After the feels of the heart-breaking episode last night, this was born. Please enjoy and review.
Disclaimer: I don't own anything from Doctor Who.
It's always hard for the Doctor in the time after he loses a companion. He's the last of the time lords, so he should be used to it, but in the thousand and some odd years that he's lived, he can never get used to it. The silence is overbearing. When she realizes that he is sad and lonely, the TARDIS makes more noise than usual, but somehow that just makes the silence echo even more.
They always leave, and they always break his hearts.
There are times when the Doctor will be fixing something underneath the console, and he'll think he hears Rose Tyler's voice while she talks on the phone with her mum, Jackie. Sometimes, he even hears Mickey doing something to make Rose laugh while the Doctor works. Her light laughter fills his ears when he doesn't want to think of his human, all pink and yellow.
Out of the corner of his eye, he'll think he sees Martha Jones doing something clever to try and impress him. Maybe it's pick up on something he missed, or simply preparing to fight some new monster.
He'll make a comment and already know what smart remark Donna Noble will say, only to have the silence drown whatever thing she might say. Her complaints are only in his mind. She can't even remember him, and the Doctor has never felt more guilty.
Whenever the Doctor is visiting a new planet for the first time, he often hears the deep voice of Captain Jack Harkness say, "Hello," in that obnoxious way that always got them into trouble. He can hardly stop himself from saying, "Stop it." But now Jack is busy with Torchwood and doing his own traveling; he doesn't have time for the Doctor.
There are even times when he thinks he hears a swish of fabric and half expects to see Reinette, more commonly known as Madame de Pompadour, to come towards him and start snogging him. Or sometimes he will think of Joan, and almost be able to see her on the TARDIS, even though she refused to travel with him.
He wonders if he'll go mad from the silence and the ghosts that plague the TARDIS. They're everywhere, and he hates himself for it. The Doctor hates endings, but he can't seem to avoid them. He keeps from saying goodbye as often as he can.
But sometimes he can't help but have to say goodbye.
He almost considers himself lucky when he does get to say goodbye. There are times when the Doctor doesn't get the opportunity to do anything to save his friends.
The Doctor couldn't stop Rose from falling through the Void, and he couldn't save her from Pete's World. The best he could do was give her his clone and the happily ever after the Doctor himself could never have and didn't deserve anyway.
He had no control of Martha's decision to leave him. She was much happier with her family, and now she had Mickey. Neither needed him for happiness, and he always could see them again if he needed to, but it was best for him to leave them alone.
Donna made him feel the most guilty. She was his best mate, and she couldn't even remember the Doctor or she would die. Her mind couldn't handle the time lord consciousness. There never could be a proper goodbye.
Jack didn't need the Doctor. He never did. He had his own friends and life at Torchwood. But Jack is immortal; he's bound to run into the Doctor at some point.
However, the worst goodbye, or lack thereof perhaps, took place in a cemetery in New York City. They thought they were finally safe, but were far from it. A weeping angel sent Rory Williams back into the past, and the Doctor never saw it coming, and never got to say goodbye.
Amelia Pond was one of his best mates, an old friend, and he never wanted to see her go. But at least it was of her own choice. She chose Rory, as she always should have, always would have. How else could the ending have gone? They were able to live to death together, a life that the Doctor could never have with anybody. He would be lying if he didn't say he was jealous.
And then there is River. The first time that he met her, the Doctor saw her die. Now that she's a professor, how long will it be before she takes that final trip to the Library and the Doctor will never see her again? River Song is his wife, and his time with her is limited. He can't even tell her that his hearts break every time she says, "Hello, sweetie," because he doesn't know if it's the last time she'll say it. After all, she can't know the ending to her story-"Spoilers."
The ghosts haunt the TARDIS, and haunt the Doctor. New companions only fill the void in his hearts for so long, etching their own space until they, too, must move on. Such is the curse of a time lord.