"What year are you from, Sam?" He was tired and couldn't recall if Dean had ever mentioned where and when he'd come from. "It's a screwdriver that's sonic, I'm guessing it hasn't been invented where you came from."
"The sound," his voice turned thoughtful, "the evenness of the tone probably has something to do with the glass bending the sound." The Doctor was imagining technology well beyond where Sam came from - perhaps they'd turned the glass wall itself into a transceiver. Stranger things had happened, after all. It would be brilliant to boot.
"Expired? What's that supposed to mean? Almost like some sort of joke, not that anything in this place is the sort of thing to laugh about," and if Sam had asked him, the Doctor would have mentioned that laughter in some form might actually help people cope a bit.
"Something tells me they have more extensive technology that cameras," he'd just be leaving it at that.
"Have any hypothesis as to why we're all here, Sam?"