Why Rose Tyler is a Fantastic Companion

First, we have the Doctor, who has come up with yet another brilliant plan that could save the world…but he hesitates. A war-torn timelord who has lost everything and has become a loner, a survivor, has found something to hold on to. He hesitates, because even with the entire world at stake, he just wants to save this one person, this one girl. And more than that, he tells her. He could have saved the world, or he could have saved Rose and everyone would have gone along with his plan, but instead he chooses to tell her why he’s hesitated. Basically, he’s opening himself up to her, telling her how much he cares about her.

And then Rose—beautiful, wonderful, fantastic Rose—tells him to save the world. Unlike the Doctor, she doesn’t hesitate. She just tells him to do it. She is so selfless and heroic. It doesn’t diminish what he’s doing by telling her, either. She recognizes that he’s saying he cares for her and she’s reciprocating by allying herself with his cause, by learning from him, by understanding what it means to be a timelord or a companion, what it means to be the savior. And she knows that no matter what, her life is not worth any more than the billions of lives they could save together. She doesn’t hesitate, she just tells him to do it.

Why River Song's Life Sucks

River has had such a terrible life. She’s kidnapped as a baby, we see her dying (and regenerating!) as a child, she spends the majority of her life in prison (even though she can break out whenever she wants)—but mostly her life is terrible because she hasn’t known her family and when she did, they didn’t know her.

When Rory shows up at the prison, she knows exactly who he is, but she doesn’t recognize him. I don’t think she’d met him yet, but here he was—her dad!—coming to get her…and he hasn’t the foggiest who she really is. All her life River has known about Rory, the Last Centurian, her father. All her life she’s been told that he would go to the end of the universe and stop at nothing to save her. And here he is, right in front of her, on her birthday.

For a split second, she’s excited: her dad is here! He came all this way to be with her on her birthday! But he didn’t; he’s not there to celebrate, he’s not even there for her, he’s there for the Doctor. It’s this crushing reminder that no matter how much she learns about her family or how much they will eventually know about her, she’s not a part of their lives and she lives out of order with those closest to her. Every day of her life she knows a little more, but everyone around her knows less: knows less of her. Slowly she watches everyone fall out of love with her, even her own father, even on her birthday.