Spoilers for the Pandorica Opens.
I'm not trying to predict what happens in the last episode. This is merely just a character study of the Doctor.
Unfortunately, that was the truth. Staring at the Pandorica, the one thing that he didn't know in the universe, the one thing that had followed him and haunted him throughout this incarnation, the something that could very well end the world in less than a second, he had told River and Amy about the terrible thing. It was just a legend, cast out into time and space. He'd heard bits and pieces, scary stories like the Toclafane to stun the children of Gallifrey into obedience. But for that split moment there was a hesitation in his mind. Because it was all falling into place. And for a split moment there… he thought he himself was going to end the world.
There was a goblin or a trickster or a warrior.
Because that's how it always is, isn't it? The Doctor comes in, he fixes everything, but he leaves a trail of bread crumbs in his wake. Bread crumbs that could be debris of falling buildings, or the rotting smell of corpses.
A nameless, terrible thing soaked in the blood of a billion galaxies.
He pushes the possibility out of his pride-filled head. Of course it can't be him. There were plenty more malicious races out in the universe –and they were coming to Stonehenge. That was the priority. There was no time to lose. Ironic how the Lord of Time was fighting against time itself. So his pride blinded him from thinking. Coincidences, Amy's childhood. Everything seemed to fall into place… and then there was Rory. The one thing that stuck out. The one thing that the Doctor should have notice immediately. He scanned Amy, why didn't he scan Rory too?
Because he was too happy and prideful.
The most feared being in all the cosmos.
What was it River had told him? That he couldn't fight it? Because it was everything in the universe that despised him. And for once, he was the enemy. He was the one that needed to be eliminated. For once, the tables had turned.
There was a joke too. Amy asked and he told her about the "wizard." Him of course, at least that's what he thought.
Nothing could stop it or hold it or reason with it.
Autons. The Romans were autons, which of course explained Rory and how Amy was in grave danger. Which of course explained why the TARDIS was acting up and how, possibly, the TARDIS was going to blow up.
This was his final defeat wasn't it? The final end. The only end. The non-existent end. Because if he's in that Pandorica, then there was never a Doctor, never a Last Time War where the Time Lords were locked, Leadworth would be the city that time forgot and… and…
The Doctor smiled mentally as the walls finally snapped shut, locked inside the Pandorica so he never did and never would and never will have existed. Never met Amy, never met Rory. No Amy means she shouldn't be at Stonehenge. No Amy meant Rory didn't die. No Stonehenge, no Rory. It all fit together, like pieces of a puzzle. It meant… it meant that there was never this ordeal with the Pandorica. Amy would have never been here for his enemies to use as an unwilling asset. No Roman project –no autons. No Pandora's Box fairytale book –no Pandorica itself. A paradox within a paradox within a box.
All the Doctor had to do was find a way out and he could fix it… Maybe.
One day it would just drop out of the sky…
Inside the black box, under Stonehenge, in 102 AD, a maniacal laughter echoed.
…and tear your world down.
In England, a young ginger girl –barely seven- stumbles across a black box. She hears the laughter.
And just for the point of it...
Poor Amy and Rory!
Looks like Karen Gillan really meant it when she said Rory was dead and wasn't coming back.
Because it technically wasn't Rory, even though he resisted.