"I might not look it, but trust me, I am." The one day he'd spent outside between getting back to the States and coming in here had proved that his reflexes hadn't dulled. "I wouldn't suggest you try and surprise me."

He means it, too. Considering how jumpy he is, and the flashbacks he's been having, he knows he'd likely hurt her before he even realize who it was, and the thought frightens him. Another reason not to let anyone get too close.