His first thought when he hears the knock is that it's Scott or Lydia. He's talked to other people here, but as far as he knows, they're the only two he has any real connection with at all, no matter how frayed that connection is. He's been in full on avoidance mode since he got here. He rationalizes to himself that it's better for everyone that way -- because once he finds a way to get them out of this place, he's not going back to Beacon Hills. He has plans. He has work to finish.
Then he remembers that Scott and Lydia have both been avoiding him as much as he's been avoiding them and he pauses, setting his book down on his bed, leaving it open to the page he was on. He'd been surprised when he'd given up and finally accepted the key to his assigned room to find most of his things in the closet. His books, some of his weapons, clothes, and various supernatural related supplies. And most fortunately of all: his Xanax and cigarettes.
He pushes himself off the bed, picking up his Desert Eagle and tucking it into the waistband of his jeans before making his way to the door, unlocking and opening it cautiously. There's a woman standing there who reminds him instantly of Lydia, and he's struck with familiarity, like he knows her, even if he doesn't even know her name.