Holistic Review: The setup, though reminiscent of previous stories, is terrifying and immediately engaging, but the plot starts to fall apart about two-thirds of the way through.

Cards on the table here: after In the Forest of the Night, I readily admit that I was more than a little nervous about letting Frank Cottrell-Boyce anywhere near a Doctor Who script again. But, having now enjoyed his latest effort, I'm glad that — like Peter Harness — he was given the opportunity to redeem his reputation. Smile may not be a perfect story, but it's got a superb hook and it's one of the most delightfully traditional Doctor Who episodes we've seen in a while.

Of course, it's impossible for Smile to avoid comparisons with seventh-Doctor story The Happiness Patrol, from which its basic premise is directly lifted: both stories involve future Earth colonies on which sadness is punishable by death, though fake smiles can provide protection. (I almost expected the Doctor to say "I'm glad you're happy" to an emojibot.) But where The Happiness Patrol uses this concept to tell a thematically-rich story about superficiality and the importance of sadness, Smile goes the simpler route of a rip-roaring, and terrifying, monster story. If you're sad on Terra Alpha, there's a decent chance that one of Helen A's undercover detectives, or a roaming Happiness Patrol, might catch you in the act and sentence you to eventual execution; but on Gliese 581 D, the omnipresent emojibots will immediately detect your emotional distress, and signal a cloud of Vardies to detach from the nearest wall and flay you to the bones within seconds. In Smile, the tension meter is upped considerably.

The teaser does a brilliant job of conveying this peril, as we get a glimpse of life in the city just after the full massacre has begun. As shepherd Goodthing, Mina Anwar completely sells the emotion of the moment, radiating sheer panic through her forced smile as she rushes to try to protect her friends from falling prey to the Vardies. As her sister Kezzia asks, "Is that smile supposed to look real? It's like you're standing in a wind tunnel." (Of Anwar's line deliveries, my particular favorites were "Smile, smile, smile!" and "Smile, really! Try!") But even though Goodthing's figured out the rules of the game, so to speak, she can't keep her horror at witnessing Kezzia's murder from showing through her plastered-on smile, and so she too is targetted for annihilation.

Into this death trap the Doctor and Bill blithely walk. The audience knows full well what threat the emojibots represent should either of them get upset, and though Bill's excitement at exploring her first alien planet keeps her smile beaming, the Doctor does insist on frowning balefully. It's a wonderful setup, and so much fun to watch the Doctor and Bill gradually puzzle out why the city is empty of colonists, and realize that they themselves are in grave danger too.

As in The Pilot, I adore that Smile begins with the TARDIS crew — even better, right where The Pilot left off — and for the first half hour, they're the only two characters in the story. I could watch the two of them solve mysteries all day long! I love that the Doctor is willing to ignore the rules to take Bill on a spin around the universe; it certainly says a lot about her character that she's the first person who's tempted him to ditch his responsibilities in seventy years. Capaldi and Mackie have such fantastic chemistry; both actors bounce beautifully off one another, and I'm getting more and more distraught at the thought that not just one but both of them might be gone at the end of the season. Please don't tell me Mackie is going to be leaving too. I don't want to hear it! LA LA LA LA LA! I keep trying to remind myself that nothing has been officially announced yet, but I have a bad feeling in my gut. Why oh why do I have to suffer through two and a half years of Amy Pond, but I only get one year each of Donna and Bill? Someone please clear a space for me so that I can throw a proper conniption fit.

Conforming to second-episode tradition, Smile presents Bill with her Companion Test: when the Doctor runs back into the city, will she hang around the TARDIS and wait, or will she run after him to help? (I think we all knew the answer.) What's great is that Cottrell-Boyce gives us a twist on the usual "let's see how the new companion handles her first real exposure to the Doctor's madcap life" scenario, because in this story, Bill's still figuring out the rules. She doesn't even know yet that the Doctor feels a responsibility to help any poor soul in trouble; she thinks they're just on a pleasure jaunt, and assumes there are authorities that can be summoned to take care of the colony. It isn't until Bill remembers the plaque on the TARDIS door — Advice & Assistance Obtainable Immediately — that she realizes the Doctor isn't just a traveller, but an intergalactic crusader who dives right in and solves problems himself rather than waiting for someone else to come along. As she tells the Doctor, "You don't call the helpline because you are the helpline." The funny thing is, I'd never even thought about that interpretation of this phrase, in all this time, and suddenly realizing how meaningful it is made me tear up a little.

I very much appreciate Bill's travelling behaviour: enthusiastic, but cautious. I was proud of her for pausing before diving into her exotic alien meal, to ask whether it would be safe for her to eat. (And I'm even more proud that she doesn't even bat an eyelid at tasting her fish-smelling blue Jell-O cube made of algae. And then she eats the whole thing! Bravo! Bill is my kind of travel buddy.) Like many an excellent companion before her, she chafes at the Doctor's attempts to keep her out of trouble, and I'm tickled that she's taking selfies of herself on her travels. After this week's episode, I feel I was not wrong in predicting that Pearl Mackie's performance was going to yield lots of delightful deliveries. I don't think I could cite a single line that she doesn't hit out of the park; I mean, just watch her performance (and Capaldi's!) as the Doctor and Bill examine their new emoji badges. Along with several moments that made me fall in love with Bill all over again — which I'll be citing below — I was utterly won over by her delivery of "Yeah, but... it's proper this time.", "Seriously! Why?", "You kept it.", "Aww. It's cute.", "Obviously.", her very realistic cry of "Doctor!" when she's grabbed by an emojibot (seriously, it sounds so natural coming out of Mackie's mouth! she was born to be a companion!) along with the look of terror on her face, her teary-eyed performance as Bill realizes there's a catastrophe in Earth's future, and her charming reaction — clutching at the Doctor's arm in excitement — when the building door ahead of them begins to open.

For the second week in a row, the twelfth Doctor is scripted to a tee. I love that where other Doctors' curiosity might manifest as wary intrigue (think Troughton or Smith) or grave concern (Tom Baker or Eccleston), the twelfth Doctor's comes out as snarky suspicion. But once he starts working out possible answers or solutions, he gets all excited and animated. It's fun to watch the twelfth Doctor puzzle out what's happened to the colonists, and his "advance robot building party" theory is a good one. But one of his best scenes is in the garden, as the Doctor deduces that the skeleton crew have been turned into fertilizer; Capaldi's expression and inflections indicate the Doctor's mounting concern and dread, as he tries to hope for the best but realizes he's rapidly failing. Once he works out what's happened to the skeleton crew, I appreciate that he tries not to frighten Bill too quickly but rather attempts to leads her slowly to the answer. (Of course, he winds up dumping a bucketful of skulls on her unsuspecting foot, but that's neither here nor there.) He's wonderful as a negotiator, directing his considerable experience toward the problem of ensuring that the humans and the Vardy can coexist peacefully. One of my very favorite elements of the plot is this: Ironically enough, it was during In the Forest of the Night that I first put my finger on the fact that Capaldi's Doctor is not best suited to overdramatic humor, a truth that was only hammered further home with every subsequent Christmas special. Typically, whenever an episode forces the twelfth Doctor to grin ridiculously, it just feels wrong. But in Smile, Cottrell-Boyce's script forces the Doctor to smile in a way that's deliberately unnatural, which turns what's typically a liability for the character into a resounding strength for both the plot and the creep-o-meter. (Mr Cottrell-Boyce, I do think you're winning me over.) Love Capaldi's delivery of "See? Happy.", and "Not even locked. They were expecting to live in peace."

Unfortunately, though, as the plot starts to get more complicated — right around the time that the Doctor leaves to search out the engine room — it also starts to fall apart a bit. Where the story was totally engaging, niggling questions begin to arise, and there's a sense that the script is glossing over some important points in order to quickly tie the plot up with a neat bow.

• My first problem is with the map: they really try to make it match the visuals, both by having Bill interact with it as she navigates the Doctor to the engine room, and by representing the Doctor's location with a blinking blue dot, which by rights should eliminate all problems. And yet the descriptions just don't always match up. The Doctor does actually seem to take the most direct route to get there, but Bill confuses matters when she tells the Doctor to go "down" — meaning, apparently, "straight ahead" — but traces a completely different route that would take the Doctor far out of his way. Then later, as Bill says "the engine is in the middle of a big empty space", the Doctor's blue dot appears to be coming down a passageway that he was previously nowhere near; but by the time she gets to "Uh, there should be a ladder...", the Doctor's blue dot has returned to its previous position. Not to mention the various ladders and staircases Bill mentions that are nowhere to be found on the map.

• Aside from the shepherds, the first colonist to awaken is Steadfast, a doctor; so we can perhaps assume that the second wave of awakenings begins with the most critical people. Sooooo why is Praiseworthy awake before anyone else, and what set off his pod early? It feels annoyingly like a plot detail for the sake of convenience, especially as Praiseworthy serves practically no purpose in the story: Bill drags him into danger, then somehow loses him, after which Praiseworthy wanders around the empty city under imminent threat of death until the climax.

• One gets the impression that the Doctor's sabotage will cause the engine to blow up relatively quickly. So how does he think he has time to (a) flee the spacecraft, the building, and the city before it blows, or (b) go gallivanting off and explore the pod room? (Shouldn't he have considered materializing the TARDIS in the engine room to facilitate an immediate getaway?) Now, this might be related to two other questions I had, namely:
  1) What's the "big empty space" that so concerns Bill, which ends up having zero impact on the plot? (Except that it locates the engine on a very unsafe rail-less bridge that makes about as much sense as situating the 'off' switch behind the series of killer fans.)
  2) Why does the Doctor and Bill's conversation cut from "We can't blow up the city" (in the pod room) to "Why?" (as they descend the ladder), which makes it look as though the pod room is directly above the engine room?
  Is it possible that the pod room really is above the engine room, and that's what the big empty space is meant to represent? (But if that's the case, why isn't the pod room visible in the shot of Bill and Praiseworthy preparing to go down the ladder?)

• Why does the Doctor only come up with the idea to reboot the robots after realizing that they're alive? What difference does that make? He could reboot them just as easily (in fact, probably more easily) if they were non-sentient machines. This solution seems too simplistic.

• How does rebooting the robots, and even erasing their memories, remove their paradigm that unhappy people must be killed? How can the Doctor guarantee that they won't eventually start murdering grieving people again? (The implication is that he's also completely removed their imperative to serve the humans and guarantee their happiness, but that's never explicitly confirmed.)

The other really big hurdle in the plot is that — as has so often been the case in the revival — the Vardies turn out to be acting with benevolent intentions, their murderous rampage nothing more sinister than the result of an overly-literal machine mind misunderstanding its directive. In theory, this is a fine idea — we might note that it worked to good effect in The Empty Child — but the problem in Smile is that failing to program your robots with Asimov's First Law seems like a huge oversight. However did the inventors of these robots not realize that the Vardy might decide unhappiness needed to be wiped out with extreme prejudice? (Granted, the Doctor says that they've expanded their original programming, but still: you always hardwire your robots with the First Law, precisely to keep something like this from happening.) So the very idea that these robots might innocently turn murderous, and wipe out their human colony in an unbelievably misguided attempt to protect them, is quite hard to swallow.

But if you can look past this egregious programming fail, the emojibots and the Vardies make for a memorable monster team-up. The Vardies — omnipresent, able to detach themselves from any surface, and swarm-based — are creepy no matter how you look at it. When you add in their ability to devour you within seconds, leaving nothing but a pile of dusty bones, it really does give the impression that the entire city is a giant maw just waiting to devour you the moment you set a foot wrong. There's more than a little similarity between the Vardies and the Vashta Nerada, too; the main differences between them are that the Vardies are robotic, visible (just), and deterred by smiles rather than light. But both of them are all around you, all the time, and one mistake will have you reduced to nothing more than a pile of bones. (But can someone please explain to me when we use Vardy vs Vardies as the plural? Is it Vardy for the species, and Vardies for a swarm?)

The emojibots are a super concept, potentially twee, but still a natural extension of how humans might be using language thousands of years in the future. As much as I personally disagree with the widespread notion that text-speak and emojis will eventually dominate the language, I think Cottrell-Boyce may have nailed it: spoken and written languages will remain as popular as ever, but emojis could turn into a kind of lingua franca to facilitate basic cross-cultural communication. I mean, we already see it happening with iconography like the floppy disk, recognized (more or less) globally as a symbol for "save", even decades after floppy disks themselves have become obsolete. Like some of the best monsters, the emojibots are outwardly cute — especially when they display that big grin emoji! so happy! — but can turn threatening in a heartbeat. The sound they make as their display transitions from "happy" to "concerned" is enough to make your heart sink, and when the display changes to that terrifying death's-head skeleton face with skulls for eyes, yeeesh. That's downright spine-chilling.

The patches are a neat idea, too, always displaying your mood but never letting you see it (to keep from influencing your mood). I'm not entirely certain that I get the point of them, interactionally speaking, unless I extrapolate from the Doctor's theory and hypothesize that they're not meant for human-to-human interaction. They're purely a feedback system for the emojibots, enabling them to keep tabs on the quality of their work and the Vardies'. In which case it makes sense that there might be a social taboo (under ordinary circumstances) against looking at someone else's badge, thus encouraging people to maintain eye contact when they meet. Bill seems appreciative of this idea, possibly because it's a partial solution to that old "everyone these days stares at their phones and nobody knows how to hold a proper conversation" gripe that's been going around since the advent of smartphones. Though one assumes that staring at a tablet would still be more socially acceptable than staring at someone's emoji-badge, so there's not necessarily any reason why the badges would kickstart more face-to-face conversation over the dinner table. But still, it's a nice idea.

I must give major kudos to Cottrell-Boyce for, in one single scene, helping me to understand Nardole better than the three previous episodes combined. Granted, his characterization as an overprotective house mother is basically brand-new as of this episode, but it makes so much more sense and gives his character a more defined purpose. I suspect I also like it because "stern manager" is also far less whimsical than "meta-commentary guy" or "silly coward". I'm also tickled that both Bill and the Doctor seem to find Nardole annoying this week; how dare he shut down their fun! In future, more of this Nardole, please. Having a more defined personality is also helping his jokes land better, partly because they're less puerile and partly because they're rooted in his characterization and thus coming from an understandable mindset. And maybe also because Steven Moffat isn't scripting him. See how right I probably was?

After the refreshing diversity of season 9, I'm so pleased to see that it's continuing into season 10; most if not all of the shepherds we see are Anglo-Indian, and the early-rising colonists are an ethnically diverse group. (Also, they have cool clothes, particularly those triangle-patterned hoods, and I love that the shepherds are wearing a braided Princess Leia hairstyle.) As I mentioned earlier, Mina Anwar is the standout of the group, but I enjoyed Kiran Dadlani's performance as the upbeat and bewildered (and doomed) Kezzia. Kaizer Akhtar isn't called upon to do much as Praiseworthy, besides look disconcerted and on the verge of tears, but he gives a convincing performance. Likewise, Ralf Little has basically one scene as Friendly!Steadfast and two scenes as Shouty!Steadfast, so his character goes from zero to sixty almost immediately. Meanwhile, poor Kalungi Ssebandeke makes the credits even though all of Nate's lines apparently got cut.

As much as I enjoyed Laurence Gough's direction last week, I was really impressed this week. The whole episode looks gorgeous and filmic, my particular favorite shots being the Doctor and Bill reflected in two panes of glass on the Palau de les Arts Reina Sofia as they race out of the city, and the tease of Bill's badge turning to a "wow" emoji. But it's really hard to single anything out when the whole episode looks this good. Of course, it doesn't hurt that he had such a sumptuous location to film; the museum complex, with its fascinating futuristic architecture, allows for so many interesting angles and shot compositions, and Gough takes full advantage of the natural (well, man-made!) scenery.

I'm full of awe for the location scouts who discovered La Ciudad de las Artes y las Ciencias, which has rapidly shot to the top of my must-see list whenever I finally manage to visit Spain. I can't wait to hear the story of how they found it, because it's an absolutely perfect stand-in for a futuristic city, and the scenery from every angle is nothing short of stunning. It makes me very curious to see more of Santiago Calatrava and Félix Candel's architectural work. Even though I knew the episode had been filmed in Valencia, the buildings looked so unreal that I couldn't help but wonder if the whole thing were a matte painting or something.

And speaking of matte paintings, the effects team did a stellar job of seamlessly painting La Ciudad de las Artes y las Ciencias into a vast field of ripening wheat. It goes a long way toward worldbuilding on Gliese 581 D, and — in keeping with Cottrell-Boyce's desire to present us with a utopia rather than a dystopia — the cheerfully sunny vista is a far cry from your typical quarry / frozen / jungle planets. In fact, I'd say the same about the sun-drenched city with its many tranquil pools, and buildings so white that the reflected sunlight is almost blinding. It makes for a really fun and welcome change.

The Vardies are likewise a seamless effect; unsurprisingly, they look great flying around in the sky like a swarm of bugs (that tends to be an effect that CGI can do really well), but the shots of walls and buttresses and even an entire dome dissolving into Vardies are really impressive too. I especially loved the distant shot of the shattered-looking dome after a huge swarm of Vardies has separated from it to attack the newly-awakened colonists. There's also a nice subtle effect in various parts of the city of bursts of light racing down bridges and hallways, like neurons firing. We're never told what it's meant to represent, but it adds to the impression that the filming locations are more than just fancy modern-day buildings.

I loved Murray Gold's creepy score this week. It's excellent throughout, but for me the real highlights were the music as the Doctor and Bill see the Vardy for the first time, when the emojibot's display changes from happy to concerned, and as the Doctor and Bill flee the city.

Minor points:

• Bill continues her tradition of questioning 53 years' worth of unspoken Doctor Who rules by asking: "Do I have to sit somewhere? Are there seatbelts?" Oh, are there ever.

• I have to disagree with her suggestion to bring the chairs closer to the console, though. He'd need six chairs to enable him to reach all the controls while sitting down, and six chairs would get in the way like crazy. Bill clearly hasn't yet seen the way the Doctor skitters around the console! (She would've hated the classic series console room, which practically never had a chair after the Hartnell era!)

• Adorable Bill Moment #1:

  Bill: "And what if I steal it from you?"
  Doctor: "On you go, then."
  Bill: "Oh, I dunno how it works!"

• Brilliant cut after Bill's last line to Kezzia's badge, which displays a beaming grin:

  Doctor: "Past or future?"
  Bill: "Future."
  Doctor: "Why?"
  Bill: "Why do you think? I wanna see if it's happy."

• So, as much as I love the teaser scene, it did occur to me that "Brace yourself!" was really not quite sufficient preparation for the shock that Goodthing was about to deliver, nor sufficient incentive to keep Kezzia smiling. What I would have said is something like: "I'm about to tell you some very bad news, but you have to keep smiling no matter what I say, because if you don't, the Vardies will murder you." Then I would cheerfully announce that all her friends are dead. (And Kezzia would be all, "whatever, weirdo!" and completely ignore me and get shocked by the news and then get eaten anyway. Assuming she made it that far, and didn't panic at the part about murderous Vardies. But at least I would have tried my best.)

• A delightful twelfth-Doctor moment:

  Bill: "Well, what if you get lost, or stuck or something?"
  Doctor: "I've thought about that!"
  Bill: "And?"
  Doctor: "Well, it would be a worry, so best not to dwell on it. Look at this building, look at it!"

• Cute line for Bill. (I'm reminded of Spike's line, after catching Buffy and Angel mid-liplock: "Most people don't use their tongues to say hello. Or, I guess they do, but...")

  Bill: "Ahh, your voice just came out in my ear... I mean, I know voices go into ears, but..."

• Followed by this very excellent question to which I would also want an answer!

  Bill: "Hang on, is there a mute button though? Like, what if you're in the loo?"

• I feel like the Doctor isn't often given really good one-liners, so I'm pleased that Cottrell-Boyce managed to work in not just one:

  Doctor: "I'm not that fond of fish. Except socially, which can complicate a meal like this."

• ...but two:

  Doctor: "I met an emperor made of algae once. He fancied me."

• Skipping back in time a tiny bit, I must flag this assertion with an "ummmmmmmm...?"

  Bill: "That's good, isn't it? In the future, we don't eat living things, we eat... algae."

• OH MY GOODNESS I'M SO GLAD BILL SAYS THIS!!! She like totally read my mind, winky emoji. But seriously, this was about to annoy me. (And Mackie's delivery made me LOL.)

  Bill: "Two portions, one portion. Is there gonna be food sexism even in the future? Is this bloke utopia?"

• Whew, the dialogue is zinging! On learning that the Doctor has two hearts:

  Bill: "Does that mean you've got really high blood pressure?"

• But wait, if the colony is growing wheat and herbs and vegetables, then why are they serving Bill flavored cubes of algae? Is the fresh food still being grown and processed? Is the skeleton crew on rations until the rest of the colonists are revived?

• Also, one assumes the crops need water more than they need regular showers of calcium-based mineral fertilizer?

• Adorable Bill Moment #2, as she breathes the aroma of fresh rosemary off her fingers. I always go wibbly when a companion takes the time to thank the Doctor for enriching their life! I "awww!"ed so hard at the rest of these adorable lines:

  Bill: "I'm smelling home... twenty light-years from home. Thanks for bringing me! This is a great day out."

• Why is the storage container for the bones located below the grinder? Shouldn't it be above so that it can automatically drop a skull or two into the pulverizer as needed? (Maybe the emojibots do it manually? But that seems like a silly waste of energy.)

• Yeeek. And this is indeed often true, although certainly not always, considering the top speed of some classic-series monsters.

  Doctor: "Do you know what it means when something chases you very slowly?"
  Bill: "What?"
  Doctor: "It means there's a reason that they don't have to run."

• Why don't the Vardy burst out of the walls to flay the Doctor and Bill while they're surrounded by emojibots and still looking frightened? (Perhaps because neither of them is on two-tears at the time?)

• I really like this quote, which gives some extra scientific grounding to the plot:

  Doctor: "Smiles aren't just smiles. Psychologically, they have a measurable effect on your mood states."

• Is it just me, or is this script giving Capaldi more great material than usual? His delivery of this line is just awesome.

  Bill: "How would massacring hundreds of people make me happy?!"
  Doctor: "How would massacring hundreds of people make me happy, smiley face."

• Ucch, I just can't stand their chemistry! and these endearing line readings from Mackie in particular! I'm going to die of joy and laughter and squee!

  Bill: "Doctor, I — I was thinking maybe next time we might go to Wiltshire, perhaps! Or Aberdeen."
  Doctor: "Ah, yes. Two thumbs up for Wiltshire-slash-Aberdeen."

• The Doctor and Bill have an awfully long way to run before they reach the city perimeter, and the Vardies are practically in their way (or they would be, if they stopped hovering in the sky and went down to ground level). So how do they manage to escape?

• Two more great lines for the Doctor, illustrating his sense of duty and ethics, and delivered with superb suppressed fury by Capaldi. One:

  Doctor: "That place is a living death trap! We can't just leave it with its mouth wide open!"

• Two:

  Doctor: "They're expecting a new Garden of Eden. What they are not expecting is to be the fertilizer."

• All of these emojis are delightful, but I think the "idea!" emoji might be my favorite!

• Adorable Bill Moment #3, as she ditches this "waiting around in the TARDIS" nonsense to pitch in with the Doctor. Mackie's performance kills me!

  Bill: "You couldn't even leave me serving chips, so I'm not gonna leave you."

• Adorable Bill Moment #4. I'm so glad to see they're not dropping the tutor/pupil relationship idea, and I love Bill's enthusiasm:

  Doctor: "Oh, you really are smiling, aren't you?"
  Bill: "D'you know why? You're an awesome tutor."

• Whyever did these colonists name their ship the Erehwon? Hopefully they're Samuel Butler fans, because otherwise it doesn't sound like a very optimistic name.

• When the Doctor opens the hatch and descends into the bowels of the ship, I was reminded of yet another story: State of Decay, in which the main building of the only city on a colony world conceals a spaceship which hides a secret in its depths.

• When the Doctor goes into the engine room and sets all the emojibots' bells off, I wonder why only one murderous emojibot (and no Vardies) comes after him?

• As far as we know, the Doctor has only met colonists fleeing one of three catastrophic events in Earth's future: the solar flares of the 29th century (The Beast Below); the solar flares which happened "thousands of years" after the 30th century (The Ark in Space), which some sources (including Lance Parkin's AHistory) date to roughly the year 6,000; or the destruction of Earth when the sun goes nova (The Ark, Frontios, The End of the World, and New Earth) sometime around the year 5,000,000,000. If Gliese 581 D is one of Earth's first colonies, then it surely can't be a response to any of those catastrophes? At the very latest, ignoring spin-off media, the Earth had interplanetary colonies as early as the 25th century (The Rescue, Colony in Space). So what's the catastrophe that propelled the Erehwon into space? (Maybe the Doctor is using "first" loosely? And I mean very extremely loosely. After all, Steadfast, like Vira in The Ark in Space, describes himself as a medtech, so they could be from the same time period. So, you know, if "3500 years into colonization" still counts as "one of the first"...)

• Why does a burning-hot jet of steam make the emojibot lose its grip? It's a machine, it shouldn't care. (And is it just me, or does it scream as it falls?)

• I love that when Praiseworthy wanders off the Erehwon, the ship unknowingly, but accurately, warns him to "be happy."

• The Doctor and Bill really seem to like having this conversation. (Granted, it is an effective one, and they act their socks off during its third iteration.)

  	18:15		Bill: "But, they're all dead? We saw them, it's too late!" Doctor:"We have to assume that there is a colony ship on the way. What do you think's gonna happen when all those people arrive? They're expecting the new Garden of Eden. What they are not expecting is to be the fertilizer!"
  	32:09	Bill: "So what happens now?" Doctor:"Now? Now they're all gonna leave this ship, find their friends and family mulched in the garden, and if they don't smile about that... it's going to be the end of the human race."
  	36:06	Bill: "So what'll happen when the new people meet the robots?" Doctor: [...] "I would say that a lot of the colonists had friends or family who were working here as shepherds. When they find out what happened..." Bill: "They'll be grief-stricken." Doctor:"And after that?" Bill: "A massacre."

• Incidentally, the Doctor's comment that a massacre on Gliese 581 D would be "the end of the human race" is perhaps a bit of an exaggeration (since we know there are other colony ships out there!).

• Again conforming to second-episode tradition, Bill — like Amy and Clara before her — tries to cheer up a distraught child.

• How do the Vardy dissolve one of the colonists without even touching her?

• I got really worried when the word "reset button" was mentioned, that maybe the dead colonists were going to come strolling back in and everything would be hunky-dory. Thank goodness the story didn't go that route!

• Is Praiseworthy really only going to drink half his juice?

• Why do the Doctor and Bill tell the colonists to "smile"? They don't have to do that any more. Is he just trying to force them to cheer up?

• I'm not exactly sure what need the Vardy have of rent payments, but at least it means they won't be the humans' slaves any longer.

• The end is delightful: I love that the Doctor is confident they've returned to "the exact moment we left" but the TARDIS, as in days of old, has gone haywire again.

• I must say, I'm really excited about next week's episode: not only to see how Bill handles being back in Victorian times (and how the Victorians react to her), but also because the frost fairs are such a cool setting for an episode, and one that I really know very little about.

So, the plot has some problems and the last 20 minutes aren't quite as good as the rest. Even still, the setup is a total winner, the scenery is breathtaking, and 25 minutes of a Capaldi and Mackie two-hander is apparently plenty to make me a very happy man. I love that this story doesn't rush us through Bill's reactions to exploring her first alien planet, and that, combined with some very effective scares, makes this episode an overall winner for me.