The Doctor speaks to Rose:"My entire planet died -- my whole family.... Do you think it never occurred to me to go back and save them?" She goes all shopgirl, protesting that her father isn't a history-changer or a world leader: "'E's not gonna start World War Three or anyfing..." The Doctor steps toward her and tries again: "Rose. There's a man alive in the world who wasn't alive before. An ordinary man. That's the most important thing in creation. The whole world's different because he's alive." And because this is Rose's story, the true paradox is implied: Rose's whole world is different, too. "What," she exclaims, playing dumb. "Would you rather him dead?" The Doctor's not saying that at all, nor is he saying the next thing, as she flips through every possible way she has of denying this. "No, I get it!" she exclaims. "For once, you're not the most important man in my life." Dirty pool. It's never been about how important the Doctor is to Rose -- it's about how important she is to the Doctor. And she knows that. Uglier and uglier. The Doctor is angry: "Let's see how you get on without me, then. Give me the key, the TARDIS key. If I'm so insignificant, give it me back." I think they'd both like nothing better than to back down, but when you're in the middle of somebody's giant issue, it's rough. Without Pete, look what happened to Jackie -- that's an effect. Without Pete to beat his ass, Jimmy Stone talks Rose out of school. And so on. And always in the back of her head thinking of Peter Alan Tyler -- how if he were there, things would be better somehow. He's her excuse. You can't go there without getting in over your head. So if you come up against the edge of the world, if time's hand comes slapping down, whom do you turn to? The people who can do anything: Pete. The Doctor. But it's the Doctor saying no. Rose slaps the key into his hand. "Well, you've got what you wanted," the Doctor says, snottily. "So that's goodbye then." Like a boy, he says this. Cutting with a lie they both know isn't true, and terrified that on some level it is, because that means that all they've been through, and all the love -- all the love in the world! -- that they have for each other was based in something selfish and foul. That when Rose turned her back on Adam, she was being a hypocrite. Playing her own "Long Game."