Holistic Review: Even the confusing backstory and deliberate misinformation can't drain the chilling ambience from this inventive, horrific tale.

Coincidence is a funny thing. The last time I was in England, this past April — April 16, to be precise — I spent a night in Hawkhurst, tracking down filming locations from The Curse of Fenric and The Androids of Tara. I got back to my hotel that night around 10 pm, and decided that, rather than sitting in the hotel bar, I'd do my nightly journalling in my room, with the television on in the background. Except I found it difficult to get much journalling done, because the program that happened to be on really drew me in. It grabbed me pretty quickly with an emotional hook, then started to turn creepier and creepier, until by the end I was utterly engrossed and tense. When it ended, I made note of a couple of names from the credits, and then went downstairs (where I could get wi-fi!) to look it up on IMDb: Inside No. 9, starring Steve Pemberton and Reece Shearsmith. Specifically, I'd watched episode 2.04, "Cold Comfort", which, like Sleep No More, also made use of CCTV as a gripping visual gimmick. I immediately told Gray that the series might be worth tracking down, so while he was here over the last couple of weeks, we burned through both seasons. (While there were a lot of really great episodes, "Cold Comfort" is still my absolute favorite.) And now, in a perfect display of timing, Shearsmith has cropped up in Doctor Who (fittingly, in season 9, episode 9, as DWM points out). It's a great shame that Gray had to fly back home the week Sleep No More aired, so we weren't able to watch it together. But thanks to our marathon of Inside No. 9, I now associate Reece Shearsmith exclusively with ordinary situations that have hidden sinister undertones and jaw-dropping final twists. While Le Verrier is hardly ordinary, Sleep No More provides a pitch-perfect recreation of the other two.

It certainly helps that the part of Gagan Rassmussen feels tailor-made for Reece Shearsmith's talents. Probably because it was, given that he and Gatiss are friends! (Incidentally, I spent the entirety of Inside No. 9 waiting for Gatiss to make an appearance... series three, perhaps? Hmm? It would only be fair, after all, now wouldn't it?) Like some of the very best characters from No. 9, Shearsmith's Rassmussen is mild-mannered on the surface but with some very unpleasant personality traits bubbling up, like his apparent selfishness and cowardice, or, you know, his eagerness to let the entire human race be eaten. Shearsmith is superb in the role, especially once Rassmussen's true motives are revealed, at which point he sounds very convincingly unhinged as he tries to persuade the Doctor that the Sandmen are an unstoppable, irresistible force. His sincerity, when he talks about having been converted to the Sandmen's flesh-eating cause, is so zealous that it's almost stomach-turning. Among his many great deliveries: "Look, you came to rescue the crew. I'm crew, so rescue me!", "And we're to be their food, and that's only correct.", "Things have been made very clear to me!", and "So new... evolving... hungry. Always so hungry."

You're probably getting the impression that I really liked Sleep No More. And you're quite correct! Right from the beginning, the story establishes a captivating tone — like Under the Lake, it has a very classic-series feel, and better yet, the atmosphere of the opening really knocks it out of the park, with the rescue crew breaching a dark and evidently abandoned space station (no way that could turn out badly) and Rassmussen's nonsensical-but-eerie warning "If you're going to watch, then pay close attention. Your lives may depend on it." By that point, I was hooked. In fact, I'd say that this is probably the first story by Mark Gatiss that really nails what I think of as his style: slowly-creeping horror occasionally lightened by humor, with a healthy dollop of nostalgia. I actually wasn't expecting there to be any nostalgia at all in Sleep No More, so I was tickled pink when the holographic singers appeared, crooning a superb version of the very fitting Mr Sandman. The cute lighthearted nature of the song makes a great juxtaposition against the darkness of the episode, particularly when it provides the soundtrack to the bleak scene of Nogata shooting Rassmussen full of bullets. Gatiss' aesthetic has always really appealed to me, and this episode is an excellent example of why.

Gifted with an episode like this to direct, Justin Molotnikov has swiftly made his mark on Doctor Who. People keep describing the episode's style as "found footage", but I'm not sure that's technically accurate, because this footage has already been curated, edited and broadcast. It's more like a mockumentary compiled from CCTV footage. Still, no matter what term we use to describe it, the category in general remains a popular format for horror films. Some would also say that the found-footage style is slightly (or extremely) overused these days, but for Doctor Who it's a fresh approach. Nor is it used purely as a gimmick, because the format turns out to be critical to the story's central twist. This style, of course, allows for some classic scary set-ups — like the slightly-obscured first-person POV as Chandra enters the room where he's about to die — which keep the audience constantly tense, scanning the frame for any sign of movement, and constantly expecting an attack at any second. Molotnikov does indeed use the shadowy corners of the frame very effectively, most notably in the scene with Deep-Ando attempting to get past the annoying door. As he frantically scans the corridors with his night-vision helmet, we get a brief glimpse of what appears to be a humanoid shape at the end of the passageway to his right; then, as we watch him from a distance, we can just make out the shadowy form of a Sandman entering the frame from the upper right-hand corner. I also loved the black-and-white shots, partly because they're artistic, partly because they lend those scenes a sort of classic-horror-movie feel, and partly because motes of dust are often visible floating through the frame, which initially seems like realism and only later gains a more sinister significance. Molotnikov's use of focus enhances the menace of the Sandmen, as in the shot of one stepping through the fire; the slight blurriness from the filter almost makes it look like a Harryhausen monster. And the first-person POV allows for some creative camera movements, like the moment when Clara glances back at the Doctor as she turns her attention to Rassmussen. I can't even imagine how difficult it must have been to set up all of these POV shots while simultaneously ensuring that every character's sightline remains consistent when the angle changes. And maybe it really isn't seamless, but aside from a couple of teensy-weensy continuity errors (as when Clara leans against the Morpheus pod twice), it certainly looks that way to me.

Obviously, the lighting crew and set designers also deserve a lot of the credit for the story's successful atmosphere. The red-lit corridors, often curved or angled so you can't see what's at the other end, seem designed to keep us tense and anxious. The many excellent shots of the Sandmen stalking through the shadows are a direct result of their talented handiwork.

From the promo, I'd been expecting this episode to be about some kind of Jekyll-and-Hyde sleep-deprivation monster, and I am quite pleased that the story didn't go the expected route. The Sandmen are certainly the creepiest monsters so far this season, particularly thanks to their design, with that unnaturally gaping maw, and their fearsome hungry roar. They're also inherently squicky, given that they're composed of dead human skin cells and mucus. Rassmussen and Chopra liken them to an infection, which is an unsettling comparison that gives them a certain zombie vibe, although technically it's the Morpheus machine that's the zombie-maker. The Sandmen, even though we never see it happen, are just going to eat you, not turn you. I appreciate that they have several limitations — they're not the fastest monsters on the block, they literally fall apart under pressure, and in this adventure, at least, they're blind. I'll grant you that they require some suspension of disbelief, which I'll be discussing momentarily, but if you can get on board with the sentence "What used to be sleep in your eye has turned into a carnivorous lifeform!" then you've conquered the episode's biggest hurdle.

The only real problem that I had with the story — and I admit, it was a big one — was that I never could get a handle on how the Sandmen operate. I kept hoping that either everything would fall into place by the story's end, or, failing that, that I'd be able to put the pieces together during my second viewing. Sadly, neither was true. The biggest questions I had were these:

• My most critical question first: we know that the Sandmen start out as the sleep dust in the corner of your eye, but how do they multiply and grow? My assumption was that the "infected" particles of sleep dust would accumulate after each time you went to sleep — so, 5 nights of sleep = probably 10 particles of infected dust, assuming one particle per eye per sleep cycle. This would make sense if you used Morpheus to power-nap for 5 minutes per day, or even better, to take several quick power-naps per day. But the story implies that one 5-minute cycle in Morpheus recharges your body for an entire month, so how long is it going to take to accumulate a Sandman if you're only yielding 2 sleep-dust particles per month? Clara suggests that "the longer you're in Morpheus, the more the dust builds up" but the whole point of Morpheus seems to be that you wouldn't stay in it for longer than 5 minutes. Sleep No More hints at an answer to this, when the Doctor reveals that Clara's infected: "You don't have a camera, Clara, but you will have by now. Sleep in your eye." This does imply that the body starts producing carnivorous sleep dust as soon as Morpheus alters the host's brain chemistry, even while the host is awake.

• Which might also address a related question, namely: where are all of these POV camera angles coming from? The Doctor informs us that "each little organic speck, just a tiny spy, drifting through the air" functions as a camera, even though we never see any "drifting through the air" shots. I was skeptical that the sleep-dust could really be filming everything, since people typically rub it away right after waking up, but if it's constantly being generated throughout the day — maybe even without the host even feeling it — then that does provide a possible explanation.

• My next-most critical question: how do the Sandmen consume people? The on-screen answer seems to be the most straightforward: they coalesce into giant lumbering monsters and... well, actually we don't know what happens next. We see one devour Rassmussen whole, which explains why they have a gaping maw, but the Doctor seems quite certain that "that's a direct attack, it's not how they operate. Dust grows, consumes the host." I'm not exactly sure why the Sandmen would be chasing people down if all they want to do is grow on them, but okay. The Doctor's theory is that "lying there in those pods, people are a ready-made food source." This suggests two possibilities. One: the Sandmen primarily hunt down people in Morpheus pods, as if they were tins of Spam. (If so, then the Doctor should be very suspicious of Rassmussen's excuse that "I hid in the only place I thought those monsters wouldn't find me!") Two: the Sandmen don't consume people at all. Rather, the evolving sleep dust in your eye wants to consume and convert you while you sleep. Perhaps once the Morpheus process has activated, all you need is one speck of evolved sleep-dust to start converting the rest of your cells, even while you're awake. This second hypothesis best fits the available evidence, except that it leaves the Sandmen completely out of the equation, and we know they're "hungry" too. Is there a competition for resources between the Morpheus pods, who want to convert all the humans into Sandmen, and the resulting Sandmen, who want to eat all the humans? As for Rassmussen's fate, either hypothesis could explain it. Perhaps the Sandmen have the ability to adopt the form of anyone they consume, like Zygon bodyprints; although, if so, why don't they assume any of the other dead crew members' forms? Alternatively, if my second hypothesis is correct, it's likely that the sleep dust consumed Rassmussen from the inside like a malevolent fungus. Is it possible that "Rassmussen" has been a Sandman simulacrum from the beginning?

• The Sandmen are made up of sentient particles of sleep dust that can conglomerate into a gestalt hive-being, yes? Well, I'd rather like to know how that happens. On one occasion, we see a Sandman simply appear in the locked room where Deep-Ando is hiding. Did it materialize out of thin air, or was the floor covered in a thick layer of sleep dust? Had we seen it coalesce in a whirlwind of particles, that might have answered my question. Likewise, what causes them to lose cohesion? We know that increased gravity can pull the Sandmen apart, but why does the one attacking them in the beginning fall apart? It looks as though 474 managed to sever its arm with the door, and it couldn't retain cohesion when separated from the main mass.

I had one other big question unrelated to the Sandmen: when exactly is Rassmussen filming and editing all of this? The implication is that he's filming his linking pieces in real-time, and perhaps his editing software is working in real-time too, to choose the best camera angles and stitch the video together as it's happening. This is just about believable, except that Nogata shoots Rassmussen dead, so when does he film the ending? The only solution that makes sense is my theory above: that Rassmussen was consumed by the Sandmen long ago, and either the creature that ate him is now disguising itself in his form, or Rassmussen himself has been converted. Since Sandmen evidently aren't injured by bullets, he just got right back up again once the Doctor and his friends were gone, and filmed the final scene while the station was plunging toward Neptune.

A couple of my minor unanswered questions seem to be present purely for the sake of atmosphere, and since they don't present plot problems, I'm okay with that. Namely, why does the Morpheus pod snatch Clara? (Was the pod programmed to behave like a virus-infected host unconsciously trying to spread the infection? Is it possible this is actually not a minor question, but rather a major plot point, the repercussions of which are yet to be fully understood?) And, why were there bags of dripping bloody meat inside the walk-in freezer? (Were they the original crew, being kept in the larder for later consumption? ...no.)

And then there are the few other questions I had, like why the grav shields went offline, or what caused the sudden fire, or how the sleep dust spores infect people, or why Patient Zero would be spending his 5 sleepless years lying inside a Morpheus pod. What's very, very clever about this story is these confusing elements were actually deliberate misdirection. That really didn't sink in for me until my third viewing, at which point I finally got it. The first two events were included purely for effect (unless the failing grav shields were part of the distraction Rassmussen mentions, while he relocates the pod onto the rescue shuttle), and the mentions of spores and Patient Zero were only intended to mislead the Doctor. And I really like it. As you well know, I ordinarily get extremely annoyed when things happen just because they look good, or because the plot needs them to happen, rather than being internally motivated. Even though that's exactly what's happening here, it works because Rassmussen has rigged the entire storyline for maximum effect, in order to make the narrative more exciting and gripping, and thus keep us glued to the screen. It's as if the Doctor and his friends have stumbled onto a film set without realizing it, except that the danger is very real. I've never seen a story like this before! What I love so much about this is that it's a brilliant way to make us think that we're getting an RTD-style freewheeling plot, when actually the apparent freewheeling is all part of the master plan. And I feel sure this is the first time we've seen a villain who spills all his secrets to the Doctor but for once isn't telling the truth at all, so the Doctor only thinks he's defeated him. It's such a creative twist on the "unreliable narrator" so common in first-person-POV fiction, but given a visual-media spin. In those stories, you never quite know if you can trust what the narrator is telling you, because they might be distorting the story for their own ends, maybe to make themselves look good, or maybe just because they have a bad memory. (One of the best novels I've read in this style lately is Emma Healey's Elizabeth is Missing, which I bought on that same trip to England in April 2015!) Here, the story is also being manipulated for the author's own ends, unbeknownst to us and unbeknownst to the Doctor, who thinks he's eradicated the Sandmen's menace when he sends Le Verrier Lab tumbling into Neptune. As do we, until we learn the truth about the story in the final scene.

And wow, what a final scene. I can't remember the last time that the Doctor really, truly, didn't win. In fact, not only did he not win, he was outsmarted! That never happens. But in this story, and with Reece Shearsmith in the lead role, that dramatic twist fits perfectly. Better yet, not only has the Doctor lost, it turns out that by watching this episode — which, fair dos, Rassmussen advised us not to do ("You must not watch this. I'm warning you.") — we've allowed ourselves to become victims of the Morpheus brain-altering signal. It's almost impossible not to get a sinking feeling in the pit of your stomach when Rassmussen reveals that we've all been infected, and I admit that earlier today, I did find myself rubbing the corner of my eye and then having a momentary jolt of fear. But Gatiss has saved the best for the very end, as Rassmussen rubs his own eye, which then crumbles away in a cascade of sand, leaving behind nothing but a jagged crater in his face. It's a horrifying, revolting image that sends chills down the spine. And, as his voice deepens into a possessed-zombie register, he points his finger at us and intones:

Rassmussen: "There's nothing left of Rassmussen any more. Only us. Only us. You will show this film to your family, won't you? And your friends. And everyone really. And then we can all be together. Dust to dust... Excuse me. You've got something there. Just in the corner of your eye..."

Absolutely chilling! Probably the most chilling ending of any Doctor Who story ever, actually. Not only has the Doctor failed to save humanity, he's failed to save us. As the episode winked out, I found myself giggling out loud, elated with fear. And I can't remember the last time any television had that effect on me. Not even Inside No. 9.

I don't have a whole lot to say about our two leads this week, except that both Capaldi and Coleman turn in excellent performances. For once, they're not split up during the episode, and the two of them bounce off one another in a most entertaining way. On the strength of this episode, I have decided that it's very unsettling when Peter Capaldi looks at you. In particular, he gives Clara some very odd stares, as if he knows something's wrong... although, just as with the duplicate Zygon soldiers last week, it later appears that he never suspected anything at all. Love Capaldi's delivery of "The human race." and the way he reluctantly agrees to the name "Sandmen." For Coleman, my favorite lines were her very funny delivery of "Oh yeah. Not just this." and "The wires, they were like snakes."

Thanks to Mark Gatiss' deliberate decision to give this story an Indo-Japanese cultural setting, it's delightful to see almost the entirety of the remaining cast filled by actors of Asian origin. See, other writers? It's not so hard really! Commander Jagganth Daiki-Nagata doesn't get a great deal of characterization, aside from being decisive and loyal to her team, which is unfortunate since she's the most senior crewmember and the only one who survives. But I really enjoyed Elaine Tan's performance (and Geordie accent!). Nice delivery of "He's right, man. It's amazing." Much more successful, in my opinion, was Osamu Almi-Chopra (Neet Mohan), who I disliked at first sight. He came across as just plain angry and contrary, and his rudeness toward 474 didn't help matters. But as time goes by, and particularly once he's stranded alone with 474, we begin to see other sides of him. His initial antipathy toward her turns into protectiveness and even tenderness, he reveals that he feels an ethical obligation to keep the Sandmen from reaching Triton, and we see his vulnerability, to the point that Chopra actually became my favorite character. So I was really sad to see him killed off, especially since Mohan is probably the most naturalistic of the actors among the rescue team. (Oh well, Rassmussen did tell me not to get attached.)

474 (Bethany Black) gives us a nice glimpse into the questionable ethics of the thirty-eighth century, when soldiers are genetically engineered for low intelligence, cloned, and force-grown. You'd think a character like that wouldn't have much of a personality — the name "Grunt" ought to be very telling indeed — but Black brings out the character's childlike emotions, particularly her wonder and hurt. I find it interesting that 474 has a kneejerk response to physical aggression, even when she doesn't want to retaliate (as shown by the way she whimpers pitifully when she defends herself from Chopra), although oddly, this character detail never pays dividends later. The character's non-native-sounding English ("Chopra! Don't be anger.") is really enjoyable, too. However, I find myself torn about the message that the character sends. I was so excited that Doctor Who had finally cast an openly transgender actress in any role at all, much less a fairly major one, and I want to praise the series from the rooftops for doing it. But I was expecting her to be cast in an unambiguously cisgender female part, whereas 474 is definitely more of an androgynous role. It's not that 474 is actually sexless, despite being a clone — she's consistently referred to as 'she', and she finds Chopra attractive, even though he constantly rebuffs her for unclear reasons. But she's literally and developmentally a child, she's criticized by other characters for being less intelligent, she's dressed in stereotypically masculine clothing, and given stereotypically masculine personality traits (aggression and fighting). Am I being too harsh for expecting more? Or, worse, am I being sexist for wanting a transgender actress to be given a more stereotypically feminine character? After all, it doesn't really matter whether or not her character "acts" feminine, since real-life people — both cisgender and transgender — span the entire spectrum of gendered behaviour. Perhaps, in fact, it's actually better for the episode to point out that just because a person is gendered female, she doesn't have to look or act girly? I'm just so torn, only because it's such a pivotal moment for the visibility of transgender actors on television, and I want it to be just right. What I hope is that Black had some agency in the character's portrayal — which it sounds like she did — and this is the portrayal she preferred. Anyway, no matter what, I still commend the writers and the casting team for their much more diverse pool of guest actors this year. I'm also vicariously thrilled by her casting because Black is obviously a huge Doctor Who fan (even more knowledgable about the series than I am), not to mention a delightfully funny person, so, just like with Frank Skinner last year, it's super-cool to see her get the opportunity to appear in it. Loved Black's delivery of "Last pod. This pod! Not empty." and the way she pushes at Chopra to get him to leave her behind.

Of the characters with less screentime, Haruka Deep-Ando (Paul Courtenay Hyu) is an immediately likeable character, with a cheery disposition and a sense of humor. Zina Badran is brilliant as the Morpheus Presenter, so professional and yet chummy, trying to sell us on such a horrific concept. And then we have the station computer. Where has Nikki Wilson been hiding?! I mean, aside from in the producer's chair. She needs to act more often! As the computer voice, I honestly found her to be one of the episode's highlights. Her delivery of "In order to enter rooms, everyone must do the song. It's very amusing." and especially "Now you're just being silly." would've made me laugh out loud if I hadn't been so quivery with nerves at the time.

I haven't talked about the effects yet, but they're fantastic. The box-out character introductions look really slick, and immediately give the impression of a budget that I'm sure the episode didn't have, especially given its money-saving re-use of corridors. The glowing blue Morpheus cables look unearthly and just a tiny bit malevolent, and it's yet another clever budgetary move — not to mention avoiding a potentially-cheesy effect — not to show the cables grabbing Clara. The exterior shots of Neptune are gorgeous (and Neptune's always been my favorite planet in the solar system, so I'm really excited that we've finally had a Doctor Who story set there). I suppose the effect of the Sandmen dissolving does look a tiny bit fake, but overall it's believable, and there are some really nice touches, as when puffs of sand get caught in an eddy of a breeze. The Sandmen slowly losing mass as a result of the gravitational increase looks fantastic, as I think does Rassmussen's dissolution, particularly the gradual way his face crumbles. In fact, that whole effects sequence — as one of Rassmussen's eyes falls away in a stream of sand, and his voice turns deep and menacing — is utterly freaky.

Finally, Murray Gold's music, which again doesn't really stand out, but maintains the creepy atmosphere and a high level of tension throughout, especially during scenes like their escape from the freezer. The background noises, especially in the opening sequences as the TARDIS crew and the rescue team explore the station, are eerie and unsettling. Also, a big round of applause to the very talented Hologram Singers (Natasha Patel, Elizabeth Chong, Nikkita Chadha, Gracie La), who harmonize beautifully on Mr. Sandman.

And I love the multiple interpretations of the title. It's a Shakespeare quote, it's an alternative slogan for Morpheus, and it's a pretty accurate description of what I'm sure a lot of children will be doing after watching this story.

Minor points:

• The one-off title credits are a fun change, although I must admit that on first viewing, I completely missed the "Doctor Who" because I was so busy studying it for words and names!

• Why do there appear to be Cybermat graphics on the shuttle control panel display? Is it meant to be a representation of the shuttle itself? In which case I guess I should be asking why their shuttle resembles a Cybermat head-on?

• One bit of dialogue that I never did quite get... Why does Chopra continually gripe that Morpheus is "colonizing" sleep? Who are the colonists?

• One thing I thought was very clever is that Sleep No More gets out its giggles early, frontloading a lot of really funny dialogue so that you know the story could be a comedy if it wanted to be... and thereafter devotes itself to tension and scares. (And I love Coleman's delivery of her second line.)

  Clara: "Looks like a Japanese restaurant." (gasps with excitement) "Have you brought me to a space restaurant?"
  Doctor: "People never do that, you know."
  Clara: "Do what?"
  Doctor: "They never put the word 'space' in front of something, just because everything's all sort of high-tech and futurey. It's never space restaurant or space champagne or, or, or space, you know, hat. It's just restaurant, champagne, or hat. Even if this was a restaurant."
  Clara: "What about space suit?"
  Doctor: "Pedant."

• Super comic timing by Capaldi and Coleman:

  Nagata: "Engineering stress assessors?"
  Doctor: "Yes. Yes, we are. We're here to, er, er..."
  Clara: "We're here to, er... to, er —"
  both: "...assess..."
  Clara: "...stress."
  Doctor: "Stress..."

• Score one for Clara!

  Doctor: "Theories?"
  Nagata: "Could be anything. Meteorite strike, space pirates..."
  Clara: "Ah! See? Not just pirates. Space pirates."

• Love Capaldi's delivery!

  Nagata: "Right. You're to consider yourself —"
  Doctor: "Part of the furniture!"
  Nagata: "...under my command."

• And another brilliant delivery by Capaldi:

  Clara: "I still don't know where we are."
  Doctor: "Indo-Japanese."
  He licks his finger.
  Doctor: "Thirty-eighth century."
  He licks his finger again, and considers briefly.
  Doctor: "Tuesday."

• When the Doctor asks Clara to hold his hand, is it purely coincidence that the advancing Sandmen appear to be holding hands too? For a moment I had a flashback to Journey to the Centre of the TARDIS (perhaps understandably, since the Sandmen do slightly resemble the time zombies).

• Why do the rescue crew's communicators stop functioning? Is Rassmussen somehow blocking the signal, the same way he's redirected the Sandmen's visual feed?

• Ohh, I really don't want to nitpick this, but: the end of the story implies that anyone exposed to the Morpheus signal instantly becomes a willing plague carrier — at best subconsciously, at worst actively. (Otherwise, why on earth would we agree to show this video to our family and friends?) But Clara, who has presumably been exposed to an identical signal, never shows signs of persuading people to try out the sleep pods, wanting to propogate Morpheus, or turning into a saboteur.

• Quite honestly, this sounds brilliant. Sign me up, at least occasionally. I have television to catch up on.

  Morpheus Presenter: "The Morpheus machine concentrates the whole nocturnal experience into one five-minute burst."

• Okay, I'm souring on the concept now. Really? Must I?

  Morpheus Presenter: "All the chemical benefits of rest, but freeing up the nights to continue working, working, working, to get the edge on your competitor, to turn that extra profit."

• Probably my most laugh-out-loud moment of the story.

  Doctor: "But sleep is —"
  Morpheus Presenter: (reappearing) "Terms and conditions apply."

• I wondered too, Clara! Thank you for asking!

  Doctor: "Sleep is vital, sleep is wonderful. Even I sleep."
  Clara: "When?!"
  Doctor: "Well, when you're not looking."

• Spoooookyyyyyy!

  Doctor: "It's adaptable, it's clever..." (distant roar) "And it's coming for us."

• Capaldi is on fire this week!

  Doctor: "I'm in charge!"
  Nagata: "You have no authority!"
  Doctor: "No, but I'm... in charge!"

• For my first couple of viewings, I was sure there was a brief glimpse of a Sandman corporealizing as the Doctor struggled to activate Nagata's helmet. Then, on my third viewing, I finally did a freeze-frame and discovered that it was... a potted plant. Probably a (non-man-eating) ficus. There is, however, footage of the Sandman swallowing Rassmussen whole, although thanks to the jittery camera movements and the station shaking itself apart — perhaps the only moment in which the filming style is a downside — it's difficult to make anything out. (Also, I'm fairly certain that after swallowing Rassmussen, the Sandman seems to be wearing a boot on its left leg. Is that a clue...?)

• What, I wonder, would Rassmussen have done if the Doctor hadn't been able to repair the grav shields?

• Brrrr, Peter Capaldi.

  Doctor: "Every morning we wake up and wipe the sleep from our eyes, and that keeps us safe, safe from the monsters inside."

• Wait, no, maybe this was my biggest laugh-out-loud moment of the episode. (I'm not sure I trust him after that "Boneless" débacle...)

  Doctor: "You don't get to name things. I'm the Doctor, I do the naming."
  Clara: "All right, sorry."
  Doctor: "It's like the Silurians all over again."

• In attempting to distract the Sandmen so they can escape, wouldn't the Doctor have been wiser to rustle the Hanging Plastic Strips anywhere but exactly the spot they're planning to run through? That's not a distraction, that's summoning them!

• After all this great dialogue, now Gatiss trots out one of my pet-peeve clichés, for the third time in the last four stories. On this occasion, at least, it didn't feel quite as annoying, mainly because for once I'd actually guessed that the missing element was cameras. I'd been very proud of myself for immediately noticing when the viewer's POV switched to Clara's perspective, and realizing that it must be related to her use of the Morpheus pod, although for the longest time I couldn't figure out how that was going to become relevant. Things started to click when Nagata revealed that their helmets didn't have cameras — I'd been certain that they did, having looked for them the moment I realized that we were seeing the story from various POVs, and the lights built into their helmets had me totally fooled. (Sneaky designers!) However, I still have a couple of objections to the dialogue below. First: none of these camera angles show the corners of the ceiling, where one would most expect to find cameras (although perhaps we can assume that the characters themselves, who have been walking around this station for some time, haven't spotted any). Second: if there aren't any CCTV cameras on board Le Verrier, then where are those stationary black-and-white images coming from? (And, while we're on the topic, where does the TARDIS POV come from? Dust that's accumulated on the windows?)

  Doctor: "Look, there's one very obvious thing about it! Do you see it yet? ... What can't you see anywhere? Not in the footage, not on this ship."

• If the dust has been constantly watching them, how come the Sandmen don't always know where they are? Is it because Rassmussen is diverting the signal? Speaking of which, how exactly is Rassmussen hijacking the Sandmen's visual receptors?

• "I'm sure it'll be fine," the Doctor reassures Clara. "I'm sure you'll be fine." But he sounds very uncertain. Has Clara been cured? Because she's the only person still living who's used Morpheus mark 2. Nagata, along with everyone on Triton whom the Doctor goes to help, has only used the primitive first version. Let's all hope this isn't how Clara's being written out!

• What exactly is Rassmussen doing when Nagata shoots him? He can't be sending out the final edited copy of the film, because his eye is still intact, so he hasn't yet recorded his final entry... and anyway, some of the events in his film haven't happened yet. (All of which lends credence to my theory that this Rassmussen is a Sandman duplicate.) Is he preparing for takeoff, maybe? (It wasn't clear to me until my fourth viewing that they were back on the shuttle, and the Doctor does tell him to "turn off the engines, shut the ship down!") Whatever it is, he seems very determined to accomplish it before they can stop him.

• "We escaped from that cold storage room because they were blind," muses the Doctor. "It's like this is all for effect!" Is the Doctor implying that Rassmussen blinded the Sandmen for effect too? I assumed it was a side effect of his redirecting their visual feed. Why would blind Sandmen make for more rivetting television? Because it prolongs the chase, maybe?

• Also super freaky!

  Rassmussen: "There are no spores, no infection. The Morpheus process remains the same. An electronic signal that affects the sleep centres of the brain. Changes them. An electronic signal that's contained in this recording." (burst of static) "There it is."

• Chills up and down the spine... I love it!

  Rassmussen: "Compulsive viewing. I did tell you not to watch."

• Ohh, I don't want to nitpick this either! But... if the gravity has increased to the point that Rassmussen can't hold himself together, how does he manage to save and transmit the final edit of the footage?

For me, the enthralling atmosphere of Sleep No More is threatened only by the disorienting confusion of unanswered plot questions, but since I've been able to infer possible answers for most of those questions over subsequent viewings, I find I'm appreciating it a whole lot. It's a shame that the unintentionally confusing details combine with the intentionally confusing details to make the story initially seem like one big web of perplexity, but it just takes a few viewings to work it out. In fact, because there's so much going on in the episode, and so many details that I missed on my first few viewings, I get the impression that Sleep No More has even more nuances that I just haven't figured out yet, but when I do, I'll like it even more. I'm thrilled to hear that Gatiss has already been asked to write a sequel to this episode, so I'm looking forward to seeing the Sandmen again (and possibly getting some more concrete answers) in the near future...