"Time can be rewritten," he said to himself, aloud once, a very very long time ago. He hoped that she hadn't heard him say it, because only now did he understand some of how she suffered. It had become his turn to watch her know him less and less each meeting. To prepare to die before her.
His misplaced hope didn't lessen the truth of the statement. Time could be rewritten. He rewrote it himself frequently, habitually. It was easy to turn one watch's cog at odds with the others and marvel as time stopped, briefly, then unwound itself.
Last time they met, he had been the one to have to suggest they compare diaries. She fumbled for it in her archaeological gear, unused to retrieving it on demand. Eventually it appeared, very blue, the spine unworn and not a single mar on its cover.
He had been the one to inquire, "Have you met Jim the Fish?" and "Have we been to Easter Island?" He felt old, even older than usual when she responded by asking who and what and when that had been.
"Sorry, sweetheart, spoilers." He wished he could maintain her past self's (or future rather) lightheartedness when speaking the familiar phrase. He forgave himself with an illogical excuse, "Her time did not have to begin with watching me die." Immediately he'd admonish himself. They both had, will, and will always suffer.
"When have we met then?" he asks somberly, not quite meeting her concerned gaze. He fails to stop her from answering, too bitterly disheartened, before he realize what her reply would mean.
Her forehead cinches in puzzlement as she asks, "You don't remember saving me after I stole the Magnatine Dynasty crystals from the Delerium Archive?"
His hand gently cradled his forehead as he sighed deeply. "I do now." He tries to smile genuinely but can't.
Now aware of a destiny he had tried so hard to escape, he journeys to that time, that place of their first meeting. He had hid from it with his rules-never read the blue diary, never cross your own timeline-and he'd long out run it, but destiny had finally caught him. As much as he fought time, he was still it's servant.
He arrived at the Delerium Archive halfheartedly, the TARDIS soundlessly lands someplace near the stone steps leading to its entrance. A crowd of intergalactic tourists gawk at a girl in white running, strait blonde hair a halo around her pale face as she blasts her way through a door, through security; anything in her path. The Doctor pushes quickly to the front of the crowd, muttering "excuse me" in a hundred different languages. A black-clothed guard on a hover-board trains a gun on her and fires, a green light hitting and absorbing into her ankle. She stumbles but does not cry, instead whipping around to point her at the guard.
He had been thinking for some time, "Time can be rewritten," and as he returned to this conclusion he was angrier than before. The suffering, the lies, the truth of what she was, the death-it could all be rewritten. If anyone could rewrite it, he could. He pulls the sonic screwdriver out of his pocket and flips a switch. A spark is the only indicator that her gun has been disabled. He turns and strides away toward the TARDIS, hearing her faintly screech in frustration at the realisation she has been failed. As he swing open the blue door, he feels a light tap on his forearm. He turns to see a small humanoid girl wearing a white sundress despite the great cold. He glares at her, beging silently for her to leave.
"Sir?" she pleads.
"Yes."
"A man in a silly red hat told me to say to you that 'the clock has been rewound'" He glances at the steps of the archives to see a horde of guard frantically searching through the crowds and a very blue box appear in the skies behind the archives. He immediately looks away, down at the girl.
"What does it mean?" she questions. A true smile spreads across his face.
"It means everything. And conversely, it also means nothing at all. But at this particular moment in time and space it means, approximately, 'till death do us part."