A/N: This story sprung to my mind a few days ago and I immediately began writing it (something that is rare with my fics). It ended up stressing me out a great deal because I've never edited a fic this much before (at least not after it had already been written), but here it is now and I love the end result.

I also published this fic on AO3 (username: MidnightHalo27).

This fic takes place during The Silver Mask, so don't read it if you don't wanna be spoiled for The Bronze Key or The Silver Mask's beginning.

This fic has spoilers for something huge that's revealed in The Golden Tower.

This fic has Fullmental Alchemist themes, but no knowledge of Fullmetal Alchemist is needed to read it.

Disclaimer: I don't own the Magisterium book series nor Fullmetal Alchemist.

I hope you like it! Reviews, kudos, etc are awesome! Constructive criticism is very welcome, but flames will be used to roast marshmallows.

Sinner at The Gate

by: GakuenAlicefan27

The idea doesn't come right away.

No, it takes a while. After Tamara and Jasper rescue him from the Panopticon, after Anastasia brings them to Master Joseph, after Call finds out that Aaron's body is intact, it still takes many months before Call thinks to take a different approach on the matter of souls and how to bring one back.

It's not easy. There's his constant arguments with Tamara, and Alex's taunts, and the fact that he doesn't trust Master Joseph as far as he can throw him and doesn't really trust Anastasia either because what the hell kind of mother would want her son back under the wing of the man who destroyed him in the first place.

The fact is: it takes him a long, long time to realize that he should stop going over Constantine's notes and reading the books Constantine read and trying the things Constantine tried because they don't work. He already knows they don't work. Constantine tried them for years and failed, why is Call doing the same things he did.

And with that in mind, Call changes his approach.

~x~

Master Joseph's library covers a wide variety of subjects. Call chooses the ones with the dustiest, most forgotten books and begins his research from there.

It gives him a headache. Most of them talk about topics so advanced he can't even begin to understand what they are about: arithmancy, blood rites, astronomy; not to mention the ones that are downright scary, like demonology and summoning.

Still, he sticks to his decision, and day after day he goes through different subjects, trying to find anything that might help him without necessarily involving chaos magic.

It's discouraging, not to mention boring, but he goes on anyway. The thought that perhaps he should be worrying about other things crosses his mind, but he pushes it aside. There's a big list of things he needs to do: bring Aaron back, get rid of Alex and Master Joseph, figure out what to do with Anastasia, convince the Magisterium he's not evil incarnate…

The key factor is: focus. He needs to solve these things one at a time, or else he'll just end up with a hundred half-done things but nothing fully accomplished.

And so, Aaron it is. Once that is done, he'll move on to the next.

Then, at the end of the second week, he finds something that seems promising:

Alchemy.

~x~

Technically speaking, the magic the Magisterium teaches is pretty alchemy-based. The use of the elements and the principles are all taken from alchemic teachings, but the more complicated things, like the runes and the calculations, aren't really taught anymore.

Which is kind of worrying, because many of the instruments that are still used to this day, Alkahest included, were made taking said runes and calculations into consideration.

Anyway, it's pretty hard stuff. The first few hours nearly convince Call to give up, but it's for Aaron, so he fights the tiredness and does his best to understand what he's reading. After a while, things start making a bit more sense or, at least, start to repeat themselves with such frequency that Call realizes they are fundamental. The most important of them is:

"Humankind cannot gain anything without first giving something in return. To obtain, something of equal value must be lost."*

Call thinks about that a lot, and concludes that that's the problem with Alex. And that was the problem with Constantine. People like them only think about what they can take, take, take, and believe themselves above giving. They believe they deserve things they haven't earned, and ignore the fact that, just because they can, doesn't mean they should.

~x~

Some of the tomes in the library are older than life, and a good number of them were probably illegal back in their time. Call had already suspected it, but he knows it for sure when he reaches the part about human transmutation.

He supposes there are books that cover the topic more lightly - books that do not detail the process and attempts made over history, books that do not describe the after effects suffered by the poor souls who tried, books that do not theorize about where these people went wrong and how they could have done better.

The books he finds in the library are not these books and, for that, Call is glad. Thanks to them, he knows exactly the magnitude of what he's about to do, and what he might lose.

~x~

For many days, Call considers his options, reaching the conclusion that if chaos magic is powerful enough to access souls and other planes, then giving up said magic should be considered an adequate price.

He could be wrong, of course, but that doesn't really change his resolve to go through with it anyway. Even if the price demanded is something else, like a body part, or his whole body, or even his soul, Call will do it.

He doesn't want to die, because he's Call and he's never gonna wanna die; but that doesn't mean that he wouldn't, for Aaron. After all, none of this would have happened if Constantine had accepted death in the first place, so he finds it fitting.

~x~

Eventually, after he's studied as much as he can, he explains his plan to Tamara and Jasper.

They gawk at him as he tells them of the things he's read, and he doesn't blame them. They had no idea he was looking into this stuff, and now he's dropping a bomb on them, considering the logistics involved and the sheer craziness of it all.

But he'll need them. He'll need their help with the drawings in the transmutation circle and the more advanced calculations. He'll need Tamara's eye for detail and Jasper's precision of hand. He'll need them to revise everything in case he makes a mistake in his notes.

He'll need their moral support.

Tamara reads the inscriptions and frowns, looking at Call with narrowed eyes.

"What are you planning to offer in exchange of Aaron's soul?" She asks.

"My chaos magic." He says.

"Oh." She says, surprised. "That could work."

"What did you think I was gonna say?"

Her face reddens, and she looks down before admitting: "Your soul."

And Call doesn't tell her that it's an option because he doesn't know what he's more afraid of: that she'll try and stop him, or that she won't.

~x~

They begin to work in earnest, putting the motions in place. It's difficult, probably the most difficult thing any of them has ever done - The circle needs to be a certain size, the runes are each a different size, the letters are in different alphabets and everything needs to be drawn in smooth, clean lines; not to mention that certain runes cannot be put next to each other, while others won't work without a pair.

It takes them months.

But it gets done.

It gets done.

~x~

Standing just outside the circle, Call thinks of everything he's learned in the past few months. He doesn't know exactly what he will be facing once he begins the process; most of the humans who attempted it had died, and the few who had made it through never spoke of what they had seen.

He looks at Aaron's body, laid in the center of the circle, then looks at Tamara and Jasper standing on the other side of the room, and nods, stepping inside and kneeling down to activate the reaction.

And everything turns white.

~x~

Literally everything is white.

There are no walls, but there's no sky or earth either. There's only white, and a grand door, in front of which an entity sits.

The entity has a white, humanoid body; its faceless head showing a creepy smile that puts the Cheshire Cat's to shame. In between them, Aaron's body is, and in the moment that it takes for Call to look at Aaron and back at the entity again, he suddenly knows its name.

It's Truth, and the place Call is, if it can even be called a place, is The Gate of Truth.

And with those names comes another piece of knowledge: the certainty that his chaos magic is not gonna cut it, for two reasons:

Number one, because Call has never been particularly fond of being a makar, and a sacrifice is not a sacrifice if it's not something you're gonna miss.

And number two, because no one gets to choose what will be taken as payment. Truth decides, and there's no bargaining. It was arrogant of him to think otherwise. Arrogant and foolish, just like all the people who came before him.

But it doesn't matter, he will get Aaron back.

~x~

Call steels himself, and for a moment, Truth changes, rearranges, becomes people Call knows. He sees his father, then Tamara. He sees Master Rufus and Drew. He sees a woman he doesn't really know, but who must have been his mother, and he sees a boy he doesn't remember but who must have been Jericho. Then, it's over and Truth is, once again, a faceless entity, smiling a too-large smile.

Call thinks Truth is amused, if not at the situation, then at him. This little boy who was once a man - and a man who refused to die - now comes through her gates, aiming for a soul and willing to pay the price, whatever that is.

He reckons that Truth has watched him for a very long time, and that it watches Alex and Master Joseph too. They provide entertainment, and so will their demise, when their time comes.

Call wonders if his time is now.

~x~

It isn't.

Call doesn't need to say what he came there for, because Truth knows, of course, but it sure is taking its sweet time saying what it wants in return.

Then, Truth cocks its head to the side and says: "And here I thought you would never change."

Call doesn't answer, but asks: "How much?"

"Does it really matter if I tell you? You already know you don't get a say."

Which is true, but doesn't change the fact that Call would rather know. He isn't worried about it not keeping its end of the bargain, or about it taking more than it should, because Truth, as wicked and beyond a mortal's understanding of morality as it is, doesn't trick you. It takes what it's due, and gives in return, and if an end of the stick seems shorter than the other, that's because the mortal wasn't really prepared for a true exchange, and not Truth's fault.

"But since you asked so nicely." Truth says, and Call prepares himself for the blow. If it's his life, and by all intents and purposes it should be, then so be it.

Because it's Aaron, and he never should have died; the way Call probably shouldn't have lived.

Truth's smile gets impossibly bigger. "Your ignorance."

Call freezes, heart in his throat. This, he hadn't expected. He had come prepared for many things, but this hadn't been a price he'd thought of at all.

Because it shouldn't be possible. It shouldn't be possible for this to be weighed in the scales and be found satisfactory. The remembrance of twenty-something years of horrible memories shouldn't be worth this. They are memories, just memories; painful as they will be, devastating as they will be, they should not be an acceptable price for what Call is asking in return.

But Truth doesn't work with unsuitable prices, and so, for some reason, this must be plausible.

And even if Call wanted to, he wouldn't be able to back out now.

The white of The Gate burns, bright and blinding, and Call remembers. And remembers. And remembers.

He remembers rage and a hollowed-out heart; remembers thoughts and ambitions and monstrosities beyond his wildest dreams. He is unmade and remade in the years of memories. But it's not twenty-something years. It's much, much more.

His chest hurts, and for a moment he wonders if it's the tuberculosis, back to get him like it should've the first time. But it's not. It's just the weight of everything he's done settling back into place, never to be blissfully forgotten again.

And that, he figures, was what made the price worth a soul.

A/N: *This quote is taken directly from Fullmetal Alchemist.

Thank you for reading!

You can find me on tumblr as agarotado27dejunho to discuss anything Magisterium related or just say "Hi!"