River and Ten. He always says goodbye. Spoilers.

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The first time she meets him is on a beach in space.

The sea doesn't stretch very far – it ends about six miles out, water falling into oblivion. The tide never comes in so the beach is more a collection of large jagged rocks with some water halfway down. It's not a place you would find anyone – anyone but a timelord.

She sees him standing by his TARDIS alone. In her younger days, she would have ran towards the Doctor, maybe pointing a gun with an outbreak of laughter. She's older now. The strains of mortality have matured her; it's one of the reasons why she thinks the Doctor acts as childish as he does.

Acted. She's not sure if this regeneration is like his next.

"Hello, Doctor," she says, stepping into her place beside him.

He gives her one glance. "River."

She takes a pause to study him. He's taller – much taller – with dark eyes and no baby face and a great big trenchcoat that makes him look all impassive. This face would be an angry face, if he didn't look so sad. It unnerves her, a bit, to see him just so sad.

She might as well get used to it.

"So, what's a great adventurer like the Doctor doing all the way out here?" she asks, smiling. (Smiling is too nice a word; the only word that appropriately describes her expression is in a language that human vocal cords find unpronounceable.)

He doesn't answer. She falters slightly, thinking she might have misjudged this regeneration.

"You should leave, River." He says gently.

She laughs. "No." She replies. This is one of the coincidences in all of space and time when they have come across each other. When she sees him next (as she always will) he will be younger yet and she will be so much older.

(In the spaces in between when she meets him, in the long years that go by without a word, she thinks of the day when the Doctor will not know her at all. What is she supposed to do, when she reaches the end of the Doctor's life?

(deep, deep down in her heart, she knows she cannot last that long. the first time the Doctor meets her will be the day she will die.))

The Doctor sighs and turns away, back to his TARDIS.

"Goodbye, River," he says and is gone with a sweep of his coat.

She stares after him.

In time, she learns that his tenth will always say goodbye, while she knows that they will meet again.