He watches her sleep every night, and whispers his apologies in her ear. Praying for a miracle that will never come. Her serene face is calm and empty of emotion, much like the expression in her eyes when she is awake.
He says he's sorry for what he's done to her, for what the years have turned her into. She listens but never replies, staring into the face of someone she once trusted, with thoughts of forgiveness and revenge engraved deeply inside her mind.
He holds her hand, and she pulls away, to sit as still as she can, for hours on end.
He smiles and she cries.
He breathes in freedom and she drowns in guilt.
Until one morning, he lies awake listening to the sound of her breathing, and hopelessness overcomes everything else. He packs slowly, quietly, until all his belongings are packed into a single bag, walking down the stairs towards the door. She awakes to the loud growl of an engine, and stares out the window to see him driving further away.
And she wonders whether it's her fault, or his.
The oddest and least sense-making one shot I have ever written. No doubt it'll fall into the giant library of HP fanfiction, and will never be read again. To anyone who reads this, it's based on a possible future Cho and Harry.