Martha: When you say "last time", was that you and Rose?
The Doctor: [he pauses, somewhat taken aback by the question] Um... Yeah! Yeah, it was, yeah.
Martha: [looking put off] You're taking me to the same planets that you took her?
The Doctor: [surprised, oblivious] What's wrong with that?
Martha: [disappointed, upset] Nothing! [starts to stalk away] 'Cept have you heard of the word "rebound"?