50 years after Doctor Who was first broadcast, almost to the moment, how fitting to begin this anniversary special with a reprise of 1963's opening titles.
Continuing the link to the past, the first scene of "The Day of The Doctor" echoed that of "An Unearthly Child", with a local bobby walking past the famous 76 Totter's Lane address. Oh, but look: the scrap yard where we first met The Doctor has since been demolished and replaced with a school.
Clara, who has since become a teacher (mirroring the fact the first companion, Susan, was a schoolgirl?), races to the TARDIS on a motorcycle and roars inside. It's an impressive visual effect, that always reminds me of a similar one in the 1996 Doctor Who TV Movie.
The TARDIS gets airlifted to central London by UNIT, which struck me as a little random, but it made for a great visual and real-world stunt.
It's Kate Lethbridge-Stewart and her assistant Osgood at the Tower of London, wearing a familiar long scarf. I wonder if the Fourth Doctor left that in a UNIT vault and Osgood took a fancy to it...
A shot of the TARDIS, suspended from a helicopter, about to touch down in Trafalgar Square. Glorious.
One of the snazziest 3D effects was the incredible depth of the "Gallifrey Falls" painting, depicting the Last Day of the Time War.
And now we're back in time, where The Doctor's greatest adversary, the Daleks, are assaulting Gallifrey's second city, Arcadia.
Ooh, look! There's Star Wars-style cityscapes and spaceships! Zap! Pow-wow!
Our first look at some Gallifreyans since Timothy Dalton spat at audiences in "The End of Time". They have a rather awesome holographic battle map in their War Room.
More of the film-quality special effects, as dozens of Dalek ships arrive in orbit around Gallifrey and begin bombing the cities below...
Our first look at John Hurt's so-called 'War Doctor', appearing out of the heat haze of a Gallifreyan desert. He's seen terrible things, but wants to prevent further bloodshed by triggering the "galaxy eating" Moment--an Ancient Time Lord doomsday device.
Oh, but who's this? Rose Tyler! Or, rather, a projection of her the sentient Moment's created to interface with the War Doctor.
At the National Gallery, The Doctor recognises a familiar face of his own -- his Tenth incarnation, painted onto a canvas alongside Queen Elizabeth I.
Now we're back hundreds of years to Elizabethan England, where a Fringe-style floating legend reveals it's 1562.
Alons-y! It's the Tenth Doctor himself, out on horseback with the Virgin Queen.
Unfortunately, The Doctor and The Queen's picnic is ruined by a gooseberry shape-shifting Zygon disguised as their horse.
"Ohh, very clever. Whatever you've got planned, forget it. I'm The Doctor. I'm 904 years old. I'm from the planet Gallifrey in the constellation of Kasterborous. I'm the Oncoming Storm, the Bringer of Darkness, and you... are basically just a rabbit, aren't you?"
CLARA: Someday, you could just walk past a fez.
THE DOCTOR: Never gonna happen.
Can you hear the fans squeal at the sight of David Tennant wearing a Matt Smith fez?
That's it! That's what we've come to see: two Doctors and a pair of Queens. A winning hand.
Both Doctors are delighted by each other's eye-wear.
It's the sonic screwdriver 'is yours bigger than mine?' test, known to all schoolboys after P.E.
WAR DOCTOR: Good afternoon. I'm looking for The Doctor.
DOCTOR TEN: Well... you've certainly come to the right place.
WAR DOCTOR: Good. Right. Well, who are you boys? Ohhh, of course! Are you his companions?
DOCTOR ELEVEN: His companions?!
WAR DOCTOR: They get younger all the time. Well, if you could point me in the general direction of The Doctor...
Clara is taken into the TARDIS-proof vault, where she realises all companions are spied on by UNIT. Can you spot any easter eggs on the board? I think I can just about make out Amy, Rory and Wilfred in some photos.
It's a vortex manipulator, as worn and used by Jack Harkness.
When face-lifts go bad? No, Kate's actually a shape-shifting Zygon! Excellent effects for the transformation.
The Eleventh Doctor is a big fan of sending SOS message through time, by carving things into old stone, isn't he? He does variations on that a lot.
One of the funniest moments was seeing the Three Doctors devise a genius plan to have their sonic screwdriver's software spend 400 years calculating how to destroy their prison door, only for time-travelling Clara to step through it because it wasn't even locked.
So that's the Zygon plan: hide inside oil paintings, Trojan Horse-style.
This was another hilarious nod to the fact latter-day Doctors do a lot more kissing than the pre-War Doctor's incarnations are used to.
We're back aboard the Tenth Doctor's TARDIS, unseen since... well, "Journey to the Centre of the TARDIS" earlier this year, but it's still fun to see.
DOCTOR ELEVEN: Eh, look - the round things.
DOCTOR TEN: I love the round things.
DOCTOR ELEVEN: What are the round things?
DOCTOR TEN: No idea.
DOCTOR TEN: Ohh, you've redecorated. I don't like it.
It wouldn't be Doctor Who without a countdown to total destruction, now would it?
It's time to go back to the Time War, but this time The Doctor's bringing backup. Himself, times two.
The present-day companion, Clara, reads about the first companion, Susan.
The War Doctor gets his 'big red button' wish.
A little cameo from a Cyberman, The Doctor's second most prolific foe.
Three Time Lords have a big decision to make...
The Doctor pulls in reinforcements: all his incarnations, seen on the viewscreens in the War Room.
And by all, I mean all: it's Peter Capaldi's future-Doctor, officially referred to as the thirteenth incarnation...
Thirteen TARDIS descend on Gallifrey to rescue it from annihilation.
A lovely shot of the three TARDIS. TARDIS's? TARDI?
Farewell, War Doctor, we hardly knew ye...
Anyone else extremely frustrated this regeneration didn't herald a surprise cameo from Christopher Eccleston's Ninth Doctor? That would have been the cherry on the cake, continuity-wise...
Oh, but we did get a surprise cameo! (If you don't read tabloids) It's the legendary Tom Baker, back as the Fourth Doctor. Or, more accurately, a future incarnation who appears to have retired and become a museum curator with an old face. A little nod that the 'twelve regenerations' rule will be broken? It's good to see Baker, who is undeniably the most popular Classic Doctor.
Now this is lovely. Through the wonders of modern technology, all eleven Doctors are united on-screen, with the First presiding over his descendants on a cloud. Beautiful.
And what a lovely touch crediting every actor who's ever played The Doctor.
The decision to have every Doctor's face push out into the audience was also really nice, beginning with the Doctor who started it all: William Hartnell.