He holds his breath when he watches her face drain of all its color and then he looks down at the floor, hands loose and useless at his sides as she works it all out in her head. He knows it won't take her long. She's smart, and she knows Allison as well as Scott.
Stiles can hear the difference in her voice when she speaks this time. That she's shifting quickly from anger to resignation, exhaustion...despair. He hates himself for being the reason behind it. For ever believing -- truly believing what he was doing was a good thing. That it would solve things. He's still at war with himself over most of it, but when he'd left he never imagined it would break the people he cared the most about.
In hindsight, he knows it's stupid. He's always been quick to assert who the most important people in his life are, but he's never once assumed he meant that much to any of them with the exception of his dad. Even with Scott -- maybe especially with Scott sometimes -- he's always seen himself as holding people back. Of clinging too hard. Of being too dependent. He's never assumed any of them needed him. Not really.
"I'm sorry," he whispers, ignoring the tear that trickles down his face.