Idon’t think anyone really knew what to do with themselves. We’ve all spent the best part of four years training as hard as we could to be inhumanly selfish in a way we could only possibly live with because all of us were going round in fear for our lives—if not in the next five minutes then on graduation day at the latest—and you could tell yourself everyone else was doing the same and there wasn’t any other choice. The Scholomance had encouraged it if anything. Everyone-for-themselves worked well enough to get 25 percent of the students out through the unending horde: I suppose up until now that had been the school’s best option. And yes, it now very clearly meant for us to start collaborating instead, but a large building might not understand that human beings have a bit more difficulty shifting their mindset. I wouldn’t have been surprised if all the enclavers had pulled out instantly. I wouldn’t have been surprised if literally everyone had pulled out instantly. In fact I expected the library to empty out within two minutes of my announcement, theatrics or no.

Then Orion said, “I could come back? Whenever it needed to be cleaned out again?” He didn’t even make it sound appropriately martyr-like; just threw the idea out there as if that were a perfectly reasonable option for us all to consider. I glared at him, but it did have the effect of making a lot of other people shuffle uncomfortably.

“Yeah,” Aadhya said. “Look, Orion, we all know you’re practically invincible, but that’s not the same as totally invincible. If you keep hopping in through the gates, sooner or later some mal will get lucky.”

“They haven’t yet,” he said, perfectly sincere.

“Eleven times, Lake,” I said through my teeth. “This year alone.”

“I would’ve had them!” Orion said.

We were both ready to pursue that line of discussion further, but Liesel headed us off. “Don’t be stupid,” she said loudly. “And give us back some decent light.” That was directed to the room at large, and the library lamps instantly put themselves right again, as if they were as afraid as the rest of us to refuse her marching orders. “We must help. Do you not understand?” She slapped the letters. “The purpose of the school is to protect wizard children. But if we are in no danger, we do not need protection. This obviously creates a thaumaturgic flow towards protecting the other children.”

I felt that obviously was a strong and unjustifiable word in this context—as, I suspect, did three-quarters of the people in the room—but Liesel wasn’t pausing to take questions. “If we do not assist the school to help the younger children, then the flow will create an incentive for the school to trade away our extreme safety to improve theirs. For instance,” she added pointedly, in response to the blank expressions all round, “it may begin to lock us out of the cafeteria. Or turn off the plumbing in our bathrooms. Or if another maw-mouth should enter the school, open the wards to direct it towards our dormitory.”

We’d all got the point by then. I’m not sure it was any better if everyone else was forced to help by the school instead of by me lying to them, but I couldn’t help being grateful that everyone had a good reason to do it. It didn’t feel as wrong as me lying them into it, anyway. It was fair, as much as anything in the hideous bargain of the Scholomance is fair: if you had offered any of us a deal at the beginning of the year, that we could just walk out of the graduation hall at the price of going filthy and hungry for three months, eating nothing but what we could beg or trade from the other kids, we’d have taken it like a shot. You could fatten yourself back up as soon as you were safe at home.

“Okay, so—” Aadhya said after a moment. “This is all because the cleansing machinery worked. So we just need to find a way to keep it working, for good.”

That did sound promising, but Alfie said, “Oh, bugger,” half under his breath, and then said, “You can’t. The cleansing machinery can’t be preserved. You can fix it, but you can’t keep it working. Four years is the absolute most you can get. The agglos will do for it by then.”

“The agglos?” Aadhya said. We all think of agglos as party favors rather than maleficaria. Technically, they do need mana and they can’t build it themselves, but they never hurt anyone. They just creep around very slowly and collect any stray bits of mana-infused creations that have been left out and then tack them onto their outer carapaces, like oversized caddisflies. We’d all be delighted to meet a fully grown one that’s been accumulating scraps of artifice and alchemical products for a decade or so. Which is why you never do meet agglos in the classroom levels, except the tiny larval ones. But there are colonies of grown ones in the graduation hall, like the group I’d seen. They hide until graduation is over, and after all the other mals are well fed and snoring, they creep out and collect up all the tidy bits that got dropped by the students who didn’t make it out.

Alfie ran a hand over his face. “They get through the outer shell and just gnaw on the machinery until it breaks.”

“That doesn’t make any sense,” Aadhya said. She wasn’t by any means the only artificer looking baffled. “Why don’t you throw a five-minute warding on it? They’re just agglos!”

“That’s why you can’t ward them out,” Alfie said. “Mortal flame is—well, it’s arguably an entity, and one that consumes mana that it doesn’t make itself. If you want to conjure a mortal flame and send it out, you can’t ward the artifice you’re doing it with against mana-consuming creatures. You have to ward it against malice. But the agglos aren’t malicious. They never take mana against resistance. They just nibble on this thing we’ve left sitting out near them, and sooner or later they make a hole in it, and then they squirm inside and take bits of it until the whole thing comes apart. London enclave’s got a laboratory with an agglo farm that’s been looking for ways to keep them out for the last century. If we could, it would be worth doing anything, spending any amount of mana, to get another team in to do a real repair. But we can’t find anything that works for longer than bloody wrapping the thing in tinfoil—the agglos like that stuff so much they’ll eat all of it before they bother going into the artifice. And that would get you four years.”

We stood around dumbly for some time after he finished. The cleansing was so stuck in all our heads as the obvious thing to fix that even after Alfie’s explanation, at least half a dozen people opened their mouths to suggest some other way to do it, only none of them managed more than “What if…” before they realized that whatever their clever notion was, the brightest minds of London had already thought of and tried it at some point in the last hundred years.

“What if we just fix it every year from now?” one of Aadhya’s acquaintances from Atlanta said finally, the first one to make it past the sticking point. “A crew could go down right after New Year’s, when the hall is freshly cleaned, and,” picking up enthusiasm, “we could make it the same deal as last year. Anyone who signs on for the fix gets a spot, enclave of their choice. Right? People would go for it.”