The Doctor takes a yuletide trip into the darkness of a heart...

If you want to see a giant flying shark pulling a hansom cab of Christmas revellers over the urban landscape of an alien city that's half-Dickensian and half Philip K. Dick, it's Doctor Who or bust.

Show-runner and writer of this year's Doctor Who Christmas special Steven Moffat has plundered Dickens' 'A Christmas Carol' with imagination, wit and a sense of wonder, giving us the best yuletide outing for the show since it re-booted in 2005. And if the Beeb still can't afford a music editor to inject the occasional moment of silence into Murray Gold's sugar-coated soundtrack, and if the shark still looks fake (why is it that no amount of money in Hollywood or beyond can create a convincing version of this creature?), and if we note that The Doctor could simply have travelled back further into Amy and Rory's doomed honeymoon cruise instead of spending 20 Christmas eves trying to give futuristic despot Michael Gambon a heart so that he would let the ailing craft land safely... well, these are uncharitable thoughts, particularly at such a time of year.

The genius of Doctor Who's 'A Christmas Carol' is how much further it deviates from Dickens' tale of miserly redemption than the trailers might have indicated. The set-up takes only minutes to establish: Amy and Rory are about to join 4000 other cosmic cruise-passengers in a fatal crash into a snow-encircled planet colonised by humanity. The clouds that are going to send the vessel to its demise have an unusual constitution that responds to sound and hides a vast sub-culture of electrified, floating fish, predators and prey alike. Only overlord Kazran Sardick (Gambon) can control the clouds and save our heroes, but he's too bitter and twisted to do it.

Thus does The Doctor set off on a Groundhog Day-style journey of taking the younger version of Sardick through decades of Christmas eves in the company of the frozen 'loan collateral' played by singer Katherine Jenkins. The young Sardik and the one-day-a-year conscious Jenkins fall in love through the years of Christmas eves.

And here the folly of pre-temporal interference comes into focus, as the new path on which The Doctor has taken Sardik proves just as damaging and painful as the one that led him to be a heartless miser in the first place. For young Jenkins has put herself forward as loan collateral for her family knowing that she has just eight days to live, which will be extended indefinitely in the suspended animation chamber in which she is held hostage against the loan.

This would work nicely except that there is a counter on Jenkins' sarcophagus that ticks off the few days she has left, thus making her pretty valueless in terms of 'security' against a loan for Sardik's father (also played by Gambon). The shame of it is that it's a needless goof for the sake of a visual narrative device that lessens the shock of finding out that Jenkins is ill, and actually telegraphs the plot-point. But it's still a neat deviation from the standard formula of ghosts past, present and yet-to-come.

What was truly refreshing was to see not only that the controversial 'psychic paper' is now broken, but that the sonic screwdriver is at least in peril too, having been cut in half by a flying shark. Thank God for that - hopefully Steven Moffat has more interest in solving plot-obstacles than his predecessor, who loved a 'get out of jail free' card.

Additionally (and if you haven't clicked that there are major spoilers in this review, be aware now), Moffat actually finds the courage to do what Russell T. Davies hardly ever did - to kill a sympathetic character. And on Christmas eve, to boot. But not for the sake of sadism or ersatz sentimentality, but rather to make a point about life being more about the journey than the destination. Today, someone dies. But not in vain.

'A Christmas Carol' wasn't without its requisite quota of laughs either, particularly once Matt Smith settled down from an unexpected David Tennant-style burst of exposition at the episode's beginning and returned to his own take on The Doctor. Smith's unthinking revelation to a 12 year-old boy about the truth of there being monsters in his bedroom was rib-tickling, while the actor, in concert with Moffat, re-emphasised the alien-ness of the Time Lord as the sexually-neutral eccentric that he was back in the old days.

The visual effects work was, as usual, more dazzling in the recreation of a large (if retro-style) future society than in the more difficult depiction of monsters and creatures, but the 'cloud-fish' that gather and swim around the Victorian-style lamp-posts were beautifully depicted - a charming and magical idea that at least had some kind of perfunctory scientific explanation, done full justice by the visual effects team.

And the dads got to see Karen Gillan back in her 'stripper-cop' mini-skirt uniform, so that's pretty much all bases covered in terms of ratings.

Finally, we got a look at the Arizona locations of next spring's season six, with a glance at the Ood and the return of Alex Kingston as River Song. The editing was too choppy and sleight-of-hand to do more than tantalise, but on the strength of 'A Christmas Carol', roll on 2011.

See also:

Doctor Who complete reviews: A Christmas Carol

DOCTOR WHO COMPANIONS: THE ULTIMATE TOURNAMENT

MATT SMITH - THE BEST 'DOCTOR' SINCE TOM BAKER?

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