[Caius pauses in heading back up to give Kor a weird look, like, where did that even come from? What does a mop have to do with this? ... And then understanding dawns. His expression doesn't change much outside of a brief "oh" moment though.]

Wrong kinda spot. Do I look like I came down here to clean? [Don't answer that. Caius shakes his head.] Spots are black monsters that have a weird habit of making nests out of people, or they just grab you and absorb you. A mop won't clean any stains like them up.

[Heh. He carried on the mop-cleaning talk. He's feeling pretty good about that. Nice one.]