The fact that she's so quiet suggests to Derek that he's touched a nerve, so he leaves it alone. Instead of trying to engage her again, Derek just starts to wet down the front of his jumpsuit with water before making his way toward the air dryer. He'll be late to the debriefing, probably, but if he's going to get arrested for treason, at least it'll be because he was tardy and not because he's covered in coffee.

He doesn't see her turn toward him or swing right back around because he's paying more attention to what he's doing, but when she speaks, it surprises a bark of laughter out of him and Derek looks over at her, lifting an eyebrow.

"'Chisel [me] out of marble?'" he repeats, grinning with amusement. "I don't think so, but I mean...I could be wrong. I didn't take the whole thing off, you know, it's all right. You don't have to turn your back or anything..." he says, still sounding amused — because he is — but looking back at the jumpsuit he's drying so that the focus isn't all on her, which he assumes is half the reason she's been quiet since they started walking.