The Doctor: Only a madman talks to thin air. And trust me, you don’t want to make me mad.

Oh my god. I’m the tin dog!
Legend says that the Face of Boe has watched the Universe grow old. There’s all sorts of superstitions around him. One story says that just before his death the Face of Boe will impart his great secret. That he will speak those words only to one like himself.
Hello! Oka — [gulp, nauseated expression] New teeth. That’s weird. So where was I? Oh, that’s right — Barcelona!
It’s something unpredictable, but in the end it’s right.
I hope you had the time of your life.
Please, when Torchwood comes to write my complete history, don’t tell people I traveled through time and space with her mother.