Ben is encouraged by that small ghost of a smile, no matter how fleeting it was. There had been nights, awful nights, when he had desperately just tried to get Klaus to laugh, even a little, to relieve the pressure of how awful everything was. To try to keep him going for one more day. So he knows this game, or a variation on it.

"See, I never would've thought to even look for a filter. Is it good to know where it is? I mean - does it help with anything, or is it just interesting?"

He thinks the question might be a safe one to ask; unless this water (and that would be a shitty coincidence) is the source of her anxiety, it's a topic he can ask about that is concrete, related to her own knowledge, and isn't personal. He's just a guy wanting to learn stuff. And the truth is, Ben's interested. It's not just phony.

"It's kind of a long and boring story why, but for years before I showed up here, I couldn't feel stuff. Like physically. And I totally forgot how nice water feels. I know I must sound high or something, but honestly I could just sit here and do this all day."