So, people have been asking what this Doctor Who thingy is. For those who don’t know, here’s a link to a detailed explanation. Those who just want a five minute primer to explain what they’ll need to know before tonight, read on.
A long time ago in a galaxy far, far away…
There lived a society of beings who had advanced science to degrees far beyond our own, to the point that the games their children played would seem like magic to us. These people, at the height of their civilisation mastered the manufacture of black holes, and were able to contain them and use them as a power source. This led to them being able to master dimensional engineering and finally time travel itself. Over time these time travellers became sensitive to time, knowing instinctively when things may be changed and when they were in the midst of a fixed event which must not be changed. They were the Time Lords.
A great culture rose on Gallifrey, the planet of the Time Lords, and many changes occurred within them. The Time Lords split their culture into two distinct parts, the scientific who became the Time Lords and the religious who became the Sisterhood of Karn. The Sisterhood developed a camouflage elixir from their Sacred Flame that allowed them to change how they appeared on the outside, but this required great amounts of energy pull off. The Sisterhood shared this energy with the Time Lords, and eventually the elixir caused the Time Lords to be able to change at will. When a Time Lord is mortally injured this energy is released and it changes how they look and even some parts of how they think, rewriting every single cell. They’re still the same person deep down, with the same memories and drives, but they’re different in how they react, speak and look. This is known as regeneration and Time Lords have a limited amount of them that allow them to effectively cheat death. The Time Lords could award new regeneration cycles (twelve regenerations worth of regeneration energy) to people who earned them, usually with the help of the Sisterhood of Karn.
At some point one of their member, a man whose true name is unknown, decided to go for a wander around time and space. He stole an old and faulty Tardis (one of the time machines the Time Lords had developed) and left Gallifrey with a girl who thought of him as her Grandfather. Landing on Earth in the 1960s, the newly christened Doctor hid a Time Lord relic in a scrap yard and put his granddaughter into school while he tried to fix the broken Tardis. Amongst other problems its chameleon circuit (which enabled it to look like anything as camouflage) was broken and it got stuck looking like an old police telephone box.
He was discovered when his granddaughters two teachers thought she was strange and followed her home (because teachers were a bit creepy back then) and left that time period along with his granddaughter and both of the teachers as prisoners. They had a few adventures, meeting aliens and monsters, demons and eternals, and the Doctor used his mind, a piece of string, his sonic screwdriver and a lot of deus ex machina to overcome most of the problems. Every couple of years a companion would leave or a new one would be added. Occasionally he’d be wounded or poisoned or grow old, and he would regenerate. And sometimes, just for the sake of it he’d change the theme of the Tardis, making the control room look different than it had previously.
After being put back in contact with the remaining Time Lords, the Doctor was tasked with stopping the Daleks (a race of xenophobic mutants who wanted to destroy all other species) from developing. He hesitated at the thought of committing genocide and only set the Daleks back, but not before they knew who and what he was. He continued to cross them in different ways, stopping their plans and generally annoying them, which is never a good idea with psychotic mutants. He even let them find the Time Lord relic he’d hidden and tricked them into using it, destroying their home planet of Skaro in the process.
What really complicated things is that the Daleks were one of the few other races in the universe to develop time travel. Their version was not as reliable as that of the Time Lords but was way ahead of the few other races who had developed a version of it. Spurred by their almost extinction and the idea of what they could do with the power of the Time Lords, the Daleks attacked and warred for time itself. The war was brutal, with each side using their knowledge of science to create monstrosities to tip the balance. Whenever a side suffered great losses they would use time travel to change the outcome. Entire worlds were wiped away in the waves of the paradoxes created by these constant resets and it went down in legend as the Time War.
So here we are approaching the anniversary. We don’t know the true name of the Doctor, nor do we know why his name has been kept a secret. We do know that he was the one to end the Time War, locking his home planet away forever with an artefact called The Moment. We know that there is a dark side to the man, an incarnation who did something that made him hide his own name away, and we know that the Sisterhood of Karn were instrumental in bringing that dark side about. We know that he tends to run into past versions of himself on anniversaries. And we know that the two companions who will feature prominently in the anniversary movie have both travelled through his timeline for different reasons so may not be showing up as their regular selves.
So now you’re pretty much all caught up on what you need to understand the Day of the Doctor.