Doctor Who: Sleep No More

"Don't watch it!"

Wow. That was brilliant. Genuinely chilling, possibly the scariest episode of Doctor Who ever, and certainly Mark Gatiss' best ever script.

The "found footage" nature of the episode means that it has to be bloody well shot, and it is. The future world is sketched out just enough- a colony on the Neptunian moon of Trition, Indo-Japanese and, in a nice touch, polytheistic. It's the 38th century and, clearly, the capitalist worship of work for its own sake is as bad as our world, with the invention of "Morpheus" to remove the need for more than a few minutes' sleep. So we can work more, of course. Heaven forfend that there would be any other reason.

The plot is fiendishly clever, at one point turning on the delightfully metatextual point that, in this episode of found footage, there are no cameras to be seen. Even more metatextual is the final, terrifying cliffhanger: everything we've seen has just been a charade. The real infections the footage... which we've just seen. Brilliant.

Also worthy of praise are Capaldi, for his extraordinary and gripping delivery of the exposition, and for the superbly effective appearance of the "Sandmen", which add so much to the episode. The idea of the Sandmen- monsters made from sleep dust which arise if we deprive ourselves of sleep for too long- are a decidedly Moffatian idea from Gatiss' pen.

Also worthy of praise, in a very interesting part, is Gatiss' former League of Gentlemen comrade Reece Shearsmith. It's nice to see some consistency in giving the casts northern accents- Nagata's lines are even scripted to be Geordie! 

So, yeah, right up there with the best. A sublime bit of telly. Interestingly, though, it ends with the threat still out there but, apparently, an unrelated episode next week. So what twist on the two-parter format are we getting here...?