And he found a letter.
After everything that had happened he found a letter.
Tucked away in her room never meant for his eyes, never meant to be read.
But this letter traveled the skies, the stars, all of time.
This letter had been so many places, seen so many things.
This letter had lived.
He unfolded it slowly, desperately.
It let out a breath of life.
One small gold wisp of life, from the Tardis, from her.
He read the letter and smiled, secretly dieing inside.
Infinity stopped for a moment and was suddenly so small, so unimportant.
The letter, the letter filled with so much life, said only one sentence.

And we will find life amongst the stars, forever together.

And he realized that day that they had.
Traveling, saving worlds without ever making a difference.
They had altered time forever without changing anything.
Now he was left alone, to search for new air to breathe.
As if that would ever keep him from suffocating.