[Riddick has been quietly stalking his other interactions, and it's not until after he sees Arthas called a scourge-- if not the rest of that conversation-- that he responds.]

Just makin' conversation, really. How're you liking it so far?

[Casual, not at all like a man who's now worried that he's about to get proven a liar for the times he'd said that inmates would be protected from enemies that showed up.]