A/N: I suppose this is my way of dealing with the 5th season's final. Now, if you excuse me, I'll continue to beat myself up for not updating my other fics.
One heart feels strange, deficient, not right. How humans manage it, he'll never know. Not too well, apparently. If Rose is anything to judge by.
Rose is crying, her hand limp in his, unresponsive. Rose is crying because the Doctor is gone, her Doctor is gone, and John Smith who stands by her side is somehow less when he should be more. He simply can't measure up. Not to him. Not to her. Rose has grown so much since the last time he saw her... Only... Only he has never seen her. This is their first meeting.
And he is already in love with her. So in love with her.
And she doesn't love him back. His stranded, silly heart thrashes at the thought, thunders against his ribcage, struggles up his throat. "No," he says, "No. Look at me." She does, and in a way it's worse for in her eyes he sees the truth as clear as he sees the sun in the sky: he will always love her more.
Fair is fair. He tries to reason with himself that this is how it should be. After all the time she spent pining after the Doctor, this is only right. But his heart is unreasonable. It aches and aches and aches.
Rose is watching him, searching for the man he is supposed to be. He dares not to look away. He remembers her blazing, burning with the power of millions and millions stars, so brave, so selfless, so strong - how could he ever be enough? How can anyone ever hope to be enough?
His heart, separated from its counterpart, goes mad, goes rabid in his empty, empty chest. This emptiness, this new heartlessness frightens him. It seeps into the pit of his stomach and into the marrow of his bones; it uproots him in a manner which is both strange and sickening. He is nothing but air. Like a balloon set loose. He wonders if Rose feels cheated.
The Doctor's last glance is for him, not for her. 'This is a gift,' it says, and, of course, it is. Again, not for her - for him.
The Doctor can afford to be generous, even if it costs him, but John Smith with his lonely aching heart is a selfish man - he wants Rose all to himself.