He considered her reply for a minute, looking thoughtful, then nodded. "It makes sense," Thomas replied, finally. "I'm not sure I'd ever thought about it, particularly, before. But then, I suppose there are all sorts of things like that, that we just don't stop to think of." He gave a faint smile, taking another sip of the water. "It is comforting, too, just knowing that I- we," he amended, quickly, "can keep this place running as well as we do."