Transmission: 14.11.2015.

Writer: Mark Gatiss.

Director: Justin Molotnikov.

Guest Starring: Reece Shearsmith; Elaine Tan; Neet Mohan; Bethany Black; Paul Courtenay Hyu; and Zina Badran.

"You must not watch this," warns Professor Rassmussen. That might not seem the brightest thing to say to entice viewers in – but it's actually remarkably clever. After all, if someone tells you not to do something, isn't that the very thing you're going to do?

The Doctor and Clara arrive on the Le Verrier Space Station where the Professor has created the Morpheus Machine. In five minutes, it can give you all the benefits of a good night's sleep, and then you don't have to rest again for another month. "Congratulations, Professor; you've conquered nature," the Doctor says. "You've also created an abomination."

It's used on the Indo-Japanese space station that orbits Neptune – but suddenly, everything goes silent.

This is a Doctor Who first: an episode comprised of 'found footage', ie. where the story is told through camera recordings, with characters not only addressing each other and the threat but also the audience. "This episode is assembled from footage found in the wreckage of a crashed space station," producer, Brian Minchin teased. "We're just putting it out as it was discovered."

Writer, Mark Gatiss finished the script back in March, and promises scares-a-plenty. "It's been quite a challenge to make because you have to break a lot of the usual rules in terms of what you can actually show," he says. "Anything you can do to shake the format up is very exciting and that's what we've done."

It's a very different tale to his previous two, The Crimson Horror (2013) and Robot of Sherwood (2014), both of which were humorous affairs (though the former remained admittedly dark). Gatiss has been working on the show since 2005, and his previous contributions include The Idiot's Lantern (2006), Victory of the Daleks (2010), and Cold War (2013).

Sleep No More will air on the weekend of the Doctor Who Festival, which Mark will be attending (and so will Lovarzi – so keep an eye out for us at Stall DW18!).

Guest star (and friend of Gatiss), Reece Shearsmith plays the creator of the Morpheus Machine, Rassmussen, and he says the found-footage angle of the episode was an interesting challenge: "Time was taken during filming to make sure we never broke the conceit of the episode, and so a lot of time was spent capturing the action from various characters POV's. It was quite meticulous and the action I think feels very raw and ‘captured’... It's very odd doing that because it is counter intuitive to the way you film anything else ever!"

Sleep No More airs on 14^th November on BBCOne at 8:15pm.