"I'll be sure to," the Doctor said, grinning at the man again. "What part of Tokyo is it in? And, ah, approximately when? It won't do much good to try to find it if I'm there in the wrong decade." Or century. Or millennium, but he felt reasonably sure his estimates wouldn't be off by that much.

And hoping for the best, well... The Doctor liked hoping for the best. He liked hoping that humans were capable of living up to their best. He might have commented to that effect, but Mr H had dropped Donna's name.

"You know Donna?" he asked in return, only to realize his question didn't exactly answer Mr H's question. Indicate its answer, sure, but not actually answer it. "I—Yes. She travelled with me. Before. —Before here."