time it works in, if that's the case, by rewriting how long a school year lasts--or just editing the date--I want to try editing the year on the handbook but I feel like that has, uh, failure modes."

"Yeah. It hasn't determined anything to be a misprint or a prank by the typesetter, yet. If I put the principal's name typo back maybe her name will in fact become Katheriine."

"I'm...tempted to suggest changing something that would have consequences going really far back, and see if me or anyone else in the school disappears and is replaced by other people conceived under other conditions due to butterfly effect, but that's really dangerous and probably not warranted yet." 

"I don't know if it's losslessly reversible! I should try making the principal called Katheriine - or maybe just spell her name differently in a still conventional way, with a C or something - before I do anything I actually care about that I might want to put back."

"Yeah. --I'm going to put the print quality thing back, I googled the guy, and I don't want to let this timeline run too long before switching back."

"Yeah. Last time I just scratched it out."

Edie strikes it through in a single bold line. 

"I can't remember the other timeline anymore," she reports. "I can remember, like, facts I thought about in it, but the general history is no longer available to me." She immediately starts googling the guy from the other timeline's Supreme Court case. 

"I really wish it would let us keep notes."

"Yeah, that's annoying...okay, found him. Looks like he died in the same accident but nobody blamed it on anything out of the ordinary."

"Okay. So we didn't kill a dude, we're just rejiggering the lawsuit related decisions. - Where's Emily?"

"Talking to the art teacher about the syllabus."

"- was she definitely going to be doing that this morning, or did something about our commitment to print quality throw her off -"

"It wasn't, like, planned in advance, but it is highly unlikely to be print-quality-related, she wanted to customize one of the projects that was supposed to come up later in the term and the project was, like, sculpture-related, nothing to do with print."

"Okay. God this is making me so paranoid."

"You know what? That's fair." 

Emily drops into the seat beside Edie. "Hi guys, what's fair?" 

"Bella has a reality-bending notebook and only by the metaphorical grace of a hypothetical god did not accidentally kill a dude with it. So she's feeling paranoid." 

"Wait, what?"

"--Not a notebook, her copy of the student handbook," Edie corrects herself. 

"--For real? Like actual real magic?"

"Yeah. But it kind of retroactively changes everything including notes and memories except my memories apparently and if Edie is the one changing the book hers, so it's a little fraught to demonstrate, I can't exactly go 'do you remember those periods of time today where the school was bizarrely committed to print quality'."

"You are correct that I do not remember such a thing. Print quality?"

"I discovered this situation when, in response to the misprint on the cover of my student handbook, I added 'and commitment to print quality' to the our values section."

She peers at the cover of the handbook, then snorts. "Fair enough." 

"Yeah. And then Edie reacted to it and told me an anecdote about having to reprint all the yearbooks last year over a typo. Because of our commitment to print quality. And then I scratched it out and reckoned I'd been dreaming, but..."

"But. Well. You know, I've read crappy fantasy with worse magic than this in it, but I'd still rather have landed in not crappy fantasy with better magic than this in it. Have you tried to use the book to make everyone immortal yet? That would be, like, the opposite of accidentally killing somebody, if I woke up tomorrow and learned that everybody used to be not immortal I would super forgive you for changing my memories."

"Immortality isn't a school policy and we have been being careful, Emily, changes that big in the first hour is not what careful looks like."

"Yeah, and also I don't know what a high school student handbook in a world where everyone is immortal even looks like. There would be a lot of implied worldbuilding."

"I mean my first try would be to just write 'everyone is immortal' in it and see if that did anything."

"That might work but it might just. I don't know, change the school motto? And also, like, death is bad but there exist some problems people are solving with death and I'd want to try spending a while working on those before I thoughtlessly, I don't know, resurrect someone's abusive parents or whatever."

"I don't think the solution to abusive parents is to kill everybody but since this thing is retroactive I guess it doesn't really matter how long it takes us to come up with an actually good solution."

"Unless the handbook stops working at the end of the school year." 

"--Okay, yes, unless that, but we should probably have something workable figured out by then!"

"Yeah. Cautious but not a multi-year time horizon. I'd just like to make few total changes in case I am obliterating timelines or something like that? Which means getting immortality and something about abusive parents and everything else in one swoop and then making smaller revisions from there as necessary."

"Right, makes sense. And probably coming up with backup plans in advance, like, 'this is what we plan to implement, here are X ways we've thought of that it might go wrong and the Y first things we'd try to do to fix them." 

"I really wish there was some way to experiment to find out exactly how much harm this thing was capable of without doing that harm--like, that one guy was dead regardless, it might be that the book can't change what people currently exist, which seems important to know."

"It would be good to know but I don't want to, like, add teen pregnancy policies and see who has a baby now."

"Yeah absolutely not! That would not be in my first five experiment ideas honestly." 

"What would be?"

"Find someone who recently died of a disease we don't have a vaccine for, add a vaccine for that disease to the required vaccine list, see if they're still dead or not. Find someone whose parents getting together was dependent on some factor we could definitely change, change that factor, see if they still exist. Eliminate the Holocaust and see if our family tree suddenly expands massively. Eliminate malaria and see whether this results in increases in charitable spending elsewhere since the Against Malaria Foundation is no longer taking up charity dollars. Check the efficacy of possible anti-bullying policies."

"The vaccines idea is a good one. I need to read this thing cover to cover this afternoon."

"Yeah. Good thing the non-magic copies have the same contents so we can all do that..." she drums her fingers. "Since the print quality timeline already sort of exists, what do you think of the idea of having people switch between this timeline and that one to prove to them that we're not joking, more brains could be an asset as long as they're sensible ones, and most people are not Emily, to believe without proof on account of crazy twin trust..."

"Nervewracking but possibly a good idea."

"My first thought is our parents--Emily's and mine, I mean, no offense to your mom but I don't have the impression that she's all that natively interested in large-scale world improvement projects, whereas our mom would definitely go on sabbatical immediately to start brainstorming how to change the world via high school handbook. I admit I know less about your dad and could easily be wrong about Renee."

"I think she'd like to know on general principle and wouldn't be actively a hindrance - and she might know more than we do about how school handbooks are generated - but I agree that she will not immediately go on sabbatical to brainstorm. I can come over to your house today maybe?"

"Sure, sounds good. Directly after school or after talking to your mom?"

"I'm thinking get on your bus and call her."

"Sounds good." Edie's parents would definitely want to have that talk in person but Renee Swan is a completely different person. "I'm going to start a list of important problems, possible interventions, and possible unintended consequences of those interventions."

"Same here. Emily, you should too, we don't want to miss an idea because we were all too full of each other's..."

"Yeah. Should we put some kind of moratorium on looking at each other's ideas for, like, a couple days or up to a week? For eye freshness purposes." 

"I think probably at least over the weekend."

"Yeah, I'd be in more of a hurry if it didn't change history but as it does the only real deadline is the end of the year."

"If it didn't change history we wouldn't have to be half as careful."

"I guess? I don't know, a non-history-changing version of this could present problems of its own."

"I mean I was assuming that not changing history would include not changing everyone's memories but that's not necessarily a safe assumption, come to think of it."

"Yeah. And if it doesn't change their memories, how does it change their behavior?"