At some point during this interval, Emily discovers that Bar does the first drink free!

"Nah. Casting spells takes some energy, but maintaining a long-term one doesn't do much of anything. It really is an experience, isn't it?"

"Oh, yeah, I could probably wander in there for days if I didn't need to be out of here in a week."

"...Why a week, in particular?"

"My magic, and also just my baseline existence even if I don't do anything, takes a finite resource. I can't replenish it in here. If I keep it way down, I will have enough leeway to get out, collect more valuable prizes, and recharge. If I wind up in some kind of bar emergency or really, really want to push it, I still need enough that I can go out and - this is going to sound very strange, it's mostly okay and there's an explanation but not a succinct one - if I run too low on magic to be able to take the steps necessary to get more, I need to exit the bar and commit suicide."

"...What good does suicide do you? I'm not doubting you, here, but you've got me curious."

"I'm in a time loop. Which doesn't usually have Milliways in it, so I'm going to milk the place for all it's worth. I didn't find out that my loop resets if I die on purpose, but it does. From where I currently am, the nearest place to get more magic recharging swag is from some monsters I don't have down pat yet - I'm in a city I don't usually visit on a standard run - so I'd have to use some magic to beat them up. If I reset, that doesn't reset my magic, but as long as I have an hour of baseline operation I can steal a recharge object from another puella magi while she's sleeping. If I have four hours I can get to Seattle and find a monster I've fought often enough to reliably kill with no magic, and if I fuck up that option I can still go the theft route."

"Aha. That seems...profoundly disturbing, but in a way that's inarguably not your fault."

"Oh, the fact that I'm in a time loop could easily be construed as my fault."

"Oh?"

"So, puella magi happen when a fluffy alien offers a teenage girl a wish. The wish must be within a certain power limit, but it's still a wish, pretty legit, very appealing, most people don't make good use of them but that's not actually the fluffy aliens' fault. In exchange for your wish you become a magical girl, which has some side effects that people really overreact to - to wit, I am not actually the physical body you see before you, I'm this jewel on my hand, here, operating the body by magic - and some side effects that really ought to be printed on the fucking label. The fluffy aliens are evil, puella magi who run out of magic or get too emotionally fucked up turn into the aforementioned monsters with valuable prizes, and the aliens are running the entire gig because they can get negentropy out of human emotion and this is the most efficient way to do it if you happen to be evil."

"...Okay, I can definitely see where the argument comes from that this is your fault, but I also see that the blame is much more accurately laid at the feet of the fluffy aliens."

"I'm pretty sure they don't handle the detail on the wish execution finely enough to actually have decided to put me in a time loop. I mean, for one thing that would be strategic insanity on their part - they're not looping, only I am, and I now hate them. They're not stupid. Magical girls get bonus magic themed around whatever we wish for. And I watched the biggest fucking witch of all time eat large portions of the world as an appetizer, and I didn't have enough wish to wish her gone - but I figured she had to have been smaller, before - so I wished for another chance to fix it. Only, my magic time travels with me, so there goes my wish, all used up. I have to do it the hard way. It's not that bad, really, between magic and the delight of modern aircraft I have the whole planet to play in before the world ends if I want to take a loop off learning to dictionary-attack the sucker."

"Okay, at that point it sounds less like fault comes into it at all and more like a massive trainwreck."

"Ayep. It's sort of funny, I spent a month trying to come up with a really efficient wish that would come in under my energy budget and still cure cancer or something, and it didn't even occur to me that time travel was on the menu."

"I mean, it sounds like you're deleting everyone who exists at the end of the month and replacing them with someone new with all their memories as of a month ago, this is not the kind of thing you should normally be doing on purpose. Although I'll grant that a world-ending phenomenon is a good enough reason."

"I don't think 'someone new' is the right gloss on it. Like, memory erasure is absolutely happening and I'm not thrilled about that, but that's subtraction, not replacement, I don't have the creeping horrors that my dad is now Dad Replacement Number Eighty-Two or whatever number I'm on - I've kept track but I'd have to look it up. I would probably not have designed a time-travel wish this way, regardless, because I'm not sure that I'll break out of it properly if I do manage to save the world, although maybe I can establish a new checkpoint or something."

"I meant more in terms of the fact that you're a different person now than you were a month ago--that being intended as a general 'you,' not just you in particular, in this particular case I think it bears mentioning. Killing a month's worth of a person is absolutely better than letting all of them die, I don't actually think you're making the wrong choice even if it were an ongoing choice, but it's still killing a month's worth of person."

"I really object to this characterization. Deleting memories is bad all by itself, but it is not necessary to add extra loaded words like 'killing'."

"Sorry."

"Also, under normal circumstances I wouldn't kill any innocent bystanders in order to save others unless the balance were massively skewed the other way, but I will take an extra loop or ten if I manage to kill the big witch but only with more casualties than I feel like accepting, and describing this as 'killing seven billion people a little bit in order to save Vancouver' seems to make it more of a gray area than it really is. What I think of myself as doing is - the memories anybody but me was going to have of that month are gone. And they can only come away from this entire business with one set. My job is to optimize that set so it contains few dead people and little property damage and so I come out the end of it so superlatively competent that I can also then go on to dismantle the evil aliens' humans-as-power-source system."

"Fair enough. I think...with the way my world's magic works, and the things I've had to do with it, I've been attaching less emotion to the word 'kill' than I should be. I will work on that."

"...What, do you have nine lives?"