"Erica?" He couldn't stop the incredulous reaction, because seriously, Isaac and Erica? Of all the people to end up stuck here with, they were definitely some of the last he would've chosen. And the idea of trading Stiles out for Erica was - an asshole thing to even think of, really, enough so that a flash of shame crossed his features.

He managed to calm down marginally before speaking, but his tone was still animated - maybe even a bit aggressive. "When did she get here?"