Considering the fact that Susan's sensibilities and dress clearly reflected an era before air travel was relatively common, she seemed strangely nonplussed about the idea of traveling outside of a world. True, this was partly due to the fact that they were currently outside any particular world, and partly due to the fact that Martha hadn't specified that she'd done so without magic. In any case, extra-terrestrial adventures didn't occur to Susan as a viable topic.

The way she'd said 'other species' was a bit odd, but the idea wasn't odd. Susan was from a place where the term People (and, indeed, human, usually) encompassed a wide array of creatures that most other worlds would have dubbed anything from Pests to Building Materials. Given that she was bound to be truthful, that area of conversation was, perhaps, best left untouched.

"A Time Lord?" Susan asked and couldn't keep a note of mild skepticism out of her voice. "And he's earned that title in only nine hundred years, has he? Bit of a social climber, eh?"

It was a terribly rude question and Susan looked apologetic once she'd said it. She couldn't help herself. Unfortunately, there was no going back and claiming she'd meant to say something else, so she winced and soldiered on.

"Ah, sorry," Susan added, a touch awkwardly. "What in the world is a Time Lord?"