>Did you really believe that?
This scene is about so much more than that, though. Just before this gifset starts, the Master is looking past Martha to address the Doctor. “Such a disappointment, this one,” he says. “Days of old, Doctor, you had companions who could absorb the time vortex. This one’s useless!” He’s insulting Martha twice over — once with the literal insults he’s saying, and once by addressing his words to the Doctor rather than Martha herself. He’s completely dismissing her as worthless.
This is important — is critical to understanding her character’s arc, I would say — because it’s exactly the sentiment that Martha has been struggling with all season-long. The whole time she’s traveled with the Doctor, she’s felt as though she doesn’t measure up. The Doctor talks about how great Rose was, he keeps secrets from Martha, and then as John Smith he falls in love with Joan Redfern, rather than her. When she meets Captain Jack Harkness, he too enthuses about how amazing Rose was. And when he does, you can tell: Martha Jones doesn’t feel like she can even hope to equal Rose.
That’s what Martha’s journey is all about: struggling to find her own worth as the successor to someone who accomplished great things (not the least of which was winning the Doctor’s hearts). When the Master dismisses her from his consideration and insults her abilities to the Doctor, he’s externalizing Martha’s biggest fears.
And what does she do then? She laughs. She laughs in the face of her tormentor, of her own personal fears personified, and then proceeds to calmly and with a smile explain how she’s foiled his plans. She’s outsmarted and tricked the Master, one of the cleverest minds in the universe. In the process, she shows just how wrong his opinion of her was — which in a way was also the Doctor’s opinion of her and her own opinion of herself. It’s an incredibly powerful moment, and I think it’s the real climax of her dramatic arc that season.
It’s so much more than just being more “genre-savvy” than the Master.