DOCTOR: First rule of being a detective is to observe. Observe the obvious, and observe the not-so-obvious. Observing the not-so-obvious is not as easy as observing the obvious, but if it were easy everyone would be at it.

DOCTOR: I punched Dracula! He has a very hard face.

MARTHA: I bet. First time you’ve met him?

DOCTOR: No, but the first time it was an android, second time it was Vlad the Impaler and the third time it was a Cyber-Dracula, so I don’t really think they count. Ha! Count.