It's difficult to get the Cybermen right. In the pantheon of Doctor Who monsters they've always been the Penguins to the Dalek's Joker, a second tier threat that requires a deft touch to work. Well, touches don't come much more deft than Neil Gaiman, and in his second episode he's served up a belter.
Following the end of last week's episode, Artie and Angie, the two children Clara looks after when she's not jaunting around time space, discovered that their nanny has appeared in photos throughout history. Her secret life as the Doctor's companion thus revealed, she's blackmailed into letting them take a ride in the TARDIS. The Doctor, being a big kid at heart, opts to take them to Hedgewick's World of Wonders, the biggest amusement park in the universe.
Unfortunately, when they arrive the place is deserted and falling apart, having been abandoned following the Cyber War in which the forces of humanity finally defeated the Cybermen by destroying an entire galaxy. Instead they meet Mr Webley, a curious man in a top hat, hoping to be rescued from this desolate rock that's home only to a “punishment platoon” of soldiers too crappy to be allowed near active service.
Webley shows the Doctor, Clara and the kids around his own “world of wonders,” mostly made up of low quality waxworks and three supposedly empty Cyberman shells, one of which has been rigged to play chess. It's a cute nod to the real life chess-playing automaton “mechanical turk” which wowed high society in the 18th century. Much like the turk, Webley's machine is also a fraud, controlled from within by a man called Porridge (Warwick Davis).
Of course, we know that once you have the Doctor in close proximity to the Cybermen – even hollow shells – things are going to turn ugly, and they do. Tiny “cyber-mite” units have been watching and waiting for a suitable brain to arrive on the planet, and soon enough poor old Webley has been assimilated, a sleek upgraded Cyberman is on the loose, and it's used super-speed to snatch away the two kids. Their young brains are perfect to reboot the cyber-consciousness, but then they scan the Doctor's Gallifreyan brain and decide he's much more useful. Among the upgrades to cyber-species is the ability to assimilate non-human tissue, and before you can say “Evil Dead 2” the Doctor is half-possessed by the Cyber Planner and forced to outwit an enemy that has taken root in his own brain. Their chosen battlefield? Chess, naturally.
What follows is a spritely mixture of traditional Who spookiness as the third-rate human soldiers get stalked by the Cybermen, and an acting tour-de-force from Matt Smith as he throws himself into the dual role of the Doctor and Cyber Planner with manic energy. The question is never if the Doctor will be able to outwit the alien intelligence invading his thoughts, but how he'll do it while tied to a chair.
In a half season that's been filled with middling episodes that amuse without ever really coming together, "Nightmare in Silver" benefits enormously from Gaiman's focus on his siege scenario and the wider scope that the Doctor's mental battle offers. There are no loose ends or egregious leaps of logic, apart from the rather inexplicable decision to leave two children completely alone in a creepy theme park on an alien planet.
Gaiman also uses the Doctor's plight to shine a little more light on his relationship with Clara, with the Cyber Planner rooting around in his thoughts and memories of “the impossible girl,” while Clara's suspicious reactions to these duelling personalities says much about how she views the Doctor – and how much crazy she's willing to accept.
This material is the side dish rather than the main course and while the episode doesn't have the same depth of character insight that Gaiman brought to "The Doctor's Wife," it compensates by making the Cybermen, if not scary, then at least a credible threat. Rather than the clumsy stomping things of old, these models move fast, dismantle themselves to outwit opponents and can upgrade themselves to overcome any weaknesses in a matter of seconds. Add in the ability to enslave their victims almost instantly, and the prospect of three million Cybermen let loose on the universe actually feels like a genuine danger.
It's just a shame that the conclusion feels like a bit of a fudge. There's a great twist when it's revealed that Porridge is actually the long lost Emperor who ordered the destruction of a galaxy that was supposed to have wiped out the Cybermen, and Warwick Davis does excellent work taking a character who starts out as comic relief and slowly revealing him to be noble, sad and conflicted. He's a great actor, and it's nice to see him in a role that relies on that rather than his size. The same sadly can't be said of the two child actors playing Artie and Angie. It's never nice to criticise anyone so young, but they're just self-conscious enough in their performances to stand out.
But then the end relies on a narrative cheat in the shape of a planet destroying bomb that Emperor Porridge could have apparently activated at any time, automatically transporting everyone to the safety of a giant spaceship in orbit around the planet. It's a revelation that leads to an abrupt and rather anticlimactic solution to the Cybermen problem, and one that makes you wonder just how much of the episode's action was strictly necessary.
Also worthy of note are the sheer number of nods and references to other movies. As well as an obvious tribute to Charlie and the Chocolate Factory at the start, and the numerous similarities to Evil Dead 2 (complete with severed hand gag), there's a paraphrased line from Ghostbusters and Clara even exits the TARDIS by saying “See you next Wednesday,” the recurring line that appears in all John Landis movies. Cheeky, Gaiman. Very cheeky.
"Nightmare in Silver" isn't one of the all-time great episodes, but it does balance its crackerjack pace and moments of broad humour with a story that hangs together incredibly well, at least up until the awkward conclusion. Mostly, it reminds us of just how much fun Matt Smith is in this role, and if only for giving him an episode where he really gets to show his stuff, it's a more worthwhile entry than most this season.
Next week: the season finale, "The Name of the Doctor," which promises the return of River Song, Madame Vastra, Strax and Richard E. Grant from the Christmas special. It also promises to finally provide an answer to the question inherent in the show's title, but can they solve that riddle and explain who Clara is in just one episode, or has Steven Moffat built one mystery box too many? Fingers crossed.