Shaking Shoulders
Words: 206
This is me getting over a week-long (and still ongoing) writer's block.
The Doctor got lonely. Donna was aware of that. He lived long, and was the last of his kind. His companions would always eventually leave him, as had Rose.
It was up to him to protect the universe, and it didn't matter at what cost. The Doctor would always end up sacrificing something, sometimes someone.
No one would think this when they first met the mad, skinny alien in a suit and trainers, but he had the fate of all humanity (and alien-ity) on his shoulders. Donna didn't think it at first, but once she saw the Timelord mad. . . well. . . she believed it.
To think that the only thing keeping the universe going was the Doctor was absurd. But it was true. And Donna worried about him.
Because sometimes his shoulders, so strong and sure and keeping up the world, would shake. The Doctor wouldn't be able to save everyone. And he would beat himself up over it, and Donna wouldn't know what to do.
So, yes, Donna worried about him. Even though she knew she couldn't help him, she would try. It was so much more important than her unaccepting mother, than Lance's betrayal. Because the Doctor was her best friend.