Jace allows Clary’s hand to rest over the rune on his neck for a few seconds longer than he knows he should. It’s a risk, allowing her to be this close, to get this good of a look at anything that might jar her memories and put her at the risk of the angel’s wrath.
But Maryse told him of her last conversation with Clary. She told him what Clary asked, about whether or not Angels are capable of forgiveness, and he has to hope against every single rational instinct within him that this, that Clary being able to see him despite his glamour, to pull his name from her memory and recognize the runes on his skin, is that forgiveness coming to light.
He has to hope, because if it isn’t then he’ll never be able to forgive himself for putting her in danger over his own selfish desire to see her. After all, Simon is able to stay away. He knows better. Even Luke, her own father, never came to a single exhibit, never ‘accidentally’ ran into her at a coffee shop or outside of her apartment. Jace is the only one who isn’t strong enough to stay away.
...but maybe he’s the only one who can bring her back to them.
Her fingernails graze gently over the marks and he allows it because he wants it… he needs this so badly. And then he steps away. He has to - this isn’t safe for either of them.
“I have to go,” he says. “Nice show, Clary. I’ll see you around.”
“Wait! Where do I know you from--” she calls after him, but he’s gone before she can follow.
He doesn’t stop until he’s several blocks away, leaning against the side of a cold brick building, breathing heavily. But it isn’t because he’s tired or out of breath - it’s because he’s terrified of what he just awakened.
Jace pulls out his phone and dials a number. It rings once, then twice, before someone picks up on the other end.
“Simon?” Jace asks, waiting for a response before continuing. “Yeah, I did. And before you get all ‘superior self-restraint’ on me… she saw me. She saw me , Simon.” Jace smiles to himself despite the severity of the situation. He can’t help it. Clary noticed him, but more than that…
“And she remembered my name.”