He's alone at the end.

No Companion, no Time Lord, not even the TARDIS. She stands behind him, dead, broken, paint peeling, like any other disused Police Phone Box on Earth millennia ago.

It's quiet. He can't hear anything in the increasingly long stretches of time between his twin heartbeats.

In the silence the light tread and whisper of cloth is shockingly loud, before the man appears before him.

He's not tall, though he looks it. His movements are smooth and precise, inhumanly graceful. And he does look achingly human. He misses the humans.

Whatever this creature is, he isn't human. It's in his eyes, as old and knowing as any Time Lord. Impossibly green, like something out of a dream.

The Doctor is suddenly reminded of human legends - the Grim Reaper - and would have laughed if he could. It strikes him as kind in the way only humans occasionally could be (to balance out the cruelty, he supposed), that despite his lack of humanity, and the disappearance of theirs, one of their legends had chosen to visit him.

Not that the Visitor, whoever he is, seems Grim. He's serious, his mouth a firm, neutral line. But there's kindness in those unnatural eyes.

His hearts thud painfully again, and he can't speak, but he asks the question with his eyes, flicking them up and down.

The corner of the Visitor's mouth curls ever so slightly into a smile he never completes.

Instead he speaks in a low voice, like a symphony in the unbearable quiet. "You were alone."

He doesn't say anything else and he doesn't need to. It makes sense. A final Companion. And the Doctor has done his best never to leave anyone alone.

He manages a nod in response, just able to tip his head. It hurts and his grip on the world loosens, tightening his chest in fear.

It's absurd, really, hypocritical after everything, after the Time War. He'd never thought he'd be afraid at the end, always knew it would happen eventually.

He never thought he'd be afraid of the Unknown, when every other Secret of the Universe had already been laid bare.

The Visitor must see the fear, as those implacable eyes soften and he's crouching down at arms length. For a moment he seems a lot more human.

"It's a journey," he says with that arresting voice. "It's moving on."

The Doctor has a sudden, intense mental image of a bright red steam train, the sort that had delighted him when they first appeared on Earth and disappeared all too soon.

And the Doctor feels something loosen with relief inside him. He smiles - it's suddenly easier, he can even move enough to uncurl his fist. Reading his mind, the Visitor takes his hand immediately, feeling surprisingly warm and steady.

They've called him the Doctor. The Oncoming Storm. Even, obscenely, a hero.

But really, he is and always has been a Traveller.