“Ooh, do you know a lot of music theory? That could be really helpful for spells. I, um, didn’t get any instruction in it before I came here…”

Vanya’s eyes dim; his whole body sort of droops. 

"I know music theory! Not the whole AP exam's worth but like some."

Vanyel is now DISTRACTED, and has to spend several seconds dragging himself back to the here-and-now. 

"I - sorry - oh. Yeah. You could tell me some of it?" Maybe he can arrange it so that she will talk and he won't have to try to keep up. 

"Sure! Um, I think trading is normal here, do you wanna teach me spells for it -?"

Vanya immediately shrinks and looks SO sheepish. 

"Oh! Right - of course - sorry, I didn't mean..." He trails off into a mumble. Takes a breath. "What sort of spell? I've got one for exploding mals, if you want that." 

"That sounds really good!"

"Sure! Uh, the original's in Russian and I did a translation to English that works but I don't love it yet, it's less mana efficient and the prosody's not quite right - want me to show you how I do translations for songs, it's a bit different than for spoken spells, you can get away with being less literally but you really have to get the syllable emphasis right for the melody..." 

Vanyel is running very low on energy at this point, but this is the most interesting conversation he's had about song-spells in multiple months and he's not going to miss it for anything. He digs out paper and gets to work on finishing his translation, narrating the process to Rebecca (without, of course, actually mentioning any of the Russian words or writing down the letters where she can see.) 

"Yeah I want to know how to translate magic songs!"

Vanya shows her his translation and explains the various choices he made! He's clearly very good at this, and very practiced, though he's also getting exhausted enough that he's a bit sloppy and not exactly clear in his explanations. He keeps getting distracted by noticing a line he doesn't like and then spending the next two minutes mumbling under his breath and scribbling notes while he tries to figure out something better. 

Eventually, after a few more tweaks, he seems satisfied or at least less actively dissatisfied. He offers to demonstrate - not on an actual mal, of course, but he can cast it with next to no mana input and just set a bit of paper torn from his notebook on fire, to show her that it works for real. 

She appreciates this, and copies down the English version.

"You sound super tired," she says. "Did you not get enough sleep last night?"

"I never get enough sleep," Vanya says tonelessly, without making eye contact. "Want me to demo it or not?" 

"Yeah I do but do you want me to lullaby you if you wanna go to bed early tonight?"

......Vanya stares blankly at her, because he has no idea to respond to that, and he tries to think of an answer and fails and after about ten seconds of awkward silence he randomly bursts into tears. 

Oh no did she say something wrong?

Marcy has been alternating between math, perimeter checks, and quick glances to make sure Vanya is still where she left him, but now her head whips up and she shoots Rebecca 0.5 seconds of instinctive death glare before realizing that she might need Rebecca to stick around and explain or apologize or something rather than running away. "Hey, what's the matter?" she asks Vanya softly. "Do you need anything?"

Vanya is sobbing and shaking hard enough that his first attempt to answer comes out utterly incomprehensible. 

He takes a shuddering breath and tries again. “Not - her fault - my fault - sorry sorry sorry -“

"You don't have to apologize; you haven't wronged me." She guesses it's possible he wronged Rebecca somehow while she wasn't paying attention even though that seems pretty unlikely.

"Is it - bad here to offer things like that -"

"What did you offer? I was focusing on the homework," Marcy mutters to Rebecca.

"He seemed tired and I said if he wanted to go to bed early I have a lullaby spell - it always worked on my sister -"

Vanya makes a valiant effort to pull himself together enough that he can speak comprehensibly. 

"S'not - not bad - was really kind of, of you -" 

And then he curls up in a ball and goes back to sobbing even harder than before. It's definitely starting to attract some attention in the library. 

"Do you want a hug?"

Mumblemumblesomething but at least it sounds vaguely affirmative? 

Hopefully that helps and Marcy doesn't end up with a reputation as someone who helps Chicago muggleborns and crying people.

Hug!