She understands him now, more than ever before. All that running, she thought it for fun. She could almost laugh at how naïve she had been back then. Because now she knows he had been running because he didn't dare look back, couldn't stand to see all the face's he'd left behind, all the people who had died for him. She understands because now, she runs too.
At first she doesn't notice it. People come to work one day and don't the next. She never bothers to notice the faces of those people, too caught up in her own despair. But she has caused their deaths, for her own selfish needs, so she could get back to him. And now she wonders: Was it worth it?
Slowly she starts to realize what she is causing. Next is Pete, dying because she has failed to check the circuits of the technology she was designing properly. He only looked at it to please her, so she wouldn't sulk so much. If she had fixed it properly everyone would be fine… And now she is constantly plagued by so many 'if only's'…
She knows that Jackie has never forgiven him for her husband's death, although she never actively accuses her out loud. Her father's death has thrown a shadow over her once joyful, complete family. It is her fault Jackie will never grow old with the one she loves, that she has to brave this new world all alone. And it is her fault Tony is forced to grow up without the father figure she had always craved.
The next is an even bigger blow to the family, and again it is her fault. It all gets too much for Jackie, in this new world, her husband long gone. She knows her mother isn't coping with the loss, knows she is slowly dying, but she fails to recognize this and do anything about it. When Jackie commits suicide, she isn't completely surprised, nor completely fazed. But now she cries at night thinking of all the ways she could have stopped it.
Her and her doctor adopt her younger brother but fail to care for him properly. Torchwood is her life and she isn't prepared to give it up for the child. Nor does she desire the role of mother that is thrust upon her. She thinks it is wrong; Tony is her brother, not her son, so she raises him as such. Or more, she fails to raise him as anything. Because now, looking back on it, she knows she was so messed up.
She thinks she has escaped Death's path for good, but she is wrong. They are on a field mission and they have badly miscalculated. Outnumbered and with minimal firearms, there will surely be casualties. A bullet aimed at her is intercepted by her love's soft, human chest. She isn't even been able to retrieve his body as they run from the burning building. And now she will always crave that life they lost.
But he leaves her one final gift: a baby. Tony is almost grown up now, at fourteen he is never around. She vows to care for this baby properly, and not make the same mistake twice. She will carry this piece of her husband with her, as a reminder of him. But her resolve is broken when her daughter comes so many weeks premature, her tiny pink limbs still as she stares into her glazed eyes. Now she wishes that it had gone the other way.
Tony is seventeen and war is raging in America. He is one of the first to enlist. Desperate to escape the life he has been given, he craves the war as his savior. And in a way, it is. She waits at the depo for his ship to return, her arms laden with flowers. By the end of the day those flowers lie trampled on a road side. And now each year, she takes the day off to remember her brother.
With no one left and no one to love, she decides she's had enough of London. She desires the open air, to be free. She travels the world, alone, never stopping in one place for more than a few weeks. She meets some people, ruins a couple of lives, but she didn't stop to see the route of her damage. Now she wishes she had slowed down just a bit.
By now she's realized that Bad Wolf is altering her DNA. She isn't aging, yet she doesn't care. Or more, she doesn't pay attention to it. She just continues through her travels like always because now everyone she could have once known will be gone. And now she wonders if it would have been better off differently.
She is visiting Cardiff at the moment, but she doesn't wish to stay long. It is too close to home for comfort. Home, she thinks. She no longer has anything there to call it a home. No, it is too close to London and she wants to get out. Now she's glad she stayed long enough.
The unmistakable whining fills her ears and she whirls around to make sure it's real, doubting it all the way. But it is. There in front of her, the familiar blue box is materializing. The door opens and before he can step out, she has barreled into him, flinging him backwards.
"Rose?" His confused voice rings out, just like she remembers it. She just buries her head in his warm doctor-smelling jacket and holds him there, never wanting to let go. And now she is so, so glad he ever came back.
They travel together now, just the two of them. They still run, but now it's mostly for fun. They help people, they save lives and they help and save each other, more than ever. Because she knows she will never truly be able to forget all she's done, all she's caused and she knows neither can he. But she can tell him anything, and him her and now, they are able to run together.