He has no idea that she's approaching him with the idea that he might startle and run off, like a deer in the forest - and that's probably most of the reason he doesn't. Though he doesn't put his arm around her at the moment, his attention has shifted to rest entirely on her, in a way that feels all too familiar for him.

"In that case, we'll just look around to be nosy," Mulder replies, keeping his voice light. So far, he hasn't seen much to contradict Scully. The hints that she might not be as exhausted with him as he'd thought are like catnip, though; if he can find more information on anything here, he'll take it. "Have any working theories for what caused this? Maybe we can do a little more research while we're here."