A/N: I'm so sorry for not updating in ages! To be honest, I haven't had any inspiration, and this chapter is a pretty far stretch. I have the rest of the story pretty much planned out though, so it should be pretty easy from here.
The fourth time Martha is jealous of Rose Tyler, it's not even really the Doctor that's making her be. But he looks like the Doctor and talks like the Doctor, and maybe he's temporarily a human schoolteacher who calls himself John Smith, but Martha knows that the Doctor is still in there somewhere. And whether he's the Doctor or John Smith, being around him is really bloody painful right now.
Realistically, it makes more sense for Martha to be jealous of Joan. The Doctor has fallen in love with her, after all. But as always, Martha's jealously comes back to Rose. Because even as a human, with no memories of his Time Lord past save fleeting dreams in the dead of night, the Doctor's love for Rose comes bleeding through. Martha sees the pictures of her in John's journal, and she realizes that, no matter how much she may want him to, the Doctor - human or Time Lord - will never see her like that.
Martha's been doing a lot of thinking during the past few months she's spent with the human Doctor. And she's realized she's put herself in an impossible situation. Because she loves the Doctor - she accepts it now, she's head over heels for him. But she also knows that her feelings will never be returned. No matter how hard she tries, she will never be more than a friend.
But what can she do? Martha would go to the end of the universe for the Doctor, without once ever questioning it. She knows it's wrong. She knows she will only get hurt in the end. But every time he calls, she will come running. She knows she'll do anything for him, without a doubt. She's too in love, both with the Doctor and the fantastic life he leads, to stop now