Ah, the found-footage film. Popularised by The Blair Witch Project and imitated often since, it may be the most abused and overused novelty film-making technique in use today - I can count the number of good found-footage films on one hand, but that hasn't stopped everyone and their mothers from thinking that their films would greatly benefit from poor camera-work and a nauseous audience. So naturally, it was only a matter of time until Doctor Who picked it up.
Set on an abandoned space station, we follow a rescue team who were sent to investigate the lack of communications coming from the space station in question. They soon bump into Clara and The Doctor, and not long after they all run into the only surviving member of the space stations crew - the inventor of a sleep-replacement machine known as Morpheus.
In fairness, Doctor Who does at least attempt to do something somewhat original with the found-footage technique, but the pay off is nowhere near worth the cost of implementation. At several moments in "Sleep No More", Doctor Who broke my suspension of disbelief by showing me 'footage' from a character who isn't wearing a camera. Now, this does actually end up being part of the story and as such an intentional choice by the show - but you don't know that when you first notice it, so at the time you just end up wondering how the creators of the episode managed to mess up the concept of found-footage so badly. To make matters worse, when "Sleep No More" reveals that it did this on purpose you can't help but have your suspension of disbelief broken again while trying to reconcile this new information. The result? Multiple instances of being reminded that you are watching a TV show and taking you out of the moment, all just to explain why the found-footage technique is being employed in the first place, which itself ends up making very little sense.
Other than that, it's pretty much business as usual for what ultimately amounts to be nothing more than a sub-par 'base-under-siege' episode of Doctor Who. The monsters are imaginative if not somewhat far-fetched, the side characters are just about adequate enough to keep you interested in their fates and the whole thing has that 12A horror feel that is oddly soothing. Something that I thought I was going to like was the concept of the Grunt, a grown human whose intelligence is artificially limited and used purely as canon fodder - but I'm not over-exaggerating when I say that this ends up being nothing more than window dressing, completely removed from the story itself and serving no purpose at all.
Additionally, I was surprised to learn that "Sleep No More" isn't actually a two-parter. It's not that there are threads left over from "Sleep No More" that need addressing, it's that "Sleep No More" doesn't have a resolution. The Doctor ends the episode claiming that "none of this makes sense" while escaping the space station, and he's right - he doesn't learn what was actually going on in "Sleep No More", he doesn't stop the 'bad guy' and the episode simply ends. I barely feel like I actually understand what went down to be honest, and from what I gather online I'm not the only one who found "Sleep No More" to be difficult to follow.
Overall, "Sleep No More" is not a good episode of Doctor Who - in fact it may be a legitimately bad one, inherently flawed in multiple ways and (worst of all) somehow wasting the considerable talent of Peter Capaldi, making The Doctor boring to watch. It's forgettable, anti-climactic and predominantly a waste of time, an excuse for a gimmick that simply wasn't worth it. A low point of the season? No, because "The Magicians Apprentice" was a travesty - but not an episode anyone will ever actively want to rewatch.