"Energy?" she echoed, unfamiliar with the word as the Doctor used it, though she'd learned enough Latin -- both openly and secretly -- to at least guess at the word.  "<em>Energia</em>, you mean, force?  But how does that become light?  How long will it last?"<br/><br/>Then she paused, momentarily distracted by what he'd said earlier.  "Your ship is a she, you mean.  Is she fuelled by this same energy?  Does everyone have these wonders, in -- in the future?"  It felt strange and awkward to say it and she felt a little mad herself for accepting the idea so readily, but as perplexing as it was, it also made a perfect, unsettling sense.