In the end, all it takes is a moment to press a few simple keys in a university library.
He sits on a bench beside one of the main thoroughfares of the Galactic University on Ambrosia Axis Eleven and watches students walk by in their pressed uniforms. Her image, smiling as she greets her fate, sits before his heavy-lidded eyes.
Would you choose that, River?
I saved you once, I can save you again.
What would you want, my River?
The answer is easy, so he ignores it. His River chose him, always and forever. She already has. Would have.
In one reality, a twenty-year-old girl named River Song turned a corner on her way to class and tripped over an absurd man wearing an ancient bowtie and a straw hat. When she ran with him, she never looked back.
In one reality, a twenty-year-old girl named River Song found that her application to Honors Cultures of Primitive Earth had been rejected, and took the regular class instead, on the other side of campus.
His head lifts as she walks past, arm in arm with the handsome boy she will someday marry. She turns and catches him staring. She tilts her head a little, confused, and offers him a small smile.
Her boyfriend says something that distracts her, and she turns away. She won’t even remember having seen a strange man in tweed and a bowtie today. She will go on to be a renowned archeologist, famed for her impressive understanding of prehistoric planetary cultures. She will be happy.
He feels so, so old as he pulls himself to his feet and walks back to the TARDIS. When the door closes behind him with a soft click, he rests his head against its door and whispers, “Where to now, old girl?” as the memories slowly fade away.