1. WHO IS THE CURATOR?

Given that Tom Baker sets up the arc for Series Eight – the hunt for Gallifrey – it seems far too significant to be a mere tip of the hat to Doctor Who’s history.

Obviously, mystery is good for this show – despite the fact people spend most of the time complaining that Doctor Who has too much of it, they used to complain there was far too little – and all theories are equally valid.

TARDIS roundels on the walls and the fact that the Curator doesn’t actually tell 11 anything he doesn’t already know – he merely reframes it and ushers him along to comprehension – definitely suggests that he’s merely a figment of the Doctor’s unconscious. Everything he says is directly prompted by 11, so the idea that he could retire and become ‘the Great Curator’ is met by an image of that very thing – it doesn’t necessarily mean that’s what’s going to happen. Since when has the literal interpretation of what’s said in Steven Moffat-era Doctor Who ever been the case? When is it every as simple as all that?

The way it was shot – the Curator walking off into a bright light – looked exactly like Dumbledore’s conversation with Harry Potter in The Deathly Hallows Part 2.

2. HOW COULD CLARA SEE HIM, THEN?

Maybe she didn’t, maybe the Doctor imagined that bit of the conversation too, or maybe her gallivanting up and down the Doctor’s personal time stream in The Name Of The Doctor makes her sensitive to such things.

2. WHERE WAS RASSILON?

Surely if Gallifrey never fell then the Time Lords wouldn’t have driven the Master insane, unleashed their doomsday weapons and set in motion Ten’s regeneration in The End Of Time.

However, we only see Arcadia – Gallifrey’s second city – so maybe the High Council and the loyalist Time Lords set their plan in motion before the Doctor resolved things. Maybe Gallifrey did briefly blink out of its rightful place in time and into Earth during the invasion – either earlier than the Fall of Arcadia, or during – leaving Rassilon free to be a large, scenery-chewing ham off screen.

In fact, as the nature of the Time War caused “millions [to] die every second… With Time itself resurrecting them to find new ways of dying, over and over again” perhaps the 13 Doctors are constantly at battle out there, sometimes dying and failing, sometimes totally victorious. It’s a nice idea, and leaves the Time War ripe for constant revisitation.

3. IS THE MASTER STILL ON GALLIFREY, THEN?

The Doctor’s dialogue in The End Of Time seemed to suggest that he had been removed from play well before then: “You weren’t there, in the final days of the war.”

4. DID THE TIME WAR REBOOT EVERYTHING?

Not in the slightest. In the original timeline, the Daleks were wiped out (mostly) and Gallifrey was destroyed. In this new timeline the Daleks were wiped out (mostly) and Gallifrey was believed destroyed. With the Time Lords frozen in time, all the things that happened (or didn’t) in the show since 2005 because of their absence continued to happen (or not happen).

5. WHY CAN’T THE OLD DOCTOR REMEMBER THIS?

The Doctor may be outside time to a certain extent and able to remember things like, say, Rory falling into a Crack, but time heals from paradoxes like this, otherwise crossovers would be very short indeed, as every successive Doctor hurtles toward the end point, having seen it all before.

When they go their separate ways at the end of ‘The Day Of The Doctor’, it all gets a bit fuzzy. The War Doctor (“I won’t remember, this will I?”) regenerates, knowing only that he’s alone in a cold, uncaring universe and that he’s responsible for the loss of Gallifrey.

We’re not suggesting that this is the case, but strict applications of time travel theory would suggest that for each Doctor involved, their future now unravels differently as a result of moving along a different timeline. So the Ten that teams up with 11 isn’t the same Ten that becomes the 11 he teams up with; he regenerates into a different 11th Doctor who makes different decisions, constantly splintering off.

Time travel, people!

6. HOW CAN 11 REMEMBER, THEN?

We don’t know how much of it he can, yet…

7. WHERE DOES THE FEZ COME FROM?

Onto the important stuff, eh? 11 picks up the fez and shoots it back in time where it is then placed in Elizabeth I’s collection of secret Doctory things – so it has no beginning point, it exists in a complete loop. However, the original fez might have been destroyed in a fire (for example) and then sneakily replaced.

Let’s throw all our eggs in one basket and say this was the fez from Silver Nemesis – that one was being held in the cellars at Windsor Castle – and it would be a nice callback to the 25th Anniversary story, wouldn’t it?

8. WHY DID THE MOMENT LOOK LIKE ROSE?

Time Lord technology has as fluid a relationship with time as Time Lords themselves, the weapon with a conscience just chose a form that it knew resonated with the Doctor and Bad Wolf, itself being a timey-wimey energy weapon thing was probably the most vivid imprint of galaxy-shattering destruction the Moment could pick up on.

Best of both worlds, something he would listen to and something he knew to be powerful… er, one day.

9. WHAT WAS GOING ON WITH ALL THOSE TIME LORD FAMILIES? SURELY THE LOOMS…

Don’t you dare.

The 2013 Doctor Who Christmas Special will air 25 December 2013 on BBC 1. Pick up the Doctor Who Series 7 box set on DVD for £34.50 or Blu-ray for £36.33 from Amazon.co.uk.