A/N: I love River Song. Every 'Who are you?' from Ten to Eleven makes me flinch.
There had been stars trapped in her heart since the very first time she met the Doctor.
The stars dazzled and so did she. She became luminous under his gaze. She was a beacon, a flare. She shined from within, feeling like she was fit to burst, buoyant and so completely free. Her heart tingled, sparked, sparkled and pumped star dust through her vein. She was everything, she was beauty itself when his eyes fell on her, twinkling with affection enough to drown in.
But now the stars are fire, burning and exploding over and over. Hot savage suns melting her. They overwhelm her. They become her. Beauty and light and the glory of life collapsing within itself as life burns itself down to ashes.
She is finally no-one. Unknown. She is nothing. It is not death that she fears. It's the shadows that blacken around her, the darkness of the star extinguishing at last. For now she doesn't exist, not for him, not for his stars.
"Who are you?"