Even by my standards, this review is heartily on the late side, so I will be brief. Basically, it’s marvellous. And it could so easily not have been. The last time Doctor Who took on Dickens’ venerable short novel, the results were disastrous for programme and leading man alike. Here, thanks in large part to a towering performance from Sir Michael Gambon, it works magnificently. In fact, this may have been the most completely successful Christmas special so far (read on).

The dilemma is a little contrived, but serves its purpose and is sketched in with admirable economy and finesse, including some cheeky visual nods to the recent Star Trek movie along the way. The key moment of “you didn’t hit the boy” is strong and simple and resonant, and the Doctor’s solution is a lovely Moffat-y mix of timebending paradoxes, jawdropping gags and just enough heartfelt emotion to paper over the cracks.

If you’ve ever wondered at the decorous ways in which leading ladies die gently and nobly of attractive diseases in movies-of-the-week (or even more highbrow fare such as Shadowlands), then you’ll be staggered at the way in which Katherine Jenkins faces imminent death with absolutely nothing in the way of debilitating symptoms beyond a very retro-looking countdown.

My only quibbles, disquiets or pauses are that Moffat Time Paradox stuff is threatening to become an over-used device – a sort of incorporeal sonic screwdriver. Next thing you know, they’ll be bribing the architect. Secondly, for the first time in ages, we were treated to some genuinely dodgy effects work during the shark-driven sleigh rides. It’s not even appropriately nostalgic, because it’s not fuzzy-edged CSO with parts of Matt Smith’s legs disappearing, it’s 1978 Superman The Movie-style visible matte lines, and actors happily lurching around, just not quite in tune with the changing angles of the background plate.

It’s also true that Amy and Rory don’t get much of a look-in, but to be honest that made sense. After the Doctor handling Sardick’s past, I had a horrible feeling that Amy would be handling the present at equal length followed by Rory somehow handling the future. In fact, the treatment of future was where all the timewimey stuff, the actual plot and the emotions of the story came together beautifully, and I’m sure Arthur Darvill will have more to do in the spring.

In short, what’s not to like? It’s complicated enough for the grown-ups, simple enough for the kids, it’s got a flying shark, the Singing Detective, an amazing acting debut from Katherine Jenkins, Matt Smith owns the part by now and it’s Doctor Who at Christmas. Five out of five. Easily.

Before I go, here’s a quick run-down of Christmas specials past. This is a short list since the only twentieth century episode which remotely counts is the bizarre The Feast of Steven also known as part 7 of the twelve part Hartnell leviathan The Daleks’ Masterplan. This demented entry, broadcast on Christmas Day 1965 features appearances from the Keystone Cops and Z Cars and ends with Hartnell wishing the viewers at home a happy Christmas. It no longer exists in the BBC archives.

However, following its triumphant return in 2005, a Christmas special was rapidly commissioned and almost instantly became a festive fixture.

The Christmas Invasion set the template while simultaneously introducing us to the definitive Davies Doctor. Absurdly Christmassey, or so it seemed at the time, it emphasised the audience’s existing relationship with Rose, Jackie and Mickey, deliberately keeping the new Doctor in the background until ready to give him a big entrance. And although David Tennant makes a huge impact in the last 15 minutes, the story is a bit ho-hum and the supposedly climactic sword fight is problematic firstly as a very physical bit of problem-solving for such an intellectual hero and secondly for some profoundly dodgy process work. The Doctor’s severed hand turns out to be the Christmas gift that just keeps giving however and the line “Don’t you think she looks tired” is just great – in fact the whole Harriet Jones goes all Brigadier on the Sycorax’s ass is a welcome shot of vinegar among all the sickly yuletide.

The Runaway Bride is absolutely amazing for the first twenty minutes or so (and I’m firmly in the pro-Donna camp). The motorway chase is one of the finest, most sustained pieces of dramatic, comedic and kinetic material that the series has ever offered. Through the middle, the puzzle of Donna’s boyfriend strains my interest and the revelation of the Racnoss is rather poor, thanks to the inexplicable decision to place poor Sarah Parish in a basically immobile spider suit and spray-paint her red.

Voyage of the Damned is the first of what became a cycle of temporary companion specials. Kylie is fine, but the concept of Doctor Who disaster movie feels wrong, and the whole is overblown and lacks focus.

The Next Doctor is two stories in one, neither wholly successful. The David Morrissey strand is nothing more than a slightly cynical headline-grabber from Davies. Next Doctor, my nutsack. This red herring is disposed of as quickly as is seemly, and we move on to Cyberman In The Snow which adds very little to the corpus. As with most of the David Tennant stories, it’s fun while it’s on, but it’s very short of the greatest that the series has to offer.

The Waters of Mars might have pipped A Christmas Carol if it had gone out at Christmas as originally-planned. It’s pretty-much perfect, but instead we got The End of Time Part One which if anything is even less coherent than the incredibly overblown second part.

As usual, the new series trailer had me salivating, so I’ll see you back here in the spring.