All these long years - even before the Time War - you've laboured under the idea that there were things that had to be fixed points in the Universe. The Daleks had to exist. The Time Lords had to die out and the War had to be left as it was. The development of nuclear weapons on Earth couldn't be halted or interrupted. Even on the small, unimportant levels, there are things that had to happen. Rose had to go over to Pete's World. You had to leave Donna behind, as the person she wasn't.
All these long years, you've let tragedies play out around you, convinced there's no other way.
Listening to the panic in the base, to the shouts and screams of the team (well, what remains of them) you wish you could help them. You're sick of standing by and just watching as worlds fall to pieces under your gaze, as the Universe tears itself apart under your steady watch. As the people you love get lost in all of this, and end up leaving you.
But you have to keep going. You have to move on. It hurts, so badly, knowing you could help but being bound to a law that commands you not to. You don't want to leave these people to their death, but deep down inside a part of you knows you have to. The first step is like torture, like shards of glass cutting every inch of you. The next one is just as painful, but you try and numb yourself to the pain, just like you've learnt to.
The rockets of the ship fire up. Over the intercom, they sound so hopeful and this hurts more than anything because you know they're going to fail anyway. Still, you keep walking, forced but resolute steps, away from the base. You hear Roman die but you still you make yourself keep walking, trying to ignore the fresh wave of pain. Next it's Ed, and with him, the ship. The blast rips the base open and you go flying, headfirst towards the flaming debris and Martian soil.
And that's when it happens.
It's like a switch is flicked in your brain: something small and seemingly irrelevant changes.
Why not go back?
So simple a thought. So basic a concept.
Why not save them? Why walk away when you can help?
It's elemental. Animal. Instinctive.
There's nothing stopping you. Nothing at all....
And it's right.
The Daleks died. The Time Lords died. You didn't - you survived. You won. Why should you keep to the rules of a dead society when all they do is cause you pain beyond imagination? All the things you could have done, all the lives you could have saved if only you'd discarded the rules. All those people that would still be alive... All the places that would still exist.
The Time Lords died. You survived. All these years, you've kept clinging onto those rules you hated, for ... for what? You can't remember why. All the justifications you've been giving to yourself for abiding by the old laws don't seem to consist of anything other than nonsense. It's with a jolt you realise you've hardly changed since the Time War. Whatever happened to adaption, to change, to moving with the times?
The Time Lords died and you're the only one left. Why should people have to suffer for the decaying rules of a dead civilisation? Rules that you don't even believe in. Rules that tear your hearts and your mind into pieces every time you obey them. Rules that don't even need to exist - the Universe can change enough to fit the details together. The story ends up the same overall, but the tiny details can change. You see it all in your mind: all that could be, all those people saved, all that pain taken back. All because you helped. And you can help. The power of time and space lies in your hands and no one can stop you because that's all the power you need. You turn to face the base again, and start walking back with the steely determination of a changed man.
You are changed. Now, you know you can save them. You're not just the last of the Time Lords: you're a Time Lord victorious. And you have the power to do anything.