AN: I wrote this for a friend (a non-fanfiction friend) who likes Fraywood. Hope you like this Buzz-girl!

"As if you were on fire from within.

The moon lives in the lining of your skin."

― Pablo Neruda

Since joining the Shadowhunter world, Clary has come to understand people more than ever before. She understands Simon's heart, Isabelle's closed-off nature, Magnus'… Magnus, and she understands Jace as though he were made of glass. Alec had been just as transparent when she met him.

Which is why it's so surprising when, suddenly, she doesn't understand him at all.

She doesn't understand why he stands abruptly and leaves the room when she enters. Or why he refuses to look her in the eye when she asks him a direct question, though she catches him regarding her subtly when he thinks she isn't looking. In these moments the rise and fall of his chest has stopped, as though he is holding his breath. She doesn't understand why he suddenly says her name as often as possible, as though he cannot say it enough.

And she doesn't understand the frisson of heat that strikes her stomach when he darts from the bathroom to his room with only a towel slung low around his hips. Or why the bitter ache that comes with knowing that she is Jace's sister dulls in his presence. Or why she has the urge the run from the room when his cobalt eyes land on her face. She has hardly ever wanted to run away before, and never so strongly.

When Clary stumbles into him in the darkened hallway of the Institute after visiting Jace, she clutches her sketchbook in front of herself like a shield. But his eyes, striking in the blue hued moonlight, pierce her like a hot spike anyway. So she focuses on his chest instead, hidden beneath a grey t-shirt, when she apologizes.

"Sorry, Alec," she mutters. She steps aside, only to meet his chest again. When she glances up, he's blushing, but he looks amused. When she sidesteps a second time, and he does the same, she realizes they're both blushing.

This is ridiculous, she thinks, and, without thinking, grabs his elbow. She can barely hear the hitch in his breath over the catch in her own. But she stumbles around him and releases his arm.

"Are you going home, now?" Alec asks, with genuine curiousity. It surprises her, as she has only ever heard various degrees of wariness or trepidation in his voice when he addresses her.

"Yeah. My mom is probably going to kill me for being here so late," Clary says, and hefts her bag over her shoulder. She wishes she wasn't so tiny, so her bag wouldn't slide off her shoulder, and she wouldn't have to adjust it and draw Alec's eyes to her shoulders, bare in a tank top…

Her heartbeat thunders, spontaneously blooming inside her chest and beating a tattoo against her ribs. She imagines the midnight flower in her chest, opening its petals like the birth of a star. Normally, the image conjures the memory of her first kiss with Jace. Before they had been cursed with the same blood and the same burning desire. But those memories die under Alec's stare. She shivers, though she feels almost uncomfortably warm.

"Are you cold?" he asks, attentive to the slightest detail.

"No-" Clary begins to say, but something, the something, stops her tongue from forming the words. "A little. Do you have a sweater or something I could borrow?"

His eyes go wide with surprise, but he nods and leads her down the hall, past Jace's room, from which she emerged just a few minutes (really, only minutes?) ago. They are both quiet, and as much as she tries to deny it, Clary feels almost guilty, following Alec to his bedroom and trying not to notice the movement of his muscles beneath his shirt. When he opens the door, revealing a white room with a bookcase, a nightstand, a bed, she firsts her hand so tightly at her side that her nails leave a line of red crescents on her palm.

"Come in," Alec says, and it is not just his words, but his voice, that are an invitation.

Biting her lip, Clary steps inside to accept.

TBC…

AN: I think, because I'm really thankful to my friend for supporting me in my writing in general, that this will be a 2 part prompt. Also, I kind of really love Fraywood.

If you guys want quotes and/or music to go with a prompt, let me know!